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

Abstract

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. 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. 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. 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.