Case-control study of the relationship of depressive symptoms to suicide in a community-based sample of individuals with schizophrenia in China

Kasckow, John; Liu, Nancy; Haas, Gretchen L.; Phillips, Michael R.

doi:10.1016/j.schres.2010.02.1056

« Previous Next »Schizophrenia Research
Volume 122, Issue 1 , Pages 226-231, September 2010

Case-control study of the relationship of depressive symptoms to suicide in a community-based sample of individuals with schizophrenia in China

John Kasckow
- VA Pittsburgh Health Care System MIRECC and Behavioral Health Service; 7180 Highland Dr., Pittsburgh, PA 15206, USA
- Western Psychiatric Institute and Clinics, University of Pittsburgh Medical Center, 3811 O'Hara St. Pittsburgh, PA 15213, USA
- Corresponding author. VA Pittsburgh Health Care System, Behavioral Health, 7180 Highland Dr, Pittsburgh, PA 15206, USA. Tel.: +1 412 954 4344; fax: +1 412 954 5035.
Nancy Liu
- WHO Collaborating Center for Research and Training in Suicide Prevention, Beijing Hui Long Guan Hospital, Beijing, China
- Department of Psychology, University of Nebraska-Lincoln, Lincoln, Nebraska, USA
Gretchen L. Haas
- VA Pittsburgh Health Care System MIRECC and Behavioral Health Service; 7180 Highland Dr., Pittsburgh, PA 15206, USA
- Western Psychiatric Institute and Clinics, University of Pittsburgh Medical Center, 3811 O'Hara St. Pittsburgh, PA 15213, USA
Michael R. Phillips
- WHO Collaborating Center for Research and Training in Suicide Prevention, Beijing Hui Long Guan Hospital, Beijing, China
- Departments of Psychiatry and Epidemiology, Columbia University, New York, USA

Received 28 November 2009; received in revised form 8 February 2010; accepted 15 February 2010. published online 15 March 2010.

Abstract

Backgound

Suicide is the leading cause of premature death among people with schizophrenia. Most studies on suicide and schizophrenia report an associated depression history, but they are based on clinical samples from mostly western countries.

Methods

We conducted a secondary analysis of 74 suicides (cases) and 24 accidental deaths (controls) among persons with schizophrenia identified in a national psychological autopsy study in mainland China using the Chinese version of the Structured Clinical Interview for DSM-IV. A ‘depression symptom severity score’ based on number, severity, and persistence of depressive symptoms 2weeks before death was derived from psychiatric interviews with 2 informants; determination of a ‘dysfunction due to depressive symptoms score’ was based on informants' reports about effects of depressive symptoms on decedents' functioning in the month before death. In addition, the mean number of negative life events was determined along with the effect of the events on the decedent. Comparison of the measures made for cases and controls were made by univariate analysis followed by adjustments using the False Discovery Rate.

Results

Compared to persons with schizophrenia who died by accident, those who died by suicide were more likely to have a recent DSM IV diagnosis of major depression, the symptom of depressed mood, thoughts of death and a prior suicide attempt. In addition, those who died by suicide were more likely to have a higher overall depression severity score and greater dysfunction due to depressive symptoms.

Discussion

This community-based study of individuals with DSM-IV schizophrenia who died by suicide in a non-western culture extends findings from clinical studies in western cultures providing data on the importance of depressive symptoms as risk factors for suicide in schizophrenia in a low income rural setting. These findings underline the importance of routine screening for depressive symptoms among patients with schizophrenia.

Keywords: Depression, Suicide, Schizophrenia, China, Psychological autopsy