SUBSTANCE-ABUSE AND THE ONSET OF SCHIZOPHRENIA

Up to 60% of chronic schizophrenic patients are reported to abuse alco hol or drugs. This comorbidity raises the question whether one disorde r is a consequence of the other. With the structured interview ''IRAOS ,'' the onset and course of schizophrenia and substance abuse were ret rospectively assessed in a representative first-episode sample of 232 schizophrenic patients, information by relatives validated the patient s' reports. Alcohol abuse prior to first admission was found in 24%, d rug abuse in 14%-twice the rates in the general population. Alcohol ab use more often followed than preceded the first symptom of schizophren ia. Drug abuse preceded the first symptom in 27.5%, followed it in 37. 9%, and emerged within the same month in 34.6% of the cases. The study demonstrates a remarkable association between first-episode schizophr enia and substance abuse, but a unidirectional causality is not suppor ted, nor is a specific psychotic disorder in comorbid cases. (C) 1996 Society of Biological Psychiatry