Digital cognitive behaviour therapy for insomnia (dCBT-I): Chronotype moderation on intervention outcomes.

Using data from 1721 participants in a community-based randomized control trial of digital cognitive behavioural therapy for insomnia compared with patient education, we employed linear mixed modelling analyses to examine whether chronotype moderated the benefits of digital cognitive behavioural therapy for insomnia on self-reported levels of insomnia severity, fatigue and psychological distress. Baseline self-ratings on the reduced version of the Horne-Östberg Morningness-Eveningness Questionnaire were used to categorize the sample into three chronotypes: morning type (n = 345; 20%); intermediate type (n = 843; 49%); and evening type (n = 524; 30%). Insomnia Severity Index, Chalder Fatigue Questionnaire, and Hospital Anxiety and Depression Scale were assessed pre- and post-intervention (9 weeks). For individuals with self-reported morning or intermediate chronotypes, digital cognitive behavioural therapy for insomnia was superior to patient education on all ratings (Insomnia Severity Index, Chalder Fatigue Questionnaire, and Hospital Anxiety and Depression Scale) at follow-up (p-values ≤ 0.05). For individuals with self-reported evening chronotype, digital cognitive behavioural therapy for insomnia was superior to patient education for Insomnia Severity Index and Chalder Fatigue Questionnaire, but not on the Hospital Anxiety and Depression Scale (p = 0.139). There were significant differences in the treatment effects between the three chronotypes on the Insomnia Severity Index (p = 0.023) estimated difference between evening and morning type of -1.70, 95% confidence interval: -2.96 to -0.45, p = 0.008, and estimated difference between evening and intermediate type -1.53, 95% confidence interval: -3.04 to -0.03, p = 0.046. There were no significant differences in the treatment effects between the three chronotypes on the Chalder Fatigue Questionnaire (p = 0.488) or the Hospital Anxiety and Depression Scale (p = 0.536). We conclude that self-reported chronotype moderates the effects of digital cognitive behavioural therapy for insomnia on insomnia severity, but not on psychological distress or fatigue.

Faaland P ，Vedaa Ø ，Langsrud K ，Sivertsen B ，Lydersen S ，Vestergaard CL ，Kjørstad K ，Vethe D ，Ritterband LM ，Harvey AG ，Stiles TC ，Scott J ，Kallestad H ... -  《-》

Short and long-term effects of unguided internet-based cognitive behavioral therapy for chronic insomnia in morning and evening persons: a post-hoc analysis.

Lien M ，Bredeli E ，Sivertsen B ，Kallestad H ，Pallesen S ，Smith ORF ，Faaland P ，Ritterband LM ，Thorndike FP ，Vedaa Ø ... -  《-》

Digital cognitive behaviour therapy for insomnia in individuals with self-reported insomnia and chronic fatigue: A secondary analysis of a large scale randomized controlled trial.

Insomnia is associated with fatigue, but it is unclear whether response to cognitive behaviour therapy for insomnia is altered in individuals with co-occurring symptoms of insomnia and chronic fatigue. This is a secondary analysis using data from 1717 participants with self-reported insomnia in a community-based randomized controlled trial of digital cognitive behaviour therapy for insomnia compared with patient education. We employed baseline ratings of the Chalder Fatigue Questionnaire to identify participants with more or fewer symptoms of self-reported chronic fatigue (chronic fatigue, n = 592; no chronic fatigue, n = 1125). We used linear mixed models with Insomnia Severity Index, Short Form-12 mental health, Short Form-12 physical health, and the Hospital Anxiety and Depression Scale separately as outcome variables. The main covariates were main effects and interactions for time (baseline versus 9-week follow-up), intervention, and chronic fatigue. Participants with chronic fatigue reported significantly greater improvements following digital cognitive behaviour therapy for insomnia compared with patient education on the Insomnia Severity Index (Cohen's d = 1.36, p < 0.001), Short Form-12 mental health (Cohen's d = 0.19, p = 0.029), and Hospital Anxiety and Depression Scale (Cohen's d = 0.18, p = 0.010). There were no significant differences in the effectiveness of digital cognitive behaviour therapy for insomnia between chronic fatigue and no chronic fatigue participants on any outcome. We conclude that in a large community-based sample of adults with insomnia, co-occurring chronic fatigue did not moderate the effectiveness of digital cognitive behaviour therapy for insomnia on any of the tested outcomes. This may further establish digital cognitive behaviour therapy for insomnia as an adjunctive intervention in individuals with physical and mental disorders.

Ramfjord LS ，Faaland P ，Scott J ，Saksvik SB ，Lydersen S ，Vedaa Ø ，Kahn N ，Langsrud K ，Stiles TC ，Ritterband LM ，Harvey AG ，Sivertsen B ，Kallestad H ... -  《-》

Dysfunctional beliefs and attitudes about sleep (DBAS) mediate outcomes in dCBT-I on psychological distress, fatigue, and insomnia severity.

Digital cognitive behavioral therapy for insomnia (dCBT-I) improves several sleep and health outcomes in individuals with insomnia. This study investigates whether changes in Dysfunctional Beliefs and Attitudes about Sleep (DBAS) during dCBT-I mediate changes in psychological distress, fatigue, and insomnia severity. The study presents a secondary planned analysis of data from 1073 participants in a randomized control trial (Total sample = 1721) of dCBT-I compared with patient education (PE). Self-ratings with the Dysfunctional Beliefs and Attitudes about Sleep (DBAS), the Hospital Anxiety Depression Scale (HADS), the Chalder Fatigue Scale (CFQ), and the Insomnia Severity Index (ISI) were obtained at baseline and 9-week follow-up. Hayes PROCESS mediation analyses were conducted to test for mediation. sDBAS scores were significantly reduced at 9-week follow-up for those randomized to dCBT-I (n = 566) compared with PE (n = 507). The estimated mean difference was -1.49 (95% CI -1.66 to -1.31, p < .001, Cohen's d. = 0.93). DBAS mediated all the effect of dCBT-I on the HADS and the CFQ, and 64% of the change on the ISI (Estimated indirect effect -3.14, 95% CI -3.60 to -2.68) at 9-week follow-up compared with PE. Changes in the DBAS fully mediated the effects of dCBT-I on psychological distress and fatigue, and the DBAS partially mediated the effects on insomnia severity. These findings may have implications for understanding how dCBT-I works and highlights the role of changing cognitions in dCBT-I.

Faaland P ，Vedaa Ø ，Langsrud K ，Sivertsen B ，Lydersen S ，Saksvik SB ，Vestergaard CL ，Kjørstad K ，Vethe D ，Ritterband LM ，Harvey AG ，Stiles TC ，Scott J ，Kallestad H ... -  《-》

Digital cognitive behavioral therapy for insomnia for people with comorbid psychological distress: A large scale randomized controlled trial.

To examine if comorbid anxiety and depression symptoms (psychological distress) moderate intervention effect in participants receiving digital Cognitive Behavioral Therapy for Insomnia (dCBT-I) in a large-scale randomized controlled trial (RCT), compared to a patient education (PE) control condition. Further, we investigate if dCBT-I reduced levels of psychological distress for those with insomnia and comorbid psychological distress. 1721 participants with insomnia completed online assessments of sleep, fatigue and psychological distress, at baseline and at nine-week follow-up. Primary outcome was Insomnia Severity Index (ISI), and secondary outcomes included self-reported sleep (diary), cognition, fatigue, and psychological distress. Participants with psychological distress (HADS>16) were separated from participants without psychological distress. Linear mixed models in SPSS were conducted to test the effects of the intervention. At nine-week follow-up we found no difference in effect of the intervention between those who had comorbid psychological distress vs. those without psychological distress in terms of insomnia severity (p = 0.552) and fatigue (p = 0.744). Both groups had large effect size improvements on insomnia severity (p < 0.001=), small to medium (Cohen d < 0.08) improvements on fatigue (p < 0.01=) and sleep efficiency (p < 0.001), and small improvement on other sleep diary measures, compared to their respective control group. The psychological distress group showed a small, but statistically significant decrease in psychological distress (d = 0.2, p < 0.05) with dCBT-I compared to PE. dCBT-I is a viable treatment for Insomnia also for those who have comorbid psychological distress.

Skoglund H ，Sivertsen B ，Kallestad H ，Vedaa Ø ... -  《-》