Fourteen-year prospective follow-up study of positive and negative symptoms in chronic schizophrenic patients dying from suicide compared to other causes of death.

BACKGROUND: Several trials have suggested that negative symptoms are inversely correlated with suicidal risk in schizophrenic patients. This fourteen-year follow-up study compared the positive and negative symptoms of schizophrenic patients who died from suicide to those of subjects dying from other causes. SAMPLING AND METHODS: From 1991 to 1995, 150 patients meeting the research diagnostic criteria for chronic schizophrenia were assessed. On inclusion, they completed the Physical Anhedonia Scale as well as the Beck Depression Inventory, and the positive and negative symptoms were rated by the Positive and Negative Syndrome Scale.
RESULTS: During the 14-year follow-up, 8 patients committed suicide, while 17 died from other causes. The suicide victims had a shorter duration of illness and a higher level of education compared to those who died from other causes. The proportion of 'negative' subjects, according to the composite index of the Positive and Negative Syndrome Scale, was lower among the suicide victims than among the participants who died from other causes. All these differences were significant. The rate of deficit syndrome (0%) among the suicides was lower than that (23.5%) of the other subjects. The scores on the Physical Anhedonia Scale and of the social withdrawal item of the Beck Depression Inventory were higher in the suicides than in the subjects who died from other causes.
CONCLUSIONS: These findings suggest that negative symptoms and notably deficit-negative symptoms could be associated with a low risk of suicide. In this study, the link between anhedonia and high risk of suicide in schizophrenic patients indicates that this symptom could be more closely related to depression than to negative symptoms. Copyright 2009 S. Karger AG, Basel.