Positive and negative syndrome typology in schizophrenic patients with psychoactive substance use disorders

Our objective was to begin to elucidate the interrelationship between psychoactive substance use disorders (PSUD) and schizophrenia in patients who concurrently have both disorders. A series of 29 psychiatric inpatients with concurrent Research Diagnostic Criteria (RDC)-diagnosed schizophrenia and PSUD (PSUD/S patients) were evaluated with rating inventories including the Schedule for Assessment of Negative Symptoms (SANS) and the Schedule for Assessment of Positive Symptoms (SAPS). Subjects had chronic schizophrenia with a mean duration of 9.9 years, and virtually all (93.1%) regularly abused cocaine and alcohol, as well as marijuana. The majority of subjects (58.6%) had mixed-syndrome typology, as defined by Andreasen; 24.1% had negative syndrome; and 16.7% had positive syndrome. Contrary to predictions, negative-syndrome PSUD/S patients had fewer years post-onset of schizophrenia than those patients with positive syndrome. In contrast to other schizophrenic patients, in whom the trajectory of symptoms is believed to change from a predominance of positive symptoms to a predominance of negative symptoms over the course of illness, in a sample of patients with comorbid PSUD/S we found the opposite pattern. This may have implications in the development of PSUD among certain schizophrenics, and may help to guide both psychiatric and substance abuse treatment of such patients.