Psychiatry · Medical Literature
Acceptance and commitment therapy for insomnia: an updated meta-analysis of randomized controlled trials.
Abstract
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 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.
Clinical relevance
In adults with insomnia, how effective is acceptance and commitment therapy (ACT) compared with (1) waitlist or standard control conditions and (2) cognitive behavioral therapy for insomnia (CBT-I) on insomnia symptom severity, remission, and treatment response? __SNAPSHOT__ {"studyDesign":"Systematic review and meta-analysis of randomized controlled trials; restricted maximum likelihood random-effects model","setting":"International; databases searched: PubMed, Embase, and Cochrane Library; individual trial settings not reported in abstract","sampleSize":"Not reported in abstract (number of included RCTs and total participants not specified in the provided text)","population":"Adults with insomnia (primary or comorbid); specific inclusion/exclusion criteria beyond insomnia diagnosis not reported in abstract","intervention":"Acceptance and commitment therapy (ACT) or ACT-based interventions for insomnia","comparator":"Two comparators: (1) waitlist or standard control conditions; (2) cognitive behavioral therapy for insomnia (CBT-I)","primaryOutcome":"Insomnia symptom severity (continuous, pooled as standardized mean difference [SMD]); secondary outcomes include remission (ISI 7 points)","followUp":"Post-treatment and 6-month follow-up reported; earlier or longer follow-up timepoints not specified in abstract","fundingSource":"Not reported"}
Key findings
Versus waitlist/standard control: ACT produced a moderate-to-large improvement in insomnia symptom severity (SMD −0.67, 95% CI −1.08 to −0.25), a statistically significant and directionally meaningful effect. Versus CBT-I at post-treatment: no statistically significant difference in insomnia severity was observed (SMD 0.21, 95% CI −0.02 to 0.43; p not reported); the upper confidence limit approaching 0.43 suggests a clinically plausible, if modest, advantage for CBT-I that cannot be excluded. At 6-month follow-up versus CBT-I: similarly no significant difference in insomnia severity (SMD 0.14, 95% CI −0.15 to 0.42). Remission (ISI 7 points): results were reported in the abstract but the sentence was truncated; specific effect sizes, confidence intervals, and p-values for this outcome are not available from the provided text. Adverse events: not reported in the provided abstract.
Practice implications
This meta-analysis establishes that ACT produces clinically meaningful reductions in insomnia severity compared with no active treatment, supporting its utility as an active behavioral intervention. However, at post-treatment, CBT-I achieves significantly higher rates of ISI remission (ISI 7-point reduction) was truncated; this outcome cannot be interpreted.,Pooling 'ACT or ACT-based interventions' may introduce substantial clinical heterogeneity: session number, format (individual vs. group vs. digital), therapist training, and ACT component emphasis likely varied across included trials.,Similarly, CBT-I protocols across trials likely varied in content (sleep restriction, stimulus control, sleep hygiene, cognitive restructuring) and intensity, potentially diluting or inflating the comparison.,Remission threshold of ISI < 8 is a surrogate/patient-reported endpoint; polysomnographic or actigraphic sleep outcomes were not mentioned in the abstract.,The 6-month follow-up remission analysis (RR 0.78, 95% CI 0.47–1.29) has a very wide confidence interval, indicating low precision and inadequate power to detect or exclude a clinically meaningful difference.,Funding source not reported; potential for publication bias or sponsor influence cannot be assessed.,Generalizability is uncertain: comorbid insomnia subgroups, older adults, adolescents, and populations with limited access to in-person therapy may not be adequately represented.,The direction of the continuous severity SMD for the ACT vs. CBT-I comparison (SMD 0.21 favoring CBT-I) did not cross zero but the confidence interval included zero, underscoring borderline statistical uncertainty.,Statistical significance and clinical importance are not synonymous; a difference in SMD of 0.21 on the ISI may not translate to a meaningful patient-level difference in daily functioning or quality of life. __BOTTOM_LINE_CATEGORY__ potentially_practice_informing __BOTTOM_LINE__ ACT produces moderate-to-large improvements in insomnia severity versus no treatment, confirming its efficacy as an active intervention. At post-treatment, CBT-I achieves higher remission rates (ISI < 8) than ACT, but this advantage appears to narrow by 6-month follow-up and is not reflected in continuous severity measures at either timepoint. ACT warrants consideration as an alternative for patients who decline or cannot access standard CBT-I, but CBT-I remains the better-supported first-line psychological treatment until full-text data, heterogeneity analyses, and GRADE certainty ratings are available for comprehensive evaluation.