To identify factors associated with suicide attempts using data from a large, 3-year, multinational follow-up study of schizophrenia (SOHO study).

All baseline characteristics of 8,871 adult patients with schizophrenia collected in patients included in the SOHO study were included in a GEE logistic regression post-hoc analysis comparing patients who attempted suicide during the study with those who did not.

A total of 384 (4.3%) patients attempted or committed suicide. The risk factors that resulted statistically associated with suicide attempt were a lifetime history of suicide attempts (OR 3.6 [95% CI 2.8, 4.6; p< 0.0001]), suicide attempts in the last 6 months (OR 2.5 [95% CI 1.8, 3.4; p< 0.0001]), prolactin-related side effects (OR 2.0 [95%CI 1.4, 2.9; p=0.0002]), CGI depression (OR 1.2 [95% CI 1.1, 1.3; p=0.0004]) and history of hospitalization for schizophrenia (OR 1.4 [95% CI 1.1, 1.8; p=0.009]).

In view of the observational design of the study and the post-hoc nature of the analysis, the identified risk factors should be confirmed by ad-hoc specifically designed studies.