Association between medication and risk of suicide, attempted suicide and death in nationwide cohort of suicidal patients with schizophrenia

Abstract

Purpose: Mortality among schizophrenia patients is substantially higher than in the general population. The aim of this study was to investigate, in a nationwide cohort of suicidal schizophrenic individuals, how the risks of suicide, severe suicide attempts and death are associated with usage of antidepressant or antipsychotic treatment.

Methods: The study population included all individuals in Finland who were hospitalised with a diagnosis of attempted suicide between 1 January 1997 and 31 December 2003, who also had at least one hospitalisation due to schizophrenia diagnosis (ICD-10 F20), and were at least 16 years old when the index hospitalisation began. Cox's proportional hazards modelling and Bayesian intensity estimation were used in the analysis.

Results: There were 1611 patients with a mean follow-up time of 4.3 years. Current use of antipsychotics was associated with decreased mortality due to suicide (HR 0.52, 95% CI 0.34-0.81, p = 0.004), but no significant decrease in mortality was observed during current use of antidepressants (0.66, 0.41-1.08, p = 0.099), when compared to past use. In more detailed analysis when current users were compared to non-users, olanzapine, and mixed use of antipsychotics, were associated with reduced all-cause mortality, and mixed use also with reduced risk of suicide mortality. Current use of citalopram was associated with decreased all-cause and suicide mortality.

Conclusions: In a population of suicidal schizophrenic individuals antipsychotic medication, treatment was associated with lower mortality from suicide and all-causes. Antidepressive medication was associated with lower all-cause mortality when used in combination with antipsychotics.