Effekten av intraindividuell variasjon av søvn ved internettbasert kognitiv atferdsterapi for insomni

Forskere fra NTNU, St. Olavs Hospital, Folkehelseinstituttet, University of Virginia og University of Newcastle har i denne studien undersøkt om individuelle variasjoner av søvn ble endret med internettbasert kognitiv atferdsterapi for insomni (dCBT-I), og om endringen var en mediator av dCBT-I på alvorlighetsgrad av insomni og psykiske plager. Funnene viste at reduksjon i individuelle variasjoner av søvn medierte betydelige endringer i alvorlighetsgrad av insomni og psykiske plager ved bruk av dCBT-I. Disse funnene gir viktige bevis om den terapeutiske effekten av dCBT-I og kan påvirke utviklingen av denne behandlingsformen.

Publisert 04.11.2021

The effect of sleep-wake intraindividual variability in digital cognitive behavioral therapy for insomnia: a mediation analysis of a large-scale RCT

Cecilie L Vestergaard, Øystein Vedaa, Melanie R Simpson, Patrick Faaland, Daniel Vethe, Kaia Kjørstad, Knut Langsrud, Lee M Ritterband, Børge Sivertsen, Tore C Stiles, Jan Scott, Håvard Kallestad

Studien er publisert i Sleep

Study objectives: Digital cognitive behavioral therapy for insomnia (dCBT-I) is an effective treatment for insomnia. However, less is known about mediators of its benefits. The aim of the present study was to test if intraindividual variability in sleep (IIV) was reduced with dCBT-I, and whether any identified reduction was a mediator of dCBT-I on insomnia severity and psychological distress.

Methods: In a two-arm randomized controlled trial (RCT), 1720 adults with insomnia (dCBT-I = 867; patient education about sleep = 853) completed the Insomnia Severity Index (ISI), the Hospital Anxiety and Depression Scale (HADS) and sleep diaries, at baseline and 9-week follow-up. Changes in IIV were analyzed using linear mixed modeling followed by mediation analyses of ISI, HADS, and IIV in singular sleep metrics and composite measures (behavioral indices (BI-Z) and sleep disturbance indices (SI-Z)).

Results: dCBT-I was associated with reduced IIV across all singular sleep metrics, with the largest between-group effect sizes observed for sleep onset latency (SOL). Reduced IIV for SOL and wake after sleep onset had the overall greatest singular mediating effect. For composite measures, SI-Z mediated change in ISI (b = -0.74; 95% confidence interval (CI) -1.04 to -0.52; 13.3%) and HADS (b = -0.40; 95% CI -0.73 to -0.18; 29.2%), while BI-Z mediated minor changes.

Conclusion: Reductions in IIV in key sleep metrics mediate significant changes in insomnia severity and especially psychological distress when using dCBT-I. These findings offer important evidence regarding the therapeutic action of dCBT-I and may guide the future development of this intervention.