Acceptance and commitment therapy for insomnia: an updated meta-analysis of randomized controlled trials

To evaluate the effects of acceptance and commitment therapy (ACT) for insomnia compared with waitlist/standard control conditions and cognitive behavioral therapy for insomnia (CBT-I).

A systematic review and meta-analysis of randomized controlled trials was conducted. We searched on PubMed, Embase, and the Cochrane Library for studies comparing ACT or ACT-based interventions with non-ACT conditions in patients with insomnia. Continuous outcomes were pooled using a restricted maximum likelihood random-effects model on R.

ACT showed moderate-to-large improvement in insomnia symptom severity compared with waitlist/standard controls (SMD - 0.67, 95% CI - 1.08 to - 0.25). We observed no significant difference in insomnia severity between ACT and CBT-I at posttreatment (SMD 0.21, 95% CI - 0.02 to 0.43) or at 6-month follow-up (SMD 0.14, 95% CI - 0.15 to 0.42). CBT-I showed significant improvement in remission (ISI < 8 at posttreatment) compared to ACT at posttreatment (RR 0.81; 95% CI 0.67 to 0.98), but not at follow-up (RR 0.78; 95% CI 0.47 to 1.29). Treatment response rates (> 7-point ISI reduction) did also not differ significantly. Compared with waitlist/standard control, ACT produced a small-to-moderate reduction in depression (SMD - 0.34, 95% CI - 0.57 to - 0.12) and anxiety symptoms (SMD - 0.42, 95% CI - 0.67 to - 0.17).

ACT can be an efficacious treatment for insomnia with particularly strong outcomes for its psychological symptoms. Nevertheless, CBT-I remains the gold standard due to its more extensive and consistent evidence base.