What are the strongest predictors of suicidality in schizophrenia?
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• The lifetime risk of completed suicide in schizophrenia is 5%
• 25% to 50% of patients with schizophrenia have a suicide attempt during their lifetime
• There is a need to better understand categorical and continuous risk factors for suicidality in schizophrenia
• Cassidy and colleagues performed a systematic review and meta-analysis of risk factors for suicidal ideation, suicide attempts, and suicide (suicidality) in patients with schizophrenia
• They included cohort studies, case control studies, and cross-sectional studies
• The authors searched Pubmed, Web of Science, and EMBASE
• Inclusion criteria were dichotomous samples of patients with schizophrenia with and without suicidality; at least 70% of the study sample had a diagnosis of schizophrenia
• The authors first performed random-effects meta-analysis of any risk factor reported in 2 or more studies
• The authors tested for publication bias and performed sensitivity analyses to look at between-study heterogeneity
• They also performed meta-regression analyses to look at moderating effects of age, illness duration, geography, study design, and study quality on associations between risk factors and suicidality
• The authors identified 96 studies with 80,488 participants that met study inclusion criteria
• Among categorical variables: poor (treatment) compliance, history of suicide attempt, hopelessness, and male sex were significant predictors of completed suicide in the primary and sensitivity analyses
• Among continuous variables: higher IQ and shorter illness length were significant predictors of completed suicide in the primary and sensitivity analyses
• Age, male sex, geography, and study quality score accounted for between-study heterogeneity
• Among categorical variables: physical comorbidity; history of depression; family history of psychiatric illness and suicide; Caucasian race; and history of tobacco, alcohol, or drug use were significant predictors of suicide attempt in the primary and sensitivity analyses
• Among continuous variables: greater number of psychiatric hospitalizations and Beck Depression Inventory (BDI) score were significant predictors of suicide attempt in the primary and sensitivity analyses
• No categorical risk factors were significantly associated with suicidal ideation
• Among continuous variables: Hamilton Depression scale (HAM-D) and BDI score, Positive and Negative Syndrome Scale general score, and number of psychiatric hospitalizations were higher in patients with suicidal ideation in the primary and sensitivity analyses
In cohort studies:
•Male sex, history of suicide attempts, history of tobacco use, younger age and age of illness onset, and shorter disease length were predictors of suicide
•History of suicide attempts, history of alcohol use, family history of psychiatric illness, and younger age of illness onset were predictors of suicide attempt
• This was the first meta-analysis of risk factors associated with suicidal ideation and attempts in schizophrenia
• The authors note that while causality cannot be inferred, findings strengthen the evidence for risk factors for suicidality in schizophrenia
• Clinicians can employ strategies to identify and target these risk factors
• Findings also inform potential preventive strategies to combat suicide in schizophrenia
1. Hor K, Taylor M. Suicide and schizophrenia: a systematic review of rates and risk factors. J Psychopharmacol. 2010;24:81-90.
2. Meltzer HY. Treatment of suicidality in schizophrenia. Ann NY Acad Sci. 2001;932:44-58.
3. Cassidy RM, Yang F, Kapczinski F, Passos IC. Risk factors for suicidality in patients with schizophrenia: a systematic review, meta-analysis, and meta-regression of 96 studies. Schizophr Bull. 2017. doi:10.1093/schbul/sbx131.