Depression prevention via digital cognitive behavioral therapy for insomnia: a randomized controlled trial

Abstract

Study objectives: Insomnia is a common precursor to depression; yet, the potential for insomnia treatment to prevent depression has not been demonstrated. Cognitive behavioral therapy for insomnia (CBT-I) effectively reduces concurrent symptoms of insomnia and depression and can be delivered digitally (dCBT-I); however, it remains unclear whether treating insomnia leads to sustained reduction and prevention of depression. This randomized controlled trial examined the efficacy of dCBT-I in reducing and preventing depression over a 1-year follow-up period.

Methods: Patients with Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) insomnia disorder were randomly assigned to receive dCBT-I or an attentional control. The follow-up sample included 358 patients in the dCBT-I condition and 300 patients in the online sleep education condition. The primary outcome measure was relative rate ratios for depression at 1-year follow-up. Insomnia responses to treatment were also tested as predictors of incident depression at the 1-year follow-up.

Results: At 1-year follow-up, depression severity continued to be significantly lower in the dCBT-I condition relative to control. In addition, the number of individuals who reported no depression at 1-year follow-up was 51% higher in the dCBT-I condition relative to control. In those with minimal to no depression at baseline, the incident rate of moderate-to-severe depression at 1-year follow-up was reduced by half in the dCBT-I condition relative to the control condition.

Conclusion: dCBT-I showed robust effects as an intervention that prevents depression. Future research should examine dose-response requirements and further characterize mechanisms of action of dCBT-I for depression prevention.

Clinical trial: Sleep to Prevent Evolving Affective Disorders; NCT02988375.

Keywords: depression; insomnia; intervention; mobile health; prevention.

© Sleep Research Society 2019. Published by Oxford University Press [on behalf of the Sleep Research Society]. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Figures

Figure 1.

Flow chart of enrollment. Non-engagement in the intervention (i.e. no-show) was defined as those who did not complete the first session of dCBT-I.

Figure 2.

Change in depression severity from pretreatment to 1-year follow-up. Error bars represent 95% confidence intervals. QIDS-SR16 = 16 item self-report Quick Inventory of Depressive Symptomatology.

Figure 3.

One-year incidence of moderate-to-severe depression is lower in the dCBT-I compared to the control condition. Error bars represent 95% confidence intervals.