Smartphone application‐delivered cognitive behavioural therapy for insomnia with telephone support for insomnia disorder compared to a waitlist control: a randomised clinical trial

Although there have been promising findings for smartphone application (app)-delivered cognitive behavioural therapy for insomnia (CBT-I), previous trials have not screened participants rigorously for insomnia disorder and used therapist support. Based on the above, we aimed to examine the effects of smartphone app-delivered CBT-I with telephone support against a waitlist (WL) in a sample with insomnia disorder. A total of 64 participants with insomnia disorder were randomised to smartphone app-delivered CBT-I (n = 32) or a WL (n = 32). Smartphone app-delivered CBT-I consisted of six weekly smartphone app modules with 15 min of telephone support per week. At pre- and post-treatment, and the 3-month follow-up, we assessed insomnia symptoms and associated correlates and consequences. At post-treatment, we also assessed measures related to adherence (therapist support, exercise/module completion), self-rated perception of treatment content, activity, and adverse events. CBT-I significantly outperformed the WL with large effects on the primary outcome (d = 2.26) and was significantly different on most of the secondary outcomes with medium to large effects. CBT-I also resulted in a significantly larger proportion of treatment remitters (CBT-I: 64.5-77.4%, WL: 6.5-6.9%) and responders (CBT-I: 77.4-90.3%, WL: 19.4-24.1%) at post-treatment and follow-up, compared to the WL. Treatment was associated with high satisfaction, high adherence, low attrition, and few treatment-impeding adverse events. Based on the medium to large effects of smartphone app-delivered CBT-I with telephone support, this trial highlights the potential of delivering CBT-I exclusively through an app with therapist telephone support for high efficacy, satisfaction, and adherence.