Alcohol and cocaine abuse comorbidity in schizophrenia

The prevalence of alcohol and cocaine abuse in schizophrenia has been established to be substantially higher than in the general population, but little is known about this increased vulnerability. The present research was designed to evaluate three hypotheses regarding the mechanisms by which the psychopathology of schizophrenia might lead to an increased vulnerability of alcohol and cocaine use disorders: (1) Schizophrenic individuals with a history of alcohol and cocaine use disorders will report significantly more use of alcohol and cocaine for social motives and will have higher levels of social drive (lower scores on social anhedonia); (2) Schizophrenic individuals with a history of alcohol and cocaine use disorders will report more coping motives for abusing alcohol and cocaine and will have higher levels of distress symptoms (i.e., depression and anxiety); and (3) Schizophrenic individuals with a history of alcohol and cocaine use disorders will report significantly more use of alcohol and cocaine for pleasure enhancement motives and will have higher capacity to experience pleasure (lower scores on physical anhedonia). Two groups of schizophrenic patients with different histories of substance use disorder were studied, one with a history of only alcohol and cocaine use disorders (n=19) and another with no lifetime history of alcohol or other drug use disorders (n=16). Results indicated that schizophrenic patients with a history of alcohol and cocaine use disorders were more likely to report having social, pleasure enhancement, and coping motives for using those substances, along with higher levels of distress symptoms such as depression and anxiety as compared to their non-abusing counterparts. However, findings for social and physical anhedonia revealed no significant differences between the two subject groups on these factors. Possible explanations were offered, along with indicated areas for future research.