Symptom Profile Patterns in Patients with Schizophrenia and Substance Abuse

We explored the relationship between symptoms of schizophrenia and the incidence of alcohol and substance abuse in 110 patients with schizophrenia diagnosed in accordance with DSM‐III. Symptoms were obtained through a structured interview and review of the case file. Substance abuse was a problem in 45.5% of these patients and was significantly more frequent in males than in females (69.1% versus 30.9%). Surprisingly, those engaging in substance abuse presently or in the past did not differ significantly from those free of substance abuse with respect to the length or number of psychiatric hospitalizations after we controlled out data for age by means of parietal correlation coefficients. Further analyses examined correlations of substance abuse with 87 symptoms relevant in diagnosing schizophrenia. Very few significant correlations were found and all of these were weak (phi coefficients ＜.40). Reports of present alcohol abuse were associated with delusional symptoms and patients presently abusing drugs more frequently showed symptoms of other mental illness in addition to their schizophrenia. We conclude that substance abuse is largely independent of symptoms of schizophrenia.