iCBT intervention 'Space from Depression' with smartwatch as an additional means to self-report data on mood, sleep and physical activity in the 'Space from Depression' program (n=35).

iCBT intervention 'Space from Depression' (n=35).

This is a 7-module internet-based CBT program. The structure and content of the modules follow evidence-based CBT principles; they are structured to incorporate quizzes, videos, psychoeducational content and interactive tools, personalised homework suggestions and summaries. One of the interactive tools is the mood monitor, where users are encouraged to monitor their mood and reflect on several factors that might had influenced it. Clients are allocated to a psychological wellbeing practitioner (PWP). The PWP is responsible for monitoring and guiding the client's progress throughout the intervention. Over the course of the 8 week supported intervention period, on 6 separate occasions the PWP will review participants progress, leaving feedback for them and responding to the work they have completed. The basic share level allows PWP is to view users' goals for the week, key messages and progress points. Each PWP will provide post-session feedback of between 10 and 15 minutes per session.

All participants will be asked to fill in the Acceptability Questionnaire (AQ) upon consent, at 3 weeks, and at 8 weeks. These measurement points are aligned with Nadal et al. (2020) Technology Acceptance Lifecycle model. The questionnaire is based on the acceptance factors identified by Kim & Park (2012). The wording of the AQ is adapted to the technology in question (smartwatch vs mobile/desktop app). Participants will rate each statement on a 5-point Likert Scale. The 8-week AQ contains a series of open-ended questions for the smartwatch group to explore additional factors that might influence the watch app acceptance (privacy protection, resistance to change, etc.).

Participants in the smartwatch group who have indicated consent in taking part in the follow-up interview will be contacted after answering the final acceptance questionnaire.

The SAT (Richards et al, 2013) will be used to assess patient satisfaction with the intervention. This 5-item questionnaire has been used previously to evaluate different aspects of patient satisfaction and experience with the 'Space from Depression' intervention (Richards et al, 2013).

Score varies from 0 to 20; a higher score indicates a better outcome. The score is informed by 2 open-ended questions at the end of the questionnaire.

The PHQ-9 is a nine-item self-report measure of depression (Kroenke et al, 2001; Spitzer et al, 1999) that has been widely used in research and is employed as a clinical outcome measure in IAPT as part of its minimum dataset. The PHQ-9 items reflect the diagnostic criteria for depression outlined by the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (A.P. Association, 2013).

Score varies from 0 to 27; a higher score indicates a worse outcome.