Digital Cognitive Behavioral Therapy Reduced Symptoms of Insomnia in Norwegian Adults

This study investigated the effect of a fully automated dCBT program on insomnia severity, sleep–wake patterns, sleep medication use, and daytime impairment.

Study data published in Lancet Digital Health support the efficacy of digital cognitive behavioral therapy (dCBT) for the treatment of insomnia in adults. Compared to receiving educational materials on sleep, patients who underwent dCBT experienced significantly greater reductions in insomnia symptoms over a period of 9 weeks.

This randomized controlled trial recruited adults with insomnia through a free-to-access website publicized in Norway. Individuals who had regular internet access and an Insomnia Severity Index (ISI) score of ≥12 were eligible for inclusion.

Participants were randomized 1:1 to receive 9 weeks of either dCBT for insomnia or online patient education on sleep.  The dCBT condition comprised 6 core interactive sessions which could be completed over the 9 weeks. The primary outcome was a change in ISI score from baseline to 9 weeks. Treatment response was characterized as an ISI score reduction of ≥8 points from baseline; an ISI score <8 constituted remission. Latent growth models were used to assess the effect of dCBT intervention on ISI score change. Effect sizes were estimated using Cohen’s d.  

Screening was conducted between February 26, 2016 and July 1, 2018. Overall, 1721 patients were enrolled: 868 received dCBT and 853 received online patient education. Mean age was 44.2 ± 13.9 years in the dCBT group and 44.8 ± 13.7 years in the education group. The majority (69%) of all participants were women. At the 9-week follow-up timepoint, 584 (67%) patients in the dCBT group and 534 (63%) in the education group completed the final ISI assessment. Over 9 weeks, mean ISI score decreased from 19.2 ± 3.9 to 10.4 ± 6.2 in the dCBT group and from 19.6 ± 4.0 to 15.2 ± 5.3 in the education group. The estimated mean difference in score change between groups was -4.7 (95% confidence interval [CI], -5.4 to -4.1; Cohen’s d, -1.21; P <.001). At 9 weeks, 58% of dCBT completers met criteria for treatment response, compared to 21% of completers in the education condition (P <.001). Additionally, 38% of participants in the CBT group achieved an ISI score indicating remission (ISI <8) at 9 weeks, compared to just 8% of the education group (P <.001).

To date, this study is one of the largest randomized controlled trials of digital CBT for insomnia. After 9 weeks, patients in the dCBT condition experienced significantly greater reductions in insomnia symptoms compared to patients in the control condition. As study limitations, investigators noted the low attrition rates (63-67%) and the use of self-report data rather than information from medical records. Further study is necessary to determine how best to disseminate dCBT for insomnia.

“Although a rapid implementation of new evidence-based innovations is important, it is also important to monitor the degree to which the efficacy shown in trials translates into clinical effectiveness, and to identify the optimal balance between therapist-delivered and self-guided interventions,” the investigators wrote.


Vedaa Ø, Kallestad H, Scott J, et al. Effects of digital cognitive behavioural therapy for insomnia on insomnia severity: a large-scale randomised controlled trial. Lancet Digital Health. 2020;2(8):E397-406.