Circadian rhythm and aggressive behavior in community-dwelling schizophrenia patients testing a moderated mediation model

Background: Aggressive behavior in patients with schizophrenia poses significant challenges to community management. Although disruption of circadian rhythm is a recognized risk factor, the underlying mechanisms related to sleep disorders and social support remain unclear. Objective: This study conducted a cross-sectional survey to investigate the impact of circadian rhythm on aggressive behavior in community-dwelling schizophrenia patients, and tested a moderate mediation model focusing on sleep disorders and perceived social support. Method: A total of 818 patients with schizophrenia were recruited from 28 communities in China. After data quality checks, 785 participants (effective response rate: 95.97%) were included in the final analysis. Participants completed self-report measures assessing chronotype (Morningness-Eveningness Questionnaire-5, MEQ-5), sleep quality (Pittsburgh Sleep Quality Index, PSQI), perceived social support (Perceived Social Support Scale, PSSS), and aggressive behavior over the past month (Modified Overt Aggression Scale, MOAS). A moderated mediation model was tested using the PROCESS macro. Results: The results demonstrated that circadian rhythm(as assessed by chronotype preference) are associated with aggressive behavior both directly and indirectly through sleep disorders. Furthermore, perceived social support moderated the relationships among circadian rhythm, sleep disorders, and aggressive behavior by providing a tripartite protective function. Conclusion: In this clinically stable community sample, eveningness preference and sleep disturbance were associated with higher levels of self-reported aggression, while perceived social support appeared to buffer these relationships. These cross-sectional findings suggest potential targets for psychosocial intervention but require longitudinal confirmation.