Assessing the Impact of Digital Cognitive Behavioural Therapy for Insomnia on Depression Symptoms and Processes in Young Adults.

Digital Cognitive Behavioural Therapy for Insomnia (Digital CBTI). Rationale: Digital CBTI (i.e., CBTI delivered in a digital format) is a well validated treatment for Insomnia. CBTI programs are known to effectively reduce symptoms of depression without directly targeting non-sleep symptoms. However, the mechanisms which underlie the association between improvement in insomnia and improvements in depression are not well understood. Many candidate mechanisms have been proposed (e.g., cognitive biases), yet, there is a lack of research which investigates these possible mechanisms, and data from treatment studies is greatly needed to investigate the causal role of these mechanisms in the association between insomnia and depression. Type: Non-drug, online, interactive Setting/location: Online, any location in Australia Duration: 5 x 20 minute online sessions, delivered over 5 consecutive weeks Protocol: This program is based on CBTI, the recommended treatment for insomnia (e.g. Qaseem et al., 2016, Ann Intern Med, DOI: 10.7326/M15-2175). It is based on a digitised version of a brief CBTI protocol described in a scientific article in the Australian Journal of General Practice (Sweetman et al., 2021, AJGP, doi: 10.31128/AJGP-04-20-5391). Content: Each session will be administered online (computer or mobile phone). Each session will contain videos, text, and images. Participants will be asked to enter text-based, numerical (e.g. minutes of sleep duration) and multiple-choice data throughout the program. Participants will receive tailored therapy recommendations (e.g., prescribed time in bed) during each weekly session, determined by an in-built algorithm and participants' entered data (see Sweetman et al., 2021, Aus J General Practice for tailored therapy recommendations). Immediately after each session is completed, participants will receive an automated follow-up email with session-specific 'follow-up' information and tailored therapy recommendations including recommended bedtime window (approximate reading time: 15 minutes). Participants will receive another automated email one week later with a link to start each subsequent session. Videos are presented by researchers, psychologists, and sleep technicians, each with extensive experience (>8 years) in the management of insomnia. Tailoring / personalisation: Therapy recommendations will be tailored to participant's insomnia symptoms at baseline and weekly changes in symptoms throughout the program. Bedtime Restriction Therapy (initial restriction of time in bed to consolidate sleep, and subsequent gradual extension of time in bed) is a core component of CBTI. Bedtime restriction recommendations will be tailored to the specific sleep/wake information that participants provide. Primary therapeutic components: Psychoeducation about sleep, Bedtime restriction therapy, Stimulus Control Therapy, Relaxation Therapy, Cognitive Refocusing, Relapse Prevention. Adherence assessment: Adherence will be defined as the number of participants commencing each of the 5 online sessions. This information is automatically collected through the online system.