Sleep-specific outcomes attributable to digitally delivered cognitive behavioral therapy for insomnia in adults with insomnia and depressive symptoms

Objective Randomized controlled trials (RCTs) of digitally delivered Cognitive Behavioral Therapy for insomnia (CBT-I) have demonstrated reductions in insomnia severity, depression symptoms, anxiety symptoms, and suicidal ideation. The present study aimed to evaluate the effectiveness of self-guided, digital CBT-I to improve sleep-specific outcomes.Method An RCT of Australian adults with insomnia and depressive symptoms (N = 1149) compared SHUTi, a digital CBT-I intervention, with HealthWatch, an attention-matched control internet program, at baseline, posttest (9 weeks) and at 6-, 12-, and 18-month follow-ups. Online sleep diaries were used to derive measures of sleep-onset latency (SOL), wake after sleep onset (WASO), sleep efficiency (SE), number of awakenings, sleep quality, and total sleep time (TST).Results Participants in the SHUTi condition had greater improvements at posttest compared with control for: SOL, WASO, SE, number of awakenings, and sleep quality. These improvements were sustained at every follow-up (p < .02 for all outcomes except TST, in which statistically significant increases were observed only at 12- and 18-months).Conclusions Digitally delivered CBT-I produced lasting improvements in sleep outcomes among adults with insomnia and depressive symptoms. Findings provide further evidence of long-term improvements associated with a digital therapeutic for insomnia, compared to an attention-control condition.