Adapting and Evaluating Dialectical Behaviour Group Therapy for Adults With Dual Diagnosis (Intellectual Disabilities With Psychiatric Disorder)
Phase: NA
Conditions: Intellectual Disability
Sponsor: Dr. Jessica Jones

PSIY-511-15: Adapting and Evaluating Dialectical Behaviour Group Therapy 
for Adults with Dual Diagnosis (Intellectual Disabilities with Psychiatric 
Disorder) 
 
NCT02919826 
 
4 Dec 2017 
 

 
 
 
       Study Protocol & Statistical Analysis 
Present study 
 
The present study is a pilot community-based, double blind, randomized controlled trial 
of an adapted DBT skills group and program for individuals with Intellectual and Developmental 
Disabilities (IDD) and psychiatric illness. The purpose of this study was to clinically evaluate 
and empirically determine the feasibility and effectiveness of delivering an adapted DBT 
community-based skills group to adults with intellectual disability and transdiagnoses. Dykstra 
and Charlton’s work, Dialectical Behavior Therapy Skills Training: Adapted for Special 
Populations (DBT-SP; written in 2004 and revised in 2008; Dykstra & Charlton, 2008, Charlton 
& Dystra, 2011), was the basis from which the adapted DBT manual and program (i.e. aDBT-
ID) was used in the present study. As part of a community based DBT program, in addition to 
the manualized skills group, other components included mental health treatment i.e. psychiatric 
medication and consultation, individual therapy, crisis services, caregiver coaching and team 
consultation for both the researchers and clinicians.  
 
Methods 
 
Participants 
 
A community based sample of 19 adults with mild to moderate IDD and transdiagnoses 
i.e. co-morbid psychiatric disorders participated in the present study. Inclusion criteria were: age 
18-65 years old, administratively confirmed diagnosis of mild to moderate IDD, co-morbid 
psychiatric diagnoses and history of emotional and behavioural concerns and lead agency 
commitment i.e. allocated caregiver to attend all sessions. Exclusion criteria included a diagnosis 
of autism spectrum disorder or acute psychosis interfering with daily functioning.  
 
The group participants comprised of 9 males and 10 females; ages ranging from 22 to 34 
with one 52 year old. All were referred with confirmed diagnoses of mild (16) to moderate (3) 
IDD established by their administrative eligibility for support services i.e. DSM-V criteria for 
IDD. All lived in either residential treatment homes (3), group homes (5), host family home (2) 
or independent living either alone (4) with a roommate (2), with their parents (2) or a spouse (1).  
 
Co-morbid psychiatric diagnoses upon referral (not mutually exclusive) included 
Personality Disorders (BPD 10, Mixed PD 2), Mood Disorders (Depression 2, Anxiety 8, Bi-
Polar 3, OCD 2), Psychotic Disorders (2), Childhood Disorders (ADHD/ADD 7), Trauma 
Disorders (PTSD 4), Substance Abuse Disorder (1), Sexually Problematic Behaviour/Pedophilia 
(2), Acquired Brain Injury (1), Seizure Disorder (2) and Speech and Language Disorder (1). All 
participants were identified as having significant problems with emotional dysregulation and 
chronic interpersonal difficulties with family, friends and caregivers. In addition, the majority 

were experiencing behavioural difficulties with anger that impacted their daily functioning. All 
participants had a medication regime including a range of psychotropic medications for 
behavioural control and mental health stability (e.g. anti-psychotics, anti-depressants, anti-
anxiety, mood stabilizers) and treatments for associated physical health conditions (anti-
convulsants, diabetes medication).  
 
Clinical services outside of the group included psychiatric medication oversight for all 
participants except four who had family physicians prescribing. All participants had regular 
therapy or treatment interventions with either assigned social workers, psychologists, behaviour 
therapists, nurse or addiction counsellors. Also, participants had a variety of tertiary care team 
involvement including specialization in either dual diagnosis, mental health crisis, assertive 
community treatment and 24 hour access to mental health crisis lines. Some participants had 
regular legal oversight from either court diversion workers or probation officers. 
  
A total of 22 caregivers participated in the group trial, with n=14 completing 
assessments. Caregiver participants were comprised of both men and women from a range of 
developmental and mental health agencies. Majority were front line staff or direct support 
workers (14) apart from two behaviour therapists, two social workers and two family members. 
One participant had two workers attend due to his need for supervision. Most of the caregivers 
had known the clients for less than three years (15), with three knowing their clients between 3-
10 years and one for over 10 years. The amount of client contact ranged from 1-3 days a week 
(8) to 3-7 days a week (7) to bi-weekly or monthly (4). The duration of each contact ranged from 
intermittent daily contact (9), to 2-3 hours contact (6) to one-to-one counselling (4). The latter 
proportions likely influenced by living situation (e.g. group homes, host family and independent 
living) and type of contact (e.g. direct support hours, consultation services or therapy sessions.) 
 
.  
Procedure 
 
Following ethical approval, clients and caregivers were recruited through partnering 
developmental and mental health agencies that provide support services to persons with IDD, 
and through expression of previous interest by affiliated mental health professionals. 
Additionally, information letters were distributed to agencies who had expressed an interest in 
available treatment services. All referred respondents were then screened for eligibility based on 
inclusion and exclusion criteria using administrative data and informant interview. Once eligible 
participants were identified and consent obtained, they were asked to invite their preferred 
caregiver to attend the group with them. Subsequently, caregivers were either given or sent a 
letter of information and consent form for attendance. Written consent was confirmed at pre-
assessment; with consent for participant involvement including the use of a multi-modality 
approach of both written text and verbal discourse. 
 

Participants and caregivers were then de-identified and randomly assigned utilizing a 
relevant software (Randomizer.org; or “Research Randomizer”) with the researcher blind to 
group identities. Randomization occurred once a dozen participants were recruited and then 
again prior to the second group to accommodate rolling recruitment. Participants were initially 
allocated to either the treatment group or waitlist control group for one of the three sequential 
groups. All participants attended their assigned group except for one who requested an earlier 
group due to travel limitations and one replacement for the last group following client attrition.  
 
Measures 
 
Participation in the aDBT-ID trial was initiated by recruitment letters and by convenience 
sampling through partnering agencies. Referrals were initially screened for eligibility criteria e.g. 
level of ID and ASD, and availability of both client and caregiver for the trial and time 
commitment required for group randomization and attendance. Upon referral and consent by 
both client and caregiver, an interview was conducted by a research assistant (independent from 
the research team and blind to the group allocation) who confirmed eligibility and obtained 
written consent. The interview was completed prior to randomization to one of the three groups, 
and one month prior to group commencement. The interview included a demo-graphic 
questionnaire which included information on age, gender, locality, living arrangements, affiliated 
agency, caregiver role and experience, diagnoses, medications, and existing clinical services and 
supports.  
 
After the questionnaire, a two part assessment involving an interview and psychometric 
measures was conducted. The interview conducted with clients to identify insight into their own 
emotional and behavioural difficulties, and their motivation to gain coping skills with these 
difficulties. Caregivers were also interviewed about their perspectives of the client’s overall 
profile and need for treatment. The second part included a battery of both psychometric and 
observational measures to gather baseline measures of client emotional regulation, anger control 
and psychopathology. Standardized measures included the Difficulties in Emotional Regulation 
Scale (Gratz & Roemner, 2004), Novaco Anger Scale: Provocation Inventory (Novaco, 2003), 
and Reiss Scale of Dual Diagnosis (Reiss, 1990), respectively. The caregiver interview aimed to 
identify what they perceived the presenting problems to be, the effect of the issue(s), how they 
addressed the issue with the participant, and coping strategies currently utilized. The matched 
caregiver pre-assessment measures included the Emotion Regulation Checklist (Cicchetti & 
Shields, 1997; adapted with written permission by Cicchetti, 2016), Novaco Anger Scale: 
Provocation Inventory (Novaco, 2003) and Reiss Scale of Dual Diagnosis (Reiss, 1990). 
Measures were completed in relation to caregiver perspectives of clients’ profiles of emotional 
regulation, anger control and mental health difficulties. The psychometric measures noted above 
all have robust validity indices as noted in their respective manuals.  
 

Following group treatment, interviews and post assessments were conducted by 
independent research assistants, with both participants and caregivers, within approximately four 
weeks of group completion. In addition to re-administered assessments to measure potential 
change, the post-interview included an update and feedback questionnaire that focused on their 
qualitative experiences participating in the group, what they learned, whether they believed the 
skills presented would benefit their daily lives, coping strategies that they were currently 
utilizing, and feedback regarding suggested changes to the group. They were also asked about 
any significant changes in their circumstances since their group attendance (e.g. residential 
moves, hospitalizations, or legal charges) to illustrate possible contributory attrition factors if 
applicable. Also administered was an adapted multiple choice questionnaire, the Global 
Impression of Change: aDBT-ID. The measure was adapted from the Patients Global Impression 
of Change Scale (Hurst & Bolten, 2004) and then reviewed with the research team for face 
validity. The questionnaire identified the initial presenting problems and then measured both 
client and caregiver perspectives of overall change following the group, and for each respective 
module; with five responses ranging from no change to significant change. Accordingly, the 
interviews with the caregivers matched the clients’ post assessment with the psychometric 
measures, feedback interview and GIC questionnaire. 
 
Statistical Analysis 
 
Outcomes for the group were evaluated using both quantitative and qualitative measures in order 
to identify any group treatment changes; but also to assess the experiences by both clients and 
caregivers in the treatment process and their views on participation in community-based 
research. Given the small sample group and attempts at research rigour, quantitative measures 
were analysed utilizing an ‘intent to treat’ paradigm such that all participants who started the 
group were included in analysis. Using a mixed method ANOVA within SPSS v24, group 
differences, within and between, were assessed using non-parametric analysis due to group 
composition i.e. Wilcoxon signed-rank and Man-Whitney U tests, respectively. 
Qualitative measures were evaluated using thematic analysis (Braun & Clarke, 2006) for both 
client and caregiver interviews to identify and illustrate thematic patterns through an iterative 
process of data immersion, category generation and theme identification followed by inter-rater 
verification.   
Post-assessment data was unable to be obtained for one participant and one caregiver, and as 
such both qualitative and quantitate components were conducted with a sample size of N=18.