Cognitive behavioral therapy for insomnia in people with schizophrenia: a systematic review and meta-analysis

Cognitive behavioral therapy for insomnia (CBT-I) is the first-line treatment for insomnia in general population, but only recently has it begun to be examined among people with schizophrenia. We aimed to summarize the currently available evidence by the systematic review and meta-analysis.

Multiple databases, including PubMed, Cochrane Central Register of Controlled Trials and PsycINFO were searched up to 1st October 2024 to include all randomized controlled trials examining CBT-I among adults with insomnia and schizophrenia. We evaluated the certainty of evidence using GRADE. The co-primary outcomes were insomnia severity and overall schizophrenia symptoms at post-treatment. Secondary outcomes included all-cause dropouts, adverse events, other psychotic symptoms and self-reported sleep continuity measures. We conducted frequentist random-effects pairwise meta-analyses. This study was prospectively registered (https://osf.io/ja3cg/).

Three trials with 137 randomized participants were identified (mean age, 42.0 [standard deviation, 12.9]; 39.4 % women; mean baseline Positive and Negative Syndrome Scale, 70.7 [16.8]; mean baseline Insomnia Severity Index, 18.9 [4.5]). CBT-I was more beneficial than treatment as usual for insomnia severity (SMD -1.53 [95 % Confidence Interval (CI), -2.04 to -1.02; GRADE certainty of evidence: low), but the effect on overall schizophrenia symptoms remained unclear (SMD -0.29 [95 %CI, -0.70 to 0.12]: low). Most of the secondary outcomes were examined in only a single trial at most, and confidence intervals were very wide.

This meta-analysis found that CBT-I may improve insomnia symptoms among people with schizophrenia but its effect on other schizophrenia-related symptoms remained unclear. Further larger trials are needed.