Differences in substance abuse patterns: multiple drug abuse alone versus schizophrenia with multiple drug abuse

To compare the lifetime consumption patterns of patients with schizophrenia and multiple substance abuse and multiple substance abusers without schizophrenia.

Two hundred and thirty in-patients of a specialized rehabilitation facility for young drug abusers were assessed with regard to their lifetime consumption patterns of 16 different classes of psychoactive drugs. While 110 patients had no diagnosis of a schizophrenic disorder, 120 patients had a comorbidity of multiple substance abuse and schizophrenia.

Comorbid patients reported a higher lifetime consumption of hallucinogens, whereas multiple substance abusers without schizophrenia showed a higher lifetime consumption rate of cocaine.

The differences found in lifetime consumption patterns between comorbid patients and substance abusers without psychotic disorder do not support the so-called self-medication hypothesis. Instead, the differences in lifetime consumption of certain drugs might be a result of lower social competence and standing in schizophrenic patients and lower ability to procure certain illicit drugs.