Suicidality and use of psychotropic medications in patients with schizophrenia: a prospective cohort study

The lifetime prevalence of suicide is around 5% in patients with schizophrenia. Non-adherence to antipsychotic medication is an important risk factor, but prospective studies investigating joint effects of antipsychotic drugs, antidepressants, and benzodiazepines on suicidality are scarce. We aimed to investigate how use and non-use of psychotropic medications are associated with suicidality in schizophrenia.

An open cohort study followed all patients consecutively admitted to a psychiatric acute unit during a 10-year period with a diagnosis of schizophrenia (n = 696). Cox multiple regression analyses were conducted with use of antipsychotics, antidepressants, and benzodiazepines as time-dependent variables. Adjustments were made for age, gender, depressive mood, agitated behavior, and use of alcohol and illicit substances.

A total of 32 (4.6%) suicide events were registered during follow-up. Of these, 9 (28%) were completed suicides and 23 (72%) were attempted suicides. A total of 59 (8.5%) patients were readmitted with suicidal plans during the follow-up. Compared to non-use, use of antipsychotics was associated with 70% lower risk of attempted or completed suicide (adjusted hazard ratio [AHR] = 0.30, p < 0.01, CI 0.14-0.65) and 69% reduced risk of readmission with suicidal plans (AHR = 0.31, p < 0.01, CI 0.18-0.55). Use of prescribed benzodiazepines was associated with 126% increased risk of readmission with suicidal plans (AHR = 2.26, p = 0.01, CI 1.24-4.13).

Adherence to antipsychotic medication is strongly associated with reduced suicidal risk in schizophrenia. The use of prescribed benzodiazepines was identified as a significant risk factor for being readmitted with suicidal plans.