Risk Factors for Suicidality in Patients With Schizophrenia: A Systematic Review, Meta-analysis, and Meta-regression of 96 Studies

The lifetime risk of suicide and suicide attempt in patients with schizophrenia are 5% and 25%-50%, respectively. The current meta-analysis aims to determine risk factors associated with suicidality in subjects with schizophrenia. We searched Pubmed, Web of Science, EMBASE, and the reference lists of included studies. Inclusion criteria were met if an article reported a dichotomous sample of patients with schizophrenia with suicidal ideation, attempted suicide, or suicide compared to patients without. We also performed a cohort study meta-analysis as a supplemental analysis. A total of 96 studies with 80 488 participants were included in our analysis. Depressive symptoms (P<.0001), Positive and Negative Symptom Scale (PANSS) general score (P<.0001) and number of psychiatric hospitalizations (P<.0001) were higher in patients with suicide ideation. History of alcohol use (P=.0001), family history of psychiatric illness (P<.0001), physical comorbidity (P<.0001), history of depression (P<.0001), family history of suicide (P<.0001), history of drug use (P=.0024), history of tobacco use (P=.0034), being white (P=.0022), and depressive symptoms (P<.0001) were the most consistent variables associated with suicide attempts. The first two were also significant in the cohort meta-analysis. Being male (P=.0005), history of attempted suicide (P<.0001), younger age (P=.0266), higher intelligence quotient (P<.0001), poor adherence to treatment (P<.0001), and hopelessness (P<.0001) were the most consistently associated with suicide. The first three were also significant in the cohort meta-analysis. Our findings may help with future development of preventive strategies to combat suicide. Future studies may combine the above-mentioned variables by using multivariate predictive analysis techniques to objectively stratify suicidality in schizophrenia.