Treating 'Felt Sense of Anomaly'-Type Dissociative Experiences by Targeting Hypothesised Psychological Maintenance Mechanisms: A Single Case Experimental Design Series
Phase: NA
Conditions: Dissociation, Depersonalization, Dissociative Disorder
Sponsor: University of Birmingham

Study Title: Treating ‘felt sense of anomaly’-type dissociative experiences by targeting hypothesised 
psychological maintenance mechanisms: A Single Case Experimental Design series 
Internal Reference Number / Short title: Dissociation CBT Studies (DisCS). 
Ethics Ref: 23/NW/0163 
IRAS Project ID: 325448 
Date and Version No: Version 3.0, 4th December 2023 
 
Chief Investigator: 
Dr Emma Černis 
Assistant Professor of Clinical Psychology, University of Birmingham 
 
 
Sponsor:  
University of Birmingham 
 
Funder:  
University of Birmingham School of Psychology 
Conflicts of Interest: None to declare. 
 
 
Confidentiality Statement 
This document contains confidential information that must not be disclosed to anyone other than the 
Sponsor, the Investigator Team, HRA, host organisation, and members of the Research Ethics 
Committee and Regulatory Authorities unless authorised to do so. 
Sponsor statement:   
Where the University of Birmingham takes on the sponsor role for protocol development oversight, 
the signing of the IRAS form by the sponsor will serve as confirmation of approval of this protocol. 
 
 
 

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TABLE OF CONTENTS 
1. 
LAY SUMMARY ................................................................................................................................... 3 
2. 
SYNOPSIS ............................................................................................................................................. 4 
3. 
ABBREVIATIONS ............................................................................................................................... 5 
4. 
BACKGROUND AND RATIONALE ................................................................................................. 6 
5. 
OBJECTIVES AND OUTCOME MEASURES .................................................................................... 8 
6. 
STUDY DESIGN .................................................................................................................................. 9 
7. 
PARTICIPANT IDENTIFICATION ................................................................................................... 9 
7.1. 
Participants ..................................................................................................................................... 9 
7.2. 
Inclusion Criteria ............................................................................................................................ 9 
7.3. 
Exclusion Criteria ......................................................................................................................... 10 
8. 
STUDY PROCEDURES ..................................................................................................................... 10 
8.1. 
Recruitment .................................................................................................................................. 11 
8.2. 
Screening and Eligibility Assessment............................................................................................. 11 
8.3. 
Informed Consent ........................................................................................................................ 12 
8.4. 
Randomisation .............................................................................................................................. 12 
8.5. 
Blinding and code-breaking .......................................................................................................... 13 
8.6. 
Assessments ................................................................................................................................. 13 
9.6.1  ‘Standard’ Assessments ................................................................................................................ 13 
9.6.2  ‘Target’ Assessments ................................................................................................................... 14 
9.6.3  Qualitative Feedback ................................................................................................................... 14 
8.7. 
Early Discontinuation/Withdrawal of Participants ........................................................................ 14 
8.8. 
Definition of End of Trial ............................................................................................................ 15 
9. 
STUDY INTERVENTIONS ............................................................................................................... 15 
9.1. 
Study 1 – Negative Cognitive Appraisals of Dissociative Experiences ........................................... 16 
9.2. 
Study 2 – Perseverative Thinking (Rumination) ............................................................................ 16 
9.3. 
Study 3 – Affect (Emotion) Intolerance ........................................................................................ 16 
10. 
SAFETY REPORTING .................................................................................................................. 17 
10.1. 
Definition of Serious Adverse Events ........................................................................................... 17 
10.2. 
Reporting Procedures for Serious Adverse Events ........................................................................ 17 
10.3. 
Events exempt from immediate reporting as SAEs ....................................................................... 18 
11. 
DATA ANALYSIS .......................................................................................................................... 18 
11.1. 
Statistical Analysis ......................................................................................................................... 18 
12.1.1 Quantitative data ........................................................................................................................ 18 
12.1.2 Qualitative data .......................................................................................................................... 18 
11.2. 
Sample Size Determination ........................................................................................................... 18 

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11.3. 
Analysis Populations ..................................................................................................................... 19 
11.4. 
Decision points and stopping rules ............................................................................................... 19 
11.5. 
The Level of Statistical Significance .............................................................................................. 19 
11.6. 
Procedure for Accounting for Missing, Unused, and Spurious Data. ............................................. 19 
12. 
DATA MANAGEMENT ................................................................................................................ 19 
12.1. 
Source Data .................................................................................................................................. 19 
12.2. 
Access to Data .............................................................................................................................. 19 
12.3. 
Data Recording and Record Keeping ............................................................................................ 20 
13. 
QUALITY ASSURANCE PROCEDURES ..................................................................................... 20 
13.1. 
Risk assessment and monitoring ................................................................................................... 20 
13.2. 
Trial committees ........................................................................................................................... 20 
14. 
PROTOCOL DEVIATIONS .......................................................................................................... 21 
15. 
SERIOUS BREACHES ................................................................................................................... 21 
16. 
ETHICAL AND REGULATORY CONSIDERATIONS ............................................................... 21 
16.1. 
Declaration of Helsinki ................................................................................................................. 21 
16.2. 
Guidelines for Good Clinical Practice ........................................................................................... 21 
16.3. 
Approvals ..................................................................................................................................... 21 
16.4. 
Other Ethical Considerations ........................................................................................................ 21 
16.5. 
Reporting...................................................................................................................................... 22 
16.6. 
Participant Confidentiality ............................................................................................................ 22 
16.7. 
Expenses and Benefits .................................................................................................................. 22 
17. 
FINANCE AND INSURANCE ...................................................................................................... 23 
17.1. 
Funding ........................................................................................................................................ 23 
17.2. 
Insurance ...................................................................................................................................... 23 
17.3. 
Contractual arrangements ............................................................................................................. 23 
18. 
PUBLICATION POLICY ............................................................................................................... 23 
19. 
DEVELOPMENT OF A NEW PRODUCT/ PROCESS OR THE GENERATION OF 
INTELLECTUAL PROPERTY .................................................................................................................. 23 
20. 
ARCHIVING................................................................................................................................... 23 
21. 
REFERENCES ................................................................................................................................ 25 
22. 
APPENDIX A:  STUDY FLOW CHART ....................................................................................... 28 
23. 
APPENDIX B:  SCHEDULE OF PROCEDURES ........................................................................ 29 
24. 
APPENDIX C:  AMENDMENT HISTORY .................................................................................. 30 
 
 
 

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1. LAY SUMMARY  
Why is the research important?  
Dissociation involves distressing feelings of unreality and disconnection. Evidence suggests it is 
particularly common amongst people with existing mental health difficulties, where it has been linked 
with greater clinical severity, poorer treatment response, and increased self-harm and suicidality. 
However, there are currently no psychological treatments for dissociation that have been developed 
from a scientific understanding of its underpinning psychological factors. We would like to develop 
such a treatment. Previous research has identified potential factors, and we have developed three brief 
psychological interventions each targeting one factor. By precisely targeting a factor with therapy, any 
resulting ‘downstream’ effect on dissociation would indicate that the relationship between the factor 
and dissociation is causal – not just correlational. This case series will therefore test whether three 
factors (cognitive appraisals; worry; difficulties tolerating emotions) have a causal relationship to 
dissociation. This information will be crucial for building a case for support to fund larger, more 
rigorous tests of the factors and interventions. 
What will happen in the study?  
Three studies, each with four participants, will test a different psychological factor. Participants will be: 
adults (16+ years); on for the caseload of an NHS mental health service; high scorers on a dissociation 
questionnaire. Participants will complete assessments before and after treatment, and at a one-month 
follow-up. The studies follow a ‘multiple baseline design’, meaning that all four participants for that 
study will complete their baseline assessment in the same week, and then be randomly allocated to wait 
either one, two, three, or four weeks before starting the intervention. The intervention will consist of 
four therapy sessions taking place within a five-week ‘window’. Taking part in the research is voluntary. 
Before deciding whether to participate, we will explain the study and answer any questions. 
How will results be measured?  
Daily, participants will record a score for their dissociation and the psychological factor being targeted. 
At baseline, post-therapy, and follow-up we will also measure their levels of other factors related to 
dissociation (i.e. those not targeted by the therapy). Additionally, we will request feedback from 
participants about the therapy at the end of their involvement, in order to improve it in future. 
Ultimately, if successful, these interventions could form a pilot therapy for further testing and 
development. We hope this would mean fewer people struggle with the challenges of dissociation. 
 
 
 

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2. SYNOPSIS 
 
Study Title 
Treating ‘felt sense of anomaly’-type dissociative experiences by targeting putative 
psychological maintenance mechanisms: A Single Case Experimental Design series. 
Internal ref. no. (or 
short title) 
Dissociation CBT Studies (DisCS). 
Study pre-registration 
Intended registry: ClinicalTrials.gov 
Sponsor  
University of Birmingham 
Funder  
University of Birmingham School of Psychology via new starter fund awarded to EČ.  
Clinical Phase  
Phase 1: Single case study / case series 
Study Design 
Multiple baseline single case experimental design (x3).  
Participants 
Adults (age 16 and above), on the caseload of NHS mental health services, with high 
levels of dissociation. 
Sample Size 
12 (4 per study) 
Planned Study Period  Total study period: 6th March 2023 – 5th March 2024. 
Individual participant involvement: 12-15 weeks.  
Planned Recruitment 
Period  
6th March 2023 – 31st December 2023. 
 
 
Objectives 
Outcome 
Measures 
Timepoint(s)  
Primary 
 
To determine whether the psychological 
intervention reduces the psychological 
maintenance mechanism (factor) of 
interest (i.e. cognitive appraisals [study 1]; 
perseverative thinking [study 2]; affect 
intolerance [study 3]). 
Study 1: CAD-P 
Study 2: PTQ 
Study 3: AIS 
 
Daily rating 
(throughout baseline 
and intervention 
window), every other 
day (throughout 
follow-up window). 
Secondary 
To gain a preliminary indication of 
whether the relationship between the 
proposed psychological factor (cognitive 
appraisals; perseverative thinking; affect 
intolerance) and ‘felt sense of anomaly’-
type dissociation is causal. 
As above + 
ČEFSA-14 
As above. 
Qualitative 
To improve the therapy intervention for 
use in future treatment development 
studies. 
Qualitative 
feedback from 
participants. 
At one-month 
follow-up. 
Intervention 
 
Study 1 (cognitive appraisals): CBT techniques for cognitive reappraisal. 
Study 2 (perseverative thinking): Condensed form of Wells’ CBT intervention for worry 
(negative ruminative thinking). 
Study 3 (affect intolerance): ACT techniques for approaching and tolerating affect. 
Comparator  
Through the study design, the participants serve as their own comparator (baseline [A] 
versus therapy [B] phase), and random allocation of the length of the baseline (‘multiple 
baseline design’) allows each participant to be the comparator to the others in that study 
(testing that maturation is not the cause of any improvement seen in the B phase). 
 
 
 

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3. ABBREVIATIONS 
AE 
Adverse Event 
AIS 
Affect Intolerance Scale1 
AMHT 
Adult Mental Health Team 
CAD-P 
Cognitive Appraisals of Dissociation in Psychosis scale2 
CBT 
Cognitive Behavioural Therapy 
ČEFSA-14 
Černis Felt Sense of Anomaly Scale (Short Form) (Černis et al., in prep) 
CI 
Chief Investigator 
CRF 
Case Report Form 
DBT 
Dialectical Behavioural Therapy 
EIP 
Early Intervention in Psychosis 
FSA 
Felt Sense of Anomaly 
GCP 
Good Clinical Practice 
GDPR 
General Data Protection Regulation 
GSE 
General Self Efficacy scale3 
HRA 
Health Research Authority 
ICF 
Informed Consent Form 
ICMJE 
International Committee of Medical Journal Editors 
IP 
Intellectual property  
LEAP 
Lived Experience Advisory Panel 
MBD 
Multiple Baseline Design 
NHS 
National Health Service 
OAS 
Online Alexithymia Scale (amended)4 
PIS 
Participant/ Patient Information Sheet 
PTQ 
Perseverative Thinking Questionnaire5 
REC 
Research Ethics Committee 
RTD 
Responses to Dissociation scale4 
SAE 
Serious Adverse Event 
SCED 
Single Case Experimental Design 
UoB 
University of Birmingham 
VAS 
Visual Analogue Scale 
 
 

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4. BACKGROUND AND RATIONALE 
What is dissociation? 
“I was in a totally different world; it was going on all around me. I thought that I might have died and was in hell, and 
I was thinking maybe that's what it was.”  
 
 
 
 
-- “Maria” 
Dissociation involves confusing and upsetting feelings of unreality, unfamiliarity, or disconnection in 
relation to your mind, body, or surroundings6. For example, some people describe being detached from 
their own emotions, including affection for loved ones, or feeling profoundly ‘strange’, as though they 
are living life from behind a thick pane of glass. These experiences can cause significant distress6,7, and 
have been linked with risk of self-harm or suicide8–10, and with increased severity11 and incomplete 
treatment-response12 of comorbid mental health diagnoses. Many dissociative experiences considered 
transdiagnostic13,14. For example, dissociation is present at a very high rate in psychotic disorders 
(potentially up to 50%15). Crucially, in this context, it may even be instrumental in the development 
and maintenance of key psychotic symptoms, such as paranoid delusions and auditory hallucinations16. 
However, dissociation has traditionally been considered within the context of post-traumatic 
responses. As a result, a fuller understanding of dissociation as an independent construct – rather than 
simply as another post-traumatic symptom – has yet to be achieved. 
This ‘neglect’17, and extensive debate within the field18, has also resulted in a lack of clarity about the 
precise accepted definition of ‘dissociation’ as a construct19,20. Therefore, in previous work, we 
delineated a subgroup of common dissociative experiences unified by a core phenomenological 
experience of a ‘felt sense of anomaly’ (FSA)6,21. We will operationalise the term ‘dissociation’ within 
this project by focusing on this specific type of dissociative experiences (FSA-dissociation), since this 
has been demonstrated to be common and transdiagnostic22,23. 
What are the psychological maintenance mechanisms of dissociation? 
Understanding the psychological mechanisms of a pathological presentation is vital to developing an 
effective intervention for it. Seminal work developing (now gold standard) cognitive behavioural 
therapy (CBT) interventions for anxiety disorders24 and PTSD25 have demonstrated the clinical efficacy 
of identifying, verifying, and then precisely targeting the underlying causal mechanisms of the problem 
to be treated26. However, much remains unknown about the psychological mechanisms underpinning 
dissociation. To date, only two experimental studies inferring causality in dissociation have been carried 
out: one of which was by our group27,28. 
In our recent work, we began the process of identifying plausible mechanisms of FSA-dissociation4, 
resulting in a provisional cognitive model of the problem (Figure 1). This model suggests that 
dissociative experiences are maintained by a two feedback loops. The first is caused by catastrophic 
appraisals (negative interpretations or beliefs about the dissociative experience), which lead to 
rumination and counterproductive ‘safety behaviours’ (actions intended to mitigate potential harm), 
both of which serve to keep attention focused on the dissociation and reinforce interpretations of this 
experience as threatening. This first loop therefore proposes three possible maintenance mechanisms: 
catastrophic appraisals of dissociation, perseverative thinking (rumination), and counterproductive 
safety behaviours. 

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The second hypothesised feedback loop explains why the appraisals of dissociation are catastrophic in 
nature – as opposed to benign or benevolent. Across two large studies of online survey4 and NHS 
patient22 (psychosis) respondents, previous data has indicated relationships between dissociation and 
both high affect intolerance and low self-efficacy. In essence, people who feared shifts or peaks in their 
mood, and simultaneously felt powerless to manage or cope with challenges, were more likely to have 
FSA-dissociative experiences – as was indicated by previous qualitative evidence6. This second 
feedback loop therefore suggests two further plausible mechanisms of dissociation: affect intolerance 
and self-efficacy. 
In this project, we have chosen to focus on the three mechanisms with the largest effect sizes from 
this research: negative cognitive appraisals of the dissociative experience (causal effect 0.73 in a non-
clinical group4; 0.72 in a psychosis group22), perseverative thinking (rumination) (0.314; 0.5222), and 
affect intolerance (0.264; 0.4122). 
The current study 
The aim of this project is therefore to test the three largest psychological contributors to FSA-
dissociation as identified in this previous research: cognitive appraisals, rumination, and affect 
intolerance. Whilst there is evidence that these are all associated with dissociative experiences in the 
context of psychosis, to date there has been no experimental manipulation of these factors to 
demonstrate their role in maintaining dissociative difficulties. Evidence of their causal effect on 
dissociation is required before a translational psychological intervention can be developed.  
Using an interventionist-causal approach (experimentally manipulating the factor of interest via 
attempting to ameliorate it with therapeutic techniques) allows researchers to combine an experimental 
test of causal relationships with the first stages of treatment development. This project constitutes an 
intermediate stage along the trajectory of treatment development, in that the primary aim of these three 
studies will be to demonstrate proof-of-concept for the interventions, in order that a larger study with 
adequate statistical power to test for causal relationships and treatment efficacy may be carried out. 
 
 
 

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5. OBJECTIVES AND OUTCOME MEASURES 
The primary objective is to determine whether there is sufficient reason to believe that each 
psychological intervention targets (reduces) the psychological maintenance mechanism (factor) of 
interest in that study to justify running a larger study. For Study 1 the mechanism of interest will be 
negative cognitive appraisals of the dissociative experiences; in Study 2, perseverative negative thinking 
(rumination); and in Study 3, affect intolerance (aversion to the experience of one’s own emotions). 
Therefore, the key outcomes will be measures of these three psychological factors: cognitive appraisals 
of dissociation, perseverative thinking, and affect intolerance. 
Of relevance to future treatment development for dissociation, the secondary objective of this project 
is to gain a preliminary indication of the effect targeting the above mechanisms has on levels of 
dissociation – i.e. whether this relationship is causal. There will not be adequate statistical power in 
these studies to definitively answer this research question. However, data from this study may aid 
future research by providing initial estimates for sample size calculations. 
Since we are interested in further testing and developing the techniques in this project (if this is justified 
by the data), we will also ask participants for qualitative feedback about their experiences of the 
intervention and research processes at the end of their participation, and use the experience of running 
this study to inform which patient-facing logs, worksheets, and diaries may be most useful in 
developing a future intervention. 
These objectives and outcomes are summarised below: 
 
Objectives 
Outcome 
Measures 
Timepoint(s)  
Primary 
 
To determine whether the psychological 
intervention is likely to reduce the psychological 
maintenance mechanism (factor) of interest (i.e. 
cognitive appraisals [study 1]; perseverative 
thinking [study 2]; affect intolerance [study 3]). 
Study 1: CAD-P 
Study 2: PTQ 
Study 3: AIS 
 
VAS rating: daily 
(throughout baseline 
and intervention 
window), or every 
other day 
(throughout follow-
up window). 
 
Full measure rating: 
baseline, post-
intervention, one 
month follow-up. 
Secondary 
To gain a preliminary indication of whether the 
relationship between the proposed psychological 
factor (cognitive appraisals; perseverative 
thinking; affect intolerance) and ‘felt sense of 
anomaly’-type dissociation may be causal. 
As above + 
ČEFSA-14 
As above. 
Qualitative 
To improve the therapy intervention and 
research processes for use in future treatment 
development studies. 
Qualitative 
feedback from 
participants. 
Audit of which 
patient-facing 
therapeutic 
materials were 
used. 
At one-month 
follow-up (end of 
participation). 

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6. STUDY DESIGN 
This project consists of three randomised multiple baseline design (MBD) single case experimental 
design studies, with an A1B1A2 structure (Appendix A). 
Each study will have four participants. After completing a baseline assessment, each will be randomised 
to a different length of baseline (phase A1) duration (either 1, 2, 3 or 4 weeks). During A1, participants 
will rate the target maintenance mechanism (factor) and their level of dissociation daily (see Section 
9.6, Assessments). 
The treatment window (phase B1) for each participant in all studies will be five weeks. In this time, 
participants will have four 1:1 one-hour long psychological therapy sessions with a qualified clinical 
psychologist who will deliver the study intervention (see Section 10, Study Interventions). Between-
session tasks will be set as part of this intervention, to be completed by the participant alone, or with 
telephone or additional in-person support from the research team. Participants will continue to rate 
the maintenance mechanism factor and their dissociation every other day. At the end of the 
intervention window (phase B1), participants will repeat the baseline assessment measures in a ‘post-
intervention’ assessment. 
The follow-up phase – phase A2 – will last for one month following the closure of the intervention 
window (phase B1). In this phase, participants will continue to make ratings of the maintenance 
mechanism factor and their dissociation every other day. At the end of phase A2, participants will 
complete the baseline assessment measures again in a ‘follow-up’ assessment, and will be offered the 
chance to provide unstructured qualitative feedback about the research processes and intervention. 
This project will be registered with ClinicalTrials.gov. 
 
7. PARTICIPANT IDENTIFICATION 
7.1. Participants 
The target population is people attending NHS mental health services for an Axis I mental health 
difficulty who are also experiencing high levels of dissociation. Evidence indicates that such 
experiences are common across mental health diagnoses14. 
7.2. Inclusion Criteria 
• Aged between 16 years to 80 years; 
• Outpatient of mental health services (at the time of referral to the study); 
• Experiencing significant levels of ‘felt sense of anomaly’-type dissociation (defined as a score 
within the ‘moderate severe’ or ‘severe’ range on the ČEFSA-14 (i.e,, score of 39 or above); 
Černis et al., in prep.); 
• Want help to improve their dissociative experiences; 
• Willing and able to give consent for participation in the study; 
• Available to undertake the baseline assessment in the indicated week; 
• Available to undertake the therapy sessions within the indicated therapy ‘window’. 

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7.3. Exclusion Criteria 
The participant may not enter the study if ANY of the following apply: 
 
• Diagnosis of an Axis II (“personality”) disorder; 
• Primary diagnosis of alcohol/substance dependency, organic syndrome, or learning disability; 
• Presence of risk issues that would be a clinical priority above managing dissociative symptoms 
(e.g., moderate to severe self-harm; active suicidal behaviour; etc.); 
• Current engagement in any other individual psychological therapy (or psychological therapy 
due to begin within the participation window for this study). 
 
• A participant may also not enter the study if there is another factor (i.e., with higher clinical 
priority), which, in the judgement of the investigator, would preclude the participant from 
providing informed consent or from safely engaging with the study procedures. Reason for 
exclusion will be recorded in line with CONSORT 2010 Statement29. 
 
8. STUDY PROCEDURES 
 
The study flow chart is shown in Appendix A, and a schedule of procedures is summarised in Appendix 
B. 
After screening and consent, participants will have seven study visits: three assessments, and four 
therapy sessions. 
All participants will complete three assessment visits with a research assistant. The first is at baseline 
(0 weeks). The second, ‘post-intervention’ assessment, will occur as soon as practicable after the five-
week intervention window has closed (i.e., within the next working week). The exact timescale for the 
second assessment will therefore vary, since each participant will be randomly allocated to wait either 
one, two, three, or four weeks between the baseline (0 weeks) assessment and the start of the 
intervention (see diagram below). All ‘follow-up’ assessments will take place one-month after the 
participant’s post-intervention assessment. Additionally, all participants will complete a brief (two-
item) survey via telephone, text message, or online survey (via Qualtrics) daily throughout the pre-
intervention phase, and every other day during the intervention and follow-up phases; see Section 9.6 
‘Assessments’. 
 
A
Baseline Wait
Post
Follow up
B
Baseline Wait
Wait
Post
Follow up
C
Baseline Wait
Wait
Wait
Post
Follow up
D
Baseline Wait
Wait
Wait
Wait
Post
Follow up
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Key
assessment
no contact from study team
Diagram summarising the timeline of  visits for each individual study.
intervention window 
(x4 sessions within 5 weeks)
Intervention window
Intervention window
Intervention window
Intervention window
Participant
Week

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All participants will receive the intervention for that study (i.e., targeting cognitive appraisals [study 1]; 
perseverative thinking [study 2]; or affect intolerance [study 3]). Four 1:1 therapy sessions will take 
place within the five-week intervention window. This allows some flexibility for therapist and 
participant in the case of absence, illness, or other difficulty scheduling appointments. More detail is 
given in Section 10, ‘Study Interventions’. 
We will inform participants’ relevant clinical team that they are taking part in the study (e.g., via the 
clinical notes system, or feedback to the referring clinician). 
8.1. Recruitment 
The recruitment target is 12 participants (four participants in three studies). Recruitment will be 
conducted in two local NHS mental health trusts: Birmingham Women’s and Children’s NHS 
Foundation Trust, and Birmingham and Solihull NHS Foundation Trust. Participants will be recruited 
from the NHS services accessible to help-seeking people aged 16 and over. The services include 
specialist early intervention in psychosis services (EIP: ages over 14 years), and adult mental health 
teams (AMHTs), as well as Psychological Services. Support for the project has been established with 
the relevant clinical leads; notably within the early intervention in psychosis service (Forward Thinking 
Birmingham), and with the Lead for Psychological Therapies. 
The principal method of recruitment will be from routine clinical services. The clinical team or clinical 
research network (CRN) staff will identify potential referrals from the team caseload and provide 
potential participants with the participant information sheet (PIS). Additionally, the lead researcher for 
this study works within clinical services one day a week, and may therefore also identify referrals and 
approach patients as part of their clinical role. If participants confirm they are happy to be contacted 
by the research team their contact information will be passed on the research team for this purpose. 
The research team will make a note of the verbal consent in their contact records. If participants do 
not want their contact details passed on to researchers at this time, they may retain the PIS and contact 
the researchers themselves at a later stage. 
In a previous study with similar recruitment methods, the Lived Experience Advisory Panel (LEAP) 
for that trial emphasised the importance of patients also self-initiating referral to the study, in order to 
minimise the chances that particular patients are overlooked by clinical teams or the clinician was not 
present at a referral meeting. Therefore, we will also advertise the study (including via social media, 
online, posters present in NHS buildings, and other relevant sites). Hence, patients will be able to self-
refer to take part in the study. However, in all instances we will also seek to confirm that a member of 
their clinical team gives approval for a patient to enter the study. 
8.2. Screening and Eligibility Assessment 
The eligibility assessment will be conducted by a research assistant under the supervision of a qualified 
clinical psychologist. The screening will take place at either an NHS clinical base, University clinical 
research site, or the patient’s home, depending on their preference.   
The eligibility assessment will include confirmation of the key clinical problem and availability for 
participation including: 
• Self-report questionnaire assessing dissociation (ČEFSA-14; Černis et al., in prep. – based on 
the original ČEFSA21); 
 
• Confirming that the patient meets inclusion and exclusion criteria – particularly clinical 
assessment / confirmation of the clinical team’s assessment that there are no imminent risk 

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issues that would take clinical priority for treatment (see section 8.3 ‘Exclusion Criteria’); 
 
• 
Checking that the patient is available to participate according to the anticipated schedule of 
the study: i.e., that they would be able to undertake the baseline in the designated week, 
would be willing to commit to four sessions of therapy, are not anticipating extended 
absences during the weeks in which the intervention window may fall, and will not be 
commencing any psychological therapies within the study participation period.  
The above discussion and completion of the ČEFSA questionnaire will take place under informal verbal 
consent of the patient and implied consent through completion of the questionnaires on the understanding 
that the purpose of these activities are to determine the applicability of the research to the patient, thus 
minimising the risk of them beginning a burdensome research assessment under formal written consent only 
to discover that the study is irrelevant to them. The patient will be made aware that any discussion notes or 
questionnaire forms completed during the eligibility assessment will be securely destroyed once (in)eligibility 
has been determined and their contact details will be deleted at the end of the study. 
8.3. Informed Consent 
Written informed consent will be obtained by either the research worker (who will be sufficiently 
trained for this purpose) or a qualified clinical psychologist from the research team. This will be after 
the clinical team approval to approach the patient, provision of the participant information sheet to 
the patients, opportunities to ask questions and at least 24 hours to decide.  
Written or electronic versions of the Participant Information Sheet (PIS) and Informed Consent Form 
(ICF) will be presented to the participants detailing no less than: the exact nature of the study; what it 
will involve for the participant; the implications and constraints of the protocol; the known side effects 
and any risks involved in taking part. It will be clearly stated that the participant is free to withdraw 
from the study at any time for any reason without prejudice to future care, and with no obligation to 
give the reason for withdrawal. 
The participant will be allowed as much time as wished to consider the information, and the 
opportunity to question the Investigator, or other independent parties to decide whether they will 
participate in the study. Written informed consent will then be obtained by means of participant dated 
signature and dated signature of the person who presented and obtained the ICF. If completed 
electronically, typed signatures will suffice. Copies of the consent form will be retained in the researcher 
site file, provided to the participant, and uploaded to the participants’ electronic medical records. 
Young people aged 16-18 years can be considered competent to consent to research and therefore, no 
parental consent to participate in the project will be sought. A qualified clinical psychologist trained in 
assessing capacity will assess the potential participant’s competence to consent to research if they are 
aged 16 or 17 years. If aged 18 years or above, capacity to consent will be assessed by a GCP-trained 
research assistant, with further assessment by the clinical psychologist in cases where capacity is 
unclear.  
8.4. Randomisation 
Randomisation will be carried out by a researcher outside of the study team. They will randomly 
allocate a baseline phase duration (one, two, three, or four weeks30) to a letter (A, B, C or D). This will 
be repeated for each of the three studies. Allocations will be recorded via the use of sealed envelopes, 
which will be stored securely by the CI. At each baseline assessment appointment, after the measures 
have been completed, the research assistant will select envelope A for the first participant, B for the 
second, and so on, and open the envelope to reveal to the participant how long their randomly-
allocated baseline phase will be. This will then be recorded in the baseline CRF and communicated to 
the therapist. 

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8.5. Blinding and code-breaking 
This study does not involve blinding. However, to incorporate a degree of impartiality, assessments 
will be carried out by a research assistant, not the therapist. 
8.6. Assessments  
All participants will undertake the baseline assessment in the same week, following a concurrent 
randomised multiple-baseline study design. Participants will undertake three assessment visits with the 
research assistant (these are referred to in SCED terminology as ‘standard’ assessments), and frequent 
ratings of the two primary constructs between assessments, throughout the course of the study (these 
are referred to as ‘target’ assessments)31. All assessments will use a study ID in place of identifying 
information. 
 
9.6.1  ‘Standard’ Assessments 
The baseline, post-intervention, and follow-up assessments will each last approximately 50 minutes. 
The assessment will be conducted at an NHS or University of Birmingham building, or the participant’s 
home, based on participant preference. The assessment will be conducted on an individual basis, with 
only the participant and researcher present. Assessments can be conducted remotely (for example using 
telephone, online, or postal versions) if necessary. Online assessments may be in the form of either: 
the participant annotating an electronic (Word document) version of the measures; the RA annotating 
a hardcopy or electronic copy of the measures whilst on a call with the participant; or via Qualtrics. 
Self-addressed stamped envelopes will be provided for participants returning measures by post, in the 
case that it is not practicable for the RA to collect these in person to ensure safe receipt. 
All assessments in the study are self-report measures; except for the recording of the participant’s 
clinical diagnosis and current prescribed medication, which will be extracted from their clinical records 
at each assessment point. Permission to access clinical records for this purpose will be obtained during 
the informed consent process. 
The self-report outcomes collected at all three standard assessments are: 
1. ‘Felt sense of anomaly’ (FSA)-type dissociative symptoms: 
• 
Černis Felt Sense of Anomaly scale – revised (ČEFSA-14; Černis et al., in prep. – based on the 
original ČEFSA21) 
• 
Visual analogue scale (VAS) rating 0-100 for FSA-dissociation. 
2. Possible mechanisms of FSA-type dissociation: 
• 
Cognitive Appraisals of Dissociation in Psychosis scale (CAD-P2); 
• 
Perseverative Thinking Questionnaire (PTQ5); 
• 
Affect Intolerance Scale (AIS1); 
• 
Online Alexithymia Scale (amended) (OAS4); 
• 
General Self Efficacy scale (GSE3); 
• 
Responses to Dissociation scale (RTD4). 
• 
VAS rating (0-100) for the study-specific mechanism of interest (i.e., cognitive appraisals 
[study 1]; perseverative thinking [study 2]; affect intolerance [study 3]). 
3. Self-harm: 

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• 
One item asking the frequency of recent self-harming behaviours. A full validated measure of 
self-harm and suicidality is not included as this study is not powered to establish clinical 
effect, but nevertheless, this rough indicator will provide helpful insight for future studies as 
it has been suggested that self-harm may also act as a mechanism or trigger for dissociative 
experiences8. 
Additionally, at the baseline assessment (only), basic demographics (age, gender, ethnicity) will be 
collected, and a brief summary of the participant’s previous experience receiving psychological 
therapy. 
9.6.2  ‘Target’ Assessments 
Between standard assessments, participants will be asked to complete two visual analogue scales (VAS) 
either daily (during the baseline (A1) phase), or every other day (during the intervention (B1) and follow-
up (A2) phases). These will ask the participant to rate from 0 to 100: 1) the severity of the distress 
caused by dissociation since the last rating, and 2) how much they have been bothered by the study-
specific psychological factor (i.e., cognitive appraisals [study 1]; perseverative thinking [study 2]; affect 
intolerance [study 3]) since the last rating. 
 
To help participants remember to complete these measures, and to reduce participant burden, 
participants will decide with the research assistant the most convenient way for them to complete the 
scales (e.g. via telephone call, text message, completion of an online survey link sent via email or text, 
or taking home a supply of paper copies), and how they would like the researcher to remind them to 
complete these (e.g., a daily text, automated emails, or a call once a week). Responses received via text 
will be transferred and stored on UoB servers as per UoB IT guidance. 
 
9.6.3  Qualitative Feedback 
At the end of the follow-up assessment (only), participants will be given the opportunity to provide 
qualitative feedback regarding the study procedures and therapy. This is voluntary. If a participant 
does choose to give feedback, they will be given the option of providing written or audio-recorded 
feedback (consent for audio recording capture, storage, and transcription will be covered in the ICF 
for the study) in the follow-up assessment appointment.  
Additionally, all participants will be given a link to an anonymous online ‘comments box’ (online 
survey text box on Qualtrics) in case they wish to give feedback after the appointment, or do not feel 
comfortable giving feedback to the research assistant directly.  
The feedback will take an unstructured form, with no topic guide or interview schedule – except that 
participants will be prompted to provide feedback on ‘how you found both the study process, and 
how you found the therapy’, and that ‘we are interested in negative feedback as well as positive, so 
that we can learn how to improve the experience for future participants’. 
If feedback is given verbally, it will be audio-recorded and transcribed verbatim. All feedback will be 
analysed using Thematic Analysis32. Quality guidelines33 will be followed, including credibility checks 
and reflexive practice. This approach has been used before by the CI with a similar participant group6. 
8.7. Early Discontinuation/Withdrawal of Participants  
During the course of the study, a participant may choose to withdraw early from the study at any time. 
This may happen for several reasons, including but not limited to: 
• The occurrence of what the participant perceives as an intolerable AE.   

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• Inability to comply with study procedures  
• Participant decision  
 
Participants may choose to stop treatment and/or study assessments but may remain on study follow-
up. Participants may also withdraw their consent, meaning that they wish to withdraw from the study 
completely. Withdrawal from the study or intervention will not affect their usual care.  
According to the design of the study, participants may have the following two options for withdrawal;  
 
1) Participants may withdraw from active follow-up and further communication but permit data 
obtained up until the point of withdrawal to be retained for use in the study analysis.  No 
further data would be collected after withdrawal.   
 
2) Participants can withdraw completely from the study and withdraw the data collected up until 
the point of withdrawal. The data already collected would not be used in the final study 
analysis, unless analysis has already begun/been completed.  
 
In addition, the Investigator may discontinue a participant from the intervention at any time if the 
Investigator considers it necessary for any reason including: 
• Ineligibility (either arising during the study or retrospectively having been overlooked at 
screening); 
• An adverse event which requires discontinuation of the intervention; 
• Clinical decision. 
If the participant is withdrawn due to an adverse event, the Investigator will arrange for follow-up 
visits or telephone calls until the adverse event has resolved or stabilised. 
The reason for withdrawal will be recorded in the CRF. 
8.8. Definition of End of Trial 
The end of study is the date of the last study contact. 
 
9. STUDY INTERVENTIONS  
In each of the three studies, participants will be offered four one-hour sessions of individual therapy 
with a qualified clinical psychologist with expertise in dissociative difficulties. These will take place 
within the five-week intervention window, and will be held at an NHS or University of Birmingham 
site, or the participant’s home, according to their preference. 
Each intervention will target the putative maintenance mechanism of interest for that study (see 
below). In each study, the first session will also include socialisation to the therapy session format and 
psychoeducation about how the mechanism might relate to dissociative experiences. Sessions 1 to 3 
will involve learning and practicing active change techniques, whilst the final session will focus on 
consolidation of new information, planning for the future, and managing the therapeutic ending.  
Practice of techniques between sessions will be encouraged, and may be supported by additional 
between-session contact (e.g. text messages, telephone calls, or meetings to carry out behavioural 
experiments in a supported manner) with an assistant (graduate-level) psychologist where indicated. 

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This therapy will be provided in addition to usual care. The quality of the therapy will be checked by 
the independent rating of audio-recordings of sessions by the therapist’s clinical supervisor. Audio-
recording of therapy sessions is optional – permission will be sought from participants at each session, 
and verbal consent confirmed at the start of the recording. Each time, participants will be reminded 
that they may request the recording to stop and/or be deleted at any time. To enable reporting of 
treatment delivery and fidelity, details such as the date, duration, and key discussion topics of each 
session will be recorded by the therapist for each session. All missed or cancelled therapy appointments 
will be recorded. 
As noted above (6. Objectives And Outcome Measures), one of the aims of the study is to understand 
which therapy materials may be most helpful for future treatment development. Therefore, the details 
below – particularly with respect to administration of patient-facing materials – are preliminary and 
subject to personalisation for each participant as appropriate. Full details of this personalisation will be 
recorded and reported. 
9.1.  Study 1 – Negative Cognitive Appraisals of Dissociative Experiences 
The key therapeutic technique delivered in this intervention will be cognitive restructuring, drawn from 
classical cognitive-behavioural therapy (e.g.34).  
Participants will be supported to understand what cognitive appraisals are, learn to notice and record 
these using a cognitive appraisals log/diary, and then supported to use an extended log/diary to 
challenge and adjust any negative assumptions contained within these. The aim is for participants to 
become more aware of the automatic appraisals they are making of their dissociative experiences and 
replace these with more balanced judgements. 
There is extensive evidence for the use of this technique across the full range of mental health 
presentations, particularly in depression and anxiety, but also in a dissociative diagnosis: 
depersonalisation disorder35. 
9.2.  Study 2 – Perseverative Thinking (Rumination) 
The key therapeutic techniques delivered in this intervention will be those used effectively in a four-
session worry intervention for persecutory delusions36. 
Participants will be supported to consider their positive and negative beliefs about worry, identify their 
typical triggers for worry, and learn and practice problem-solving and worry-management techniques. 
This therapy has been thoroughly tested in the context of psychosis36–38 and demonstrated to be 
effective in reducing worry, as well as the downstream effect of worry in this context: paranoia. It is 
therefore anticipated to have a similar effect in the context of dissociation. 
9.3.  Study 3 – Affect (Emotion) Intolerance 
The key therapeutic techniques delivered in this study will be drawn from CBT and dialectical 
behavioural therapy (DBT). 
Participants will be supported to explore their own beliefs about emotions (CBT) and learn why affect 
is necessary and adaptive for daily life (DBT). They will work with the therapist to identify their 
individual triggers for affect intolerance (CBT/DBT) and respond to these in the most relevant way, 

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including: learning and practicing DBT coping strategies; carrying out behaviour experiments to test 
their assumptions/beliefs (CBT); or carrying out cognitive restructuring to balance beliefs/appraisals 
(using the same techniques as in Section 10.1, Study 1; CBT). 
These techniques have been used effectively in the treatment of emotion dysregulation and affect 
intolerance39. They are therefore anticipated to have a similar effect in the context of dissociation. 
 
10. SAFETY REPORTING 
Adverse events are rare in these kinds of studies. Adverse events are likely to come to the attention 
of the assessor or therapist, but all medical notes will be systematically checked for serious adverse 
events following completion of the final assessment to ensure all adverse events are recorded. The 
responsible clinical team will be informed of any adverse event. The responses to an adverse event 
will be determined on a case-by-case basis. The University of Birmingham Quality Management 
System procedures for safety reporting will be followed. 
10.1.  
Definition of Serious Adverse Events 
A serious adverse event is any untoward medical occurrence that: 
• results in death 
• is life-threatening 
• requires inpatient hospitalisation or prolongation of existing hospitalisation 
• results in persistent or significant disability/incapacity 
 
Other ‘important medical events’ may also be considered a serious adverse event when, based upon 
appropriate medical judgement, the event may jeopardise the participant and may require medical or 
surgical intervention to prevent one of the outcomes listed above. 
Formal complaints regarding therapy or research procedures will also be recorded. 
10.2. 
       Reporting Procedures for Serious Adverse Events 
All serious adverse events that come to our attention are reviewed by the study team. These include 
serious events which are:  
• Related to the intervention/study procedure related or not;  
• Anticipated and unanticipated serious events;   
A serious adverse event (SAE) occurring to a participant should be reported to the REC that gave a 
favourable opinion of the study where in the opinion of the Chief Investigator the event was ‘related’ 
(resulted from administration of any of the research procedures) and ‘unexpected’ in relation to those 
procedures. Reports of related and unexpected SAEs should be submitted within 15 working days of 
the Chief Investigator becoming aware of the event, using the HRA report of serious adverse event 
form (see HRA website). 
The study team will make an initial assessment of whether the SAE is potentially related to the study 
procedures or intervention and report to the regulatory authorities within the appropriate timescales. 

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10.3. 
  Events exempt from immediate reporting as SAEs  
Hospitalisation for a pre-existing physical health condition, including elective procedures planned prior 
to study entry, which has not worsened, does not constitute a serious adverse event.  
 
11. DATA ANALYSIS 
The statistical aspects of the project are summarised here, and will follow the procedures 
recommended for this study design40.  
11.1. Statistical Analysis 
Given the design and sample size, analysis will be descriptive in nature and no hypothesis testing will 
be carried out. The three studies will be analysed separately according to the following analysis plan. 
 
12.1.1 Quantitative data 
First, patient outcome measures will be presented graphically, and visual and statistical analysis used 
to assess within- and between-phase data patterns, as per the recommendations for SCEDs40. 
 
• Within-phase analysis:  
o level (mean and standard deviation and/or median and interquartile range);  
o trend (visual analysis or whether datapoints are increasing / decreasing); 
o stability (whether 80-90% of datapoints fall within 15% of the mean or median40). 
 
• Between-phase analysis: 
o Immediacy of effect (visual analysis); 
o Consistency of data patterns (visual analysis; trend analysis); 
o Overlap between phases (nonoverlap statistics e.g. extended celeration line or two 
standard deviation band method; as appropriate40). 
 
The above information will be used to form a judgement as to whether the data indicates that the 
intervention is causing a change in outcome measure scores. If so, effect sizes (Tau-U41) will be 
calculated. 
 
12.1.2 Qualitative data 
Written and transcribed qualitative data arising from requests for feedback on the research process and 
therapy intervention (see Section 9.6.3, Qualitative Feedback) will be analysed using Thematic Analysis32. 
This analysis will be managed within qualitative analysis software. Quality guidelines33 will be followed, 
including credibility checks and reflexive practice. This approach has been used before by the CI with 
a similar participant group6. Key themes arising from this analysis will be reported within the study 
results. 
11.2. Sample Size Determination 
The aim of SCED studies is to use repeated phases with and without the application of the 
experimental intervention to demonstrate that it is the intervention that is causing the observed effect. 
In essence, this allows the same participant to contribute both control and intervention data, increasing 
information about probable cause and effect in contexts where it may not be feasible to run a fully 
powered randomised controlled trial31. General convention suggests that demonstrating changes in the 
outcome measure after introducing or withdrawing the intervention must be done a minimum of four 

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times to imply a functional relationship between intervention and effect40. Typically, this can be 
achieved by repeatedly introducing and withdrawing an intervention with the same participant. 
However, this method is less valid in clinical psychology, where carry-over effects are expected from 
the intervention, and repeating the intervention may not be practicable. Thus, the multiple-baseline 
design (MBD) across individuals allows the requisite number of transitions (from intervention to ‘no 
intervention’ and vice versa) to be achieved, whilst each participant only undergoes the treatment once. 
Randomising the length of the baseline phase for each participant means that any observed effect 
cannot be better understood as a function of time elapsed since the baseline assessment or other 
research procedure. The minimum number of participants required for an MBD study is two, although 
three or more is typical42. Thus, this project will use a sample size of four participants per study, to 
mitigate against any potential drop out or high levels of missing data. 
11.3. Analysis Populations  
All participants recruited to the study will be documented fully with respect to receiving the 
intervention and participating in follow up. Adverse events will be reported for all participants.   
11.4. Decision points and stopping rules 
There are no interim analyses or formal stopping rules in relation to this study given the small sample 
size and its exploratory nature. 
11.5. The Level of Statistical Significance 
This is not applicable: no significance testing will be undertaken given the small sample size and 
exploratory nature of the study. 
11.6. Procedure for Accounting for Missing, Unused, and Spurious Data. 
There will be no statistical methods applied for handling missing data as this approach is inconsistent 
with the single experimental case design. For each participant, phases with fewer than five datapoints 
will be omitted from analysis, since this is the minimum recommended for within-phase analyses40. 
 
12. DATA MANAGEMENT 
 
The plan for the data management of the study is outlined below. There is not a separate Data 
Management document in use.  
12.1.  
Source Data 
Source documents are where data are first recorded, and from which participants’ CRF data are 
obtained. These include, but are not limited to, hospital records (from which current diagnosis and 
medication levels may be extracted to record in the CRF), and study assessment measures. 
All documents will be stored safely in confidential conditions. On all study-specific documents, other 
than the signed consent, the participant will be referred to by a participant number/code, not by name. 
12.2. 
Access to Data 
Direct access will be granted to authorised representatives from the Sponsor, host institution and the 
regulatory authorities to permit study-related monitoring, audits and inspections. 

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12.3. 
Data Recording and Record Keeping 
All study data will be entered on paper or electronic CRFs and transcribed or entered directly to the 
clinical data management system. Data will be anonymised using a unique study ID. Personal data and 
participant identification codes will be kept separately from the research data. Access to these data will 
be strictly on a need-to-know basis. Any secure data transfer will take place in accordance with 
University of Birmingham policies. 
Data will be entered from paper CRFs to the clinical database, or recorded directly on eCRFs as soon 
as possible after the study visit. Validation of all data entered into the clinical database is achieved 
through manual review. All critical data items are 100% checked against original source documents, 
where applicable, to ensure accuracy and an error rate is established across all fields to ensure a 
consistently accurate dataset. 
Audio recordings of therapy sessions and feedback will be taken using a password-protected recording 
device. They will be immediately deleted from the device once they are transferred onto a secure 
university server. Recordings should be transferred and deleted from the device within one working 
day of the appointment in which they were made.  
Recordings of therapy sessions will be used for the purposes of clinical supervision and treatment 
development only. These will be downloaded, encrypted, and stored on a secure server. Only a 
qualified clinical psychologist will have access to this data for the sole purpose of ensuring the quality 
of the therapy. All audio-recordings will be deleted one year after the end of the study. 
Recordings of qualitative feedback will be transcribed by the research team.  Transcriptions will be de-
identified, and audio files will be deleted after the transcripts have been checked for accuracy by a 
second researcher. Transcripts will be used along with written qualitative feedback as outlined in 
section 12, ‘Data Analysis’. 
Electronic data will be kept on a secure University of Birmingham server. Hard copy of data will be 
kept in a locked filing cabinet in a locked University of Birmingham office.  
The report of the study will not identify any individuals. Data will be kept for 10 years following 
publication of the results. 
 
13. QUALITY ASSURANCE PROCEDURES 
13.1.  
Risk assessment and monitoring 
The study will be conducted in accordance with the current approved protocol, GCP, relevant 
regulations and standard operating procedures. Data will be evaluated for compliance with the 
protocol, standard operating procedures, GCP, and accuracy in relation to source documents. All 
electronic data entry is double checked against the source documents. 
13.2. 
Trial committees 
Given the small size of the project, there will be no trial steering committee or Data Monitoring and 
Ethics Committee. Instead, the functions of a trial management group will be performed by the CI, 
who has extensive clinical trials experience. 
 

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14. PROTOCOL DEVIATIONS  
 
A trial related deviation is a departure from the ethically approved study protocol or other study 
document or process (e.g., consent process or administration of study intervention) or from Good 
Clinical Practice (GCP) or any applicable regulatory requirements. Any deviations from the protocol 
will be documented in a protocol deviation form and filed in the study master file. 
 
15. SERIOUS BREACHES 
 
A serious breach is defined as “A breach of GCP or the trial protocol which is likely to affect to a 
significant degree –  
(a) the safety or physical or mental integrity of the subjects of the trial; or 
(b) the scientific value of the trial”. 
In the event that a serious breach is suspected the Sponsor must be contacted within 1 working day. 
In collaboration with the CI, the serious breach will be reviewed by the Sponsor and, if appropriate, 
the Sponsor will report it to the REC committee, regulatory authority, and the relevant NHS host 
organisation within seven calendar days. 
 
16. ETHICAL AND REGULATORY CONSIDERATIONS 
16.1. 
  Declaration of Helsinki 
The Investigator will ensure that this study is conducted in accordance with the principles of the 
Declaration of Helsinki. 
16.2. 
Guidelines for Good Clinical Practice 
The Investigator will ensure that this study is conducted in accordance with relevant regulations and 
with Good Clinical Practice. 
16.3. 
Approvals 
Following Sponsor approval, the protocol, informed consent form, participant information sheet will 
be submitted to an appropriate Research Ethics Committee (REC), HRA (where required), and host 
institution(s) for written approval. 
The Investigator will submit and, where necessary, obtain approval from the above parties for all 
substantial amendments to the original approved documents. 
Both substantial and non-substantial amendments will be submitted to the sponsor for review and 
approval prior to submission to the relevant regulatory authorities. 
16.4. 
Other Ethical Considerations 
We anticipate few ethical concerns for patients entering this study. The study will be conducted by a 
CI who is a qualified clinical psychologist with extensive experience of clinical trials, and who has 

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appropriate training regarding the management of any risk or safeguarding issues that may arise during 
the course of the study. There is a risk that safeguarding concerns are raised (e.g. identification of risk 
of self-harm etc.). These will be reported as soon as possible to the direct care team, and the participant 
supported appropriately within the boundaries of the trial (e.g. signposted to Samaritans, reminded of 
existing risk-management plan, etc.).”Participation in the study does not change existing treatment 
receipt, so there is no disadvantage in taking part. Participants will be free to discontinue the study at 
any point, without needing to give an explanation. 
The main potential problem is the burden of assessments (three visits and daily/alternate-day reporting 
for two key items); however, most trials with similar patient groups show a modest symptom benefit 
of entering the control condition in a therapy trial, most likely due to the additional monitoring and 
sensitive manner of the research assessors (e.g.43). We offer payment for participants’ time and 
flexibility in the assessments, such as providing breaks, or arranging for these to take place at a location 
of participants’ choice – including online. The study questionnaires ask participants about their mental 
health, which may be considered a sensitive topic. However, these are issues participants are already 
managing outside of the study, and they will have experience of talking about them as part of the 
treatment they are receiving from NHS services. Research assistants are trained to ask questions 
sensitively and participants are informed that they do not have to answer any questions if they do not 
want to. 
The therapy consists of techniques that have been delivered previously in clinical practice and research 
trials without adverse events in other clinical groups. Although the techniques have not yet been 
applied to a high dissociation group, the CI’s clinical practice has given no indication that the 
techniques would be inappropriate for this specific group, nor are they expected to cause any undue 
upset or distress beyond that which could be expected in psychological therapy. During the 
intervention, participants will be invited to consider alternative actions and patterns of thinking to 
assist them in overcoming their difficulties. The pace of therapy is dictated by the participant and the 
intervention is a collaboration between the therapist and the patient. 
Safety of researchers is very important; therefore, we follow the NHS Trust’s standard operating 
procedure for lone working.  
16.5. 
Reporting 
The CI shall submit a Progress Report to the REC,, host organisation, funder, and/or Sponsor on an 
annual basis.  In addition, an End of Trial notification and final report will be submitted to the same 
parties. 
16.6. 
Participant Confidentiality 
The study will comply with the General Data Protection Regulation (GDPR) and Data Protection Act 
2018, which require data to be de-identified as soon as it is practical to do so. The processing of the 
personal data of participants will be minimised by making use of a unique participant study number 
only on all study documents and any electronic databases. All documents will be stored securely and 
only accessible by study staff and authorised personnel. The study staff will safeguard the privacy of 
participants’ personal data. 
16.7. 
Expenses and Benefits 
Reimbursement of participants, including payment for their time at research assessments and travel, 
are calculated following guidance from the McPin Foundation and INVOLVE guidelines.  
 

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Participants will be compensated £15 for their time for each research assessment in the study (a total 
of £45). Additionally, for each of the three phases (baseline/A1, intervention/B1, follow-up/A2), 
participants will be offered a further £15 if they complete five or more VAS ratings in that phase. 
Therefore, participants may be compensated a maximum total of £90 across the study. 
 
Reasonable travel expenses for any visits additional to normal care (including parking costs) will be 
reimbursed on production of receipts, or a mileage allowance provided as appropriate. Where 
receipts are not readily available, for example parking fees, the requirement to provide these before 
payment will be waived. 
 
17. FINANCE AND INSURANCE 
17.1. Funding 
The study is funded by a research allowance allocated to Dr Emma Černis by the School of Psychology, 
University of Birmingham. 
17.2. 
Insurance 
The University has in force a Public Liability Policy and/or Clinical Trials policy which provides cover 
for claims for "negligent harm" and the activities here are included within that coverage. 
17.3. 
Contractual arrangements  
Appropriate contractual arrangements will be put in place with any third parties involved in the project. 
 
18. PUBLICATION POLICY 
 
The Investigators will be involved in reviewing drafts of the manuscripts, abstracts, press releases and 
any other publications arising from the study. The role of the funder will be acknowledged in all 
publications. Authorship will be determined in accordance with the ICMJE guidelines and other 
contributors will be acknowledged. All participants will be offered a copy of the results. Specific 
consent to use de-identified participant quotes will be sought prior to publication. Reporting of the 
study will follow the Single-Case Reporting Guideline In Behavioural Interventions (SCRIBE) 
recommendations44. 
 
19. DEVELOPMENT OF A NEW PRODUCT/ PROCESS OR THE GENERATION OF 
INTELLECTUAL PROPERTY  
 
Ownership of IP generated by employees of the University vests in the University.  The protection 
and exploitation of any new IP is managed by the University’s technology transfer office. 
 
20. ARCHIVING 

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Archiving will be completed after publication of the study outcomes. Data will be stored securely at 
the University of Birmingham for 10 years post publication.   
 
 
 

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2. 
Černis E, Bird JC, Molodynski A, Ehlers A, Freeman D. Cognitive appraisals of dissociation in 
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Schwarzer R, Jerusalem M. General Self-Efficacy Scale. Published online January 9, 2012. 
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4. 
Černis E, Ehlers A, Freeman D. Psychological mechanisms connected to dissociation: Generating 
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Psychiatr 
Res. 
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doi:10.1016/j.jpsychires.2022.01.049 
5. 
Ehring T, Zetsche U, Weidacker K, Wahl K, Schönfeld S, Ehlers A. The Perseverative Thinking 
Questionnaire (PTQ): Validation of a content-independent measure of repetitive negative thinking. J 
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Page 28 of 31 
22. APPENDIX A:  STUDY FLOW CHART 
 
 

Date and version no.: version 3 – 04/12/23 
Page 29 of 31 
23. APPENDIX B:  SCHEDULE OF PROCEDURES 
 
Procedures 
Screening 
Baseline 
(0 weeks) 
assessment 
Baseline 
phase (A1) 
(1, 2, 3 or 4 
weeks) 
Intervention 
window (B1) 
(5 weeks) 
Post-
therapy 
Assessment 
Follow-up 
phase (A2) 
(1 month) 
Follow-up 
Assessment 
Study procedures 
Eligibility assessment 
X 
 
 
 
 
 
 
Informed consent 
 
X 
 
 
 
 
 
Randomisation 
 
X 
 
 
 
 
 
Adverse event monitoring 
X 
X 
X 
X 
X 
X 
X 
Data collection 
Demographics 
 
X 
 
 
 
 
 
Diagnosis and medication 
(from clinical records) 
 
X 
 
 
X 
 
X 
Measure of FSA-
dissociation (ČEFSA-14) 
 
X 
 
 
X 
 
X 
Measures of feasible 
maintenance mechanisms 
(CAD-P; PTQ; AIS; OAS; 
GSE; RTD) 
 
X 
 
 
X 
 
X 
Self-harm 
 
X 
 
 
X 
 
X 
VAS scales (dissociation; 
study-specific mechanism) 
 
X 
X* 
X** 
X 
X** 
X 
Qualitative feedback 
regarding therapy and study 
 
 
 
 
 
 
X 
Interventions 
NHS treatment as usual 
X 
X 
X 
X 
X 
X 
X 
Study intervention  
(4 sessions) 
 
 
 
X 
 
 
 
 
Key: * = daily; ** = every other day 
 
 

Date and version no.: version 3 – 04/12/23 
Page 30 of 31 
24. APPENDIX C:  AMENDMENT HISTORY 
 
Amendment 
No. 
Protocol 
Version 
No. 
Date 
issued 
Author(s) of 
changes 
Details of Changes made 
NSA01 
1.2 
31-08-2023 
Emma Černis 
Amended 
pre-registration 
location 
from ISRCTN to ClinicalTrials.gov 
NSA02 
2.0 
07-09-2023 
Emma Černis 
Amended entry criterion for ČEFSA-14 
scale to include ‘moderately severe’ as 
well as ‘severe’, and clarified that this 
corresponds to a score of 39 or more. 
SA001 
3.0 
04-12-2023 Emma Černis 
Amended recruitment source from 
psychology waiting lists (only) to 
team caseloads. 
 
 
 
 
 
 
List details of all protocol amendments here whenever a new version of the protocol is produced.  
Protocol amendments must be submitted to the Sponsor for approval prior to submission to the REC committee, HRA 
(where required) or MHRA.