Objective: Suicide is the single largest cause of premature death among individuals with schizophrenia. This report examines the relationship between positive or negative symptoms, illness subtype, and suicidal behavior among patients with schizophrenia and schizophrenia spectrum disorders in a long-term follow-up cohort.
Method: Based on index admission records, patients from the Chestnut Lodge Follow-Up Study with schizophrenia (N = 187), schizoaffective disorder (N = 87), schizophreniform disorder (N = 15), and schizotypal personality disorder (N = 33) were retrospectively assessed with the Positive and Negative Syndrome Scale, classical subtype criteria, and criteria for the deficit syndrome. Completed suicide, suicide attempts, and suicidal ideation during the follow-up period (average = 19 years) were ascertained by means of interviews with patients and/or surviving relatives.
Results: Over the follow-up period, 40% of the patients reported suicidal ideation, 23% reported suicide attempts, and 6.4% died from suicide. Patients dead from suicide had significantly lower negative symptom severity at index admission than patients without suicidal behaviors. Two positive symptoms (suspiciousness and delusions), however, were more severe among successful suicides. The paranoid schizophrenia subtype was associated with an elevated risk (12%) and the deficit subtype was associated with a reduced risk (1.5%) of suicide.
Conclusions: The impact of positive and negative symptoms on suicide risk has not been reported. These findings suggest that prominent negative symptoms, such as diminished drive, blunted affect, and social and emotional withdrawal, counter the emergence of suicidality in patients with schizophrenia spectrum disorders and that the deficit syndrome defines a group at relatively low risk for suicide. Prominent suspiciousness in the absence of negative symptoms defines a relatively high-risk group.