0372 Digital Cognitive Behavioral Therapy for Insomnia Reduces Incident Depression at One-year Follow-up

Insomnia is a modifiable risk for depression, and a growing body of evidence indicates that targeted insomnia treatment also alleviates concurrent depression. However, few studies have examined if insomnia treatment may be effective in preventing incident depression. This is particularly relevant given the advent of internet delivered insomnia interventions, which has significant scalability given its cost-effectiveness and easy accessibility. As such, this study examined the efficacy of digital cognitive behavioral therapy (dCBT-I) in preventing incident depression. Other functional outcomes were also examined as secondary measures. 658 individuals with insomnia (DSM-5 diagnostic criteria) were randomized into two conditions: dCBT-I (N=358), or an online sleep education control (N=300). Participants were assessed at three time-points: pre-treatment, post-treatment, and one-year follow-up. Incidence of depression at each time point was operationalized as a score greater than 10 on the Quick Inventory of Depressive Symptomatology (QIDS). Assessments of functional outcomes included cognitive and affective functioning, work productivity, and social functioning. Among those who did not report significant depression at baseline (N=339), incident depression at post-treatment was lower in the dCBT-I condition (6.5%) than the sleep education condition (11.0%), though this difference was not statistically significant. However, incident depression at one-year follow-up was over four times lower in the dCBT-I condition (5.1%) compared to the sleep education condition (22.0%), χ2(1)=8.7, p=.003. Examination of other functional outcomes also showed greater improvements in the dCBT-I condition relative to the control group. Findings from this study provide evidence for the potential for dCBT-I to prevent incident depression in those with insomnia. Support for this study was provided from the Robert Wood Johnson Foundation, and from the National Institute of Mental Health R56MH115150 awarded to Dr. Christopher Drake.