Comparative effectiveness of antipsychotics for risk of attempted or completed suicide among persons with schizophrenia

Objective
The objective of our study was to investigate the comparative effectiveness of antipsychotics for the risk of attempted or completed suicide among all patients with schizophrenia in Finland and Sweden.
Methods
Two nationwide register-based cohort studies were conducted, including all individuals with schizophrenia in Finland (n = 61 889) and Sweden (n=29 823). The main exposure was 10 most commonly used antipsychotic monotherapies; also, adjunctive pharmacotherapies were investigated. The main outcome measure was attempted or completed suicide, which was analyzed with within-individual models by comparing use and nonuse periods in the same individual to minimize selection bias. Sensitivity analyses included attempted suicide (hospitalization only) as an outcome.
Results
Compared with no use of antipsychotics, clozapine use was the only antipsychotic consistently associated with a decreased risk of suicidal outcomes. Hazard ratios (HRs) and 95% CIs for attempted or completed suicide were 0.64 (0.49–0.84) in the Finnish cohort and 0.66 (0.43–0.99) in the Swedish cohort. No other antipsychotic was associated with a reduced risk of attempted and/or completed suicide. Benzodiazepines and Z-drugs were associated with an increased risk of attempted or completed suicide (HRs: 1.29–1.30 for benzodiazepines and 1.33–1.62 for Z-drugs).
Conclusion
Clozapine was the only antipsychotic associated with decreased risk of attempted or completed suicide among patients with schizophrenia, and it should be considered as first-line treatment for high-risk patients.