BACKGROUND: This study aimed to investigate the prevalence and predictors of suicidal ideation (SI) in patients with chronic schizophrenia, focusing on the mediating roles of depression, insomnia, and aggression.
METHODS: A cross-sectional study was conducted with 1271 patients diagnosed with chronic schizophrenia in China. Participants were assessed using the Beck Scale for Suicide Ideation (SSI), Hamilton Depression Rating Scale (HAMD), Insomnia Severity Index (ISI), Modified Overt Aggression Scale (MOAS), and Positive and Negative Syndrome Scale (PANSS). Mediation and serial mediation analyses were performed to examine the relationships among depression, insomnia, aggression, and SI.
RESULTS: The prevalence of SI was 16.44 %. Depression exhibited both direct and indirect effects on SI, mediated by insomnia (indirect effect = 0.255, 95 % CI [0.116, 0.426]) and aggression (indirect effect = 0.115, 95 % CI [0.014, 0.260]). Serial mediation analysis revealed a significant pathway: depression → insomnia → aggression → SI (β = 0.038, 95 % CI [0.003, 0.094]). Younger age, family history of mental illness, alcohol consumption, higher PANSS scores, and elevated HAMD and MOAS scores were significant predictors of SI.
CONCLUSION: The findings highlight the high prevalence of SI in chronic schizophrenia and underscore the complex interplay of depression, insomnia, and aggression in increasing suicide risk. Targeted interventions addressing these mediators, particularly insomnia and aggression, may mitigate SI in this population.
LIMITATIONS: The cross-sectional design precludes causal inferences. The sample was predominantly male and single, limiting generalizability. Self-reported measures may introduce bias, and medication effects were not controlled.
