Antipsychotics and risk of natural death in patients with schizophrenia

Abstract

Background: Research on antipsychotics and early mortality in schizophrenia has arisen from Western countries and results show that mortality from natural causes is obviously increased in schizophrenia. China, differs largely from Western countries in health and social welfare systems, and Asian patients are more susceptible to side-effects and might require less antipsychotics than their Western counterparts. We, therefore, investigated the association between antipsychotic use and increased mortality from natural causes among patients with schizophrenia in China. Methods: We conducted a population-based nested case-control study using patients' hardcopy archives obtained from the Severe Mental Health Disorder Systems of Chengdu between January 1, 2006 and December 31, 2013. We identified all schizophrenic patients aged 18-65 years who died of natural causes in 2013 (N=157), and their age- and gender-matched controls (N=444). Results: Antipsychotic use was more frequent in controls than in cases (59.9% vs 32.5%). Risk of death decreased significantly in those receiving antipsychotic monotherapy (adjusted odds ratio=0.27, 95% CI=0.16-0.46) and antipsychotic polypharmacy (adjusted odds ratio=0.29, 95% CI=0.12-0.70) than antipsychotic-free patients. Compared with monotherapy, antipsychotic-free treatment was associated with prominently increased mortality (adjusted odds ratio=3.64, 95% CI=2.18-6.08). When stratified by age and gender, the results remained unchanged. Conclusion: Antipsychotic monotherapy significantly decreased mortality from natural causes in schizophrenic patients while antipsychotic polypharmacy did not contribute to the excess mortality and deserves further clarification. We need to improve the physical health of schizophrenic patients and promote health education among community mental health staff and primary caregivers.

Keywords: antipsychotics; mortality; odds ratio; polypharmacy; schizophrenia.

Figure 1

Clinical characteristics of the 601 patients with schizophrenia. Notes: (A) The number of concomitant antipsychotics use in the case and control group (0: no antipsychotic use；1: monotherapy；2: 2 or 2 more antipsychotic use). (B) The patient number of comorbidity in the case and control group (0: no comorbidity; 1: have comorbidity). (C) The patient number of benzhexol use in the case and control group (0: no benzhexol use; 1: benzhexol use).