An online behavioural self-help intervention rapidly improves acute insomnia severity and subjective mood during the COVID-19 pandemic: a stratified randomised controlled trial.

STUDY OBJECTIVES: Stressful life events, such as the COVID-19 pandemic, can cause acute insomnia. Cognitive behavioural therapy for acute insomnia is effective but is both time and resource-intensive. This study investigated if an online behavioural self-help intervention, which has been successfully used alongside sleep restriction for acute insomnia, reduced insomnia severity and improved mood in acute insomnia. This study also assessed good sleepers to explore if a "sleep vaccination" approach was feasible.

METHODS: In this online stratified randomised controlled trial, 344 participants (103 good sleepers and 241 participants with DSM-5 acute insomnia) were randomised to receive the intervention/no intervention (good sleepers) or intervention/intervention after 28 days (poor sleepers). Insomnia severity was assessed using the ISI (primary outcome), and anxiety and depression using the GAD-7/PHQ-9 (secondary outcomes) at baseline, one week, one month and three-month follow-up.

RESULTS: In people with acute insomnia, relative to baseline, there were significant reductions in ISI (dz = 1.17), GAD-7 (dz = .70) and PHQ-9 (dz = .60) scores at one week follow-up. ISI, GAD-7 and PHQ-9 scores were significantly lower at all follow-up time points, relative to baseline. Subjective diary-derived sleep continuity was unaffected. No beneficial effects upon sleep or mood were observed in good sleepers.

CONCLUSIONS: An online behavioural self-help intervention rapidly reduces acute insomnia severity (within one week), and benefits mood in people with acute insomnia. These beneficial effects are maintained up to three months later. Although the use of the intervention is feasible in good sleepers, their subjective sleep was unaffected.