Polysomnographic parameters in schizoaffective disorder: a systematic review and meta-analysis

A systematic review and meta-analysis of sleep studies in schizoaffective disorder were conducted using published articles researched in major databases within the period from inception to December 1, 2025. The sleep parameters: total sleep time, sleep efficiency, sleep latency, wakefulness, REM time and percentage, REM latency, REM density, stage 1, 2, 3 and 4 sleep time and percentage, delta sleep time and percentage, of drug-free schizoaffective patients were analyzed and, where available, compared with case-control data of healthy controls, depressed unipolar patients and schizophrenic patients. Forty studies were identified in the systematic review. Nine case-control studies with 67 schizoaffective patients, 88 schizophrenic patients, 79 healthy controls and 131 depressed patients were included in the meta-analyses. The primary outcome was the standard mean difference. Data were fitted with a random-effects model. Publication bias assessment was checked by Egger's Regression and funnel plot asymmetry. Patients with schizoaffective disorder showed reduced total sleep time, increased sleep latency and wakefulness, along with reduced REM time and shortened REM latency, reduced stage 4 sleep time and percentage compared to healthy controls. Patients with schizoaffective disorder differed from depressed patients only for increased sleep latency, while they did not show any difference compared to patients with schizophrenia. SZA showed a non-significant trend (p=0.08) towards increased REM density compared to SCZ, suggesting the need to better clarify the role of REM density in mood and psychotic disorders.