Investigating the Feasibility, Acceptability, and Preliminary Effectiveness of a Sleep Intervention for Adolescents With Co-morbid Insomnia and Mental Health Difficulties
Phase: NA
Conditions: Insomnia, Mental Health Issue
Sponsor: Stephanie McCrory

Study Title: Investigating the feasibility, acceptability, and preliminary effectiveness of 
a sleep intervention                       for adolescents with comorbid insomnia and mental 
health difficulties. 
 
 
Chief Investigator: 
Stephanie McCrory 
PhD Student  
University of Strathclyde 
 
 
Supervised by: 
Dr Leanne Fleming, PhD 
Reader  
University of Strathclyde 
 
Dr Megan Crawford, PhD 
Senior Lecturer  
University of Strathclyde 
 
Dr Kenneth MacMahon, PhD 
Clinical Psychologist 
NHS CAMHS 
 
 
 
 
Protocol Version: 
Protocol Version 8 
10/04/25 
 
 

Study objectives: 
1. To assess the feasibility of delivering the Strathclyde Sleep Intervention to 
adolescents with co-morbid insomnia and mental health attending a mental health 
services. The following feasibility benchmarks will be assessed: recruitment and 
retention, participant attendance, staff training, intervention fidelity and participant 
adherence. 
2. To examine participant acceptability. The researchers will conduct qualitative 
interviews with the participants and delivery staff to examine the acceptability of the 
programme. 
3. To investigate the preliminary effectiveness by assessing the following: sleep 
parameters, insomnia symptoms, Circadian phase preference (baseline only) and 
mental health symptoms. Data will be collected at baseline, post-intervention and 3-
month follow-up. 
 
Methods:  
Design – The study will assess the feasibility, acceptability, and preliminary effectiveness of 
the intervention using a single-arm repeated measures design. Data to assess the feasibility 
objectives and benchmarks will be collected throughout. Acceptability will be explored via 
qualitative interviews following the delivery of the intervention. Outcomes will be measured 
at baseline, immediately post-treatment and at 3-month follow-up.  
 
Participants - We intend to assess the feasibility of recruitment of adolescents from mental 
health services, therefore no formal power calculation has been conducted for this study. We 
aim to recruit up to 40 adolescents and up to 10 members of staff. This estimate was based on 
previous research conducted within adolescents in mental health services (Åslund et al., 
2020; Bradley et al., 2018; Clarke et al., 2015; Palermo et al., 2017; Rollinson et al., 2021). 
The results of this study will inform sample size calculations for future RCT of the 
Strathclyde Sleep Intervention.  
 
Eligibility criteria –  
Inclusion criteria:  
1. Adolescents aged 12-18 years 

2. Meeting thresholds for insomnia disorder (determined by cut-off scores on 
the Sleep Condition Indicator (2) - <2 indicates probable insomnia, Luik et 
al., 2019)     
3. Receiving support for mental health  
4. Able to engage with intervention protocol  
 
Exclusion criteria:  
1. Active suicide ideation and/or recent suicidal attempts 
2. Contraindicators for components of CBT-I (sleep restriction therapy) 
including seizure disorders/conditions including epilepsy, bipolar disorder, 
symptoms of psychosis, obstructive sleep apnea and parasomnias. 
3. Diagnosis of Autism Spectrum Disorder, Attention Deficit Hyperactivity 
Disorder, Foetal Alcohol Spectrum Disorder (Neurodiversity) 
4. Those who are currently completing, or have recently completed (in the 
past 6 months), CBT-I for insomnia elsewhere (or components of CBT-I 
including e.g. sleep restriction therapy, stimulus control, cognitive 
techniques). This will only include in-person, one-to-one methods of 
delivery. 
 
Procedure - Staff will be identified by the service management and volunteer to receive 
training. We intend to train up to 10 members of staff to deliver the intervention. Staff will 
receive training, will be offered ongoing supervision (provided by the research team), and 
will utilize the intervention delivery manual to deliver the intervention. A list of common 
FAQs will also be provided to support the delivery. Staff within the service will use a referral 
form (accessible via Qualtrics) to assess eligibility and refer potential participants, they will 
also be responsible for sharing the participant information sheet and video link. Adolescents 
and caregivers will be advised that the researcher will be in contact with them in 2-3 working 
days to arrange a time to meet on Zoom. During the meeting, the researcher will re-check 
eligibility to ensure nothing has changed since the referral form was completed, to answer 
any questions and to obtain verbal consent. The adolescents and caregivers will also be sent a 
URL link to the written consent form (accessed online via Qualtrics). Written consent will be 
obtained from adolescents and parents/caregivers. Forms will inform participants about their 
right to withdraw from the intervention and/or data collection/analysis at any time, until the 
end of the follow-up assessment.  

After receiving a signed consent form, participants will be sent an email with a link to 
complete a baseline assessment questionnaire. The participants will also be asked to complete 
a sleep diary for up to 2-weeks before the delivery of the Strathclyde Sleep Intervention. 
Participants will be invited to attend 4 weekly sessions for the delivery of the intervention. 
Trained staff will deliver the intervention to small groups of adolescents (up to 6). All 
sessions will be audio recorded. The participants will be asked to complete a sleep diary for 
the duration of the intervention. This will take approximately 2-3 minutes to complete and is 
necessary to ensure the sleep window can be appropriately titrated during sleep restriction 
therapy. Following the delivery of the intervention, all participants will be asked to complete 
the post-intervention assessment (questionnaire, 2-week sleep diary), and will be invited to 
attend semi-structured interviews with a member of the research team to explore the 
acceptability of the intervention. The staff will also be invited to attend semi-structured 
interviews to explore the acceptability of training, delivery, and future implementation. Staff 
will be asked to read an information sheet and provide informed consent prior to the 
interview. Interviews will be conducted following the completion of post-intervention 
assessments and will be audio-recorded. Three months following completion of the post-
intervention assessment, the participants will be asked to complete the follow-up assessment 
(questionnaire, 2-week sleep diary). This will be the end of their participation in the study.   
 
Data analysis plan - To examine the feasibility of delivering the intervention to adolescents 
attending mental health services, we will examine recruitment and retention rates, attendance 
logs and adherence to intervention components using frequencies and descriptive statistics. 
An intervention fidelity checklist will also be created, and the researchers will score the 
delivery of the intervention against the checklist. Qualitative data will be transcribed 
verbatim and analysed using Braun and Clarke’s (2006) method of thematic analysis to 
examine acceptability. To examine preliminary effectiveness, we will compare changes in 
sleep parameters, insomnia and mental health symptoms from baseline, post-intervention and 
follow-up using mixed modelling analysis.