Expectations and motives for substance use in schizophrenia.

This study examined the internal reliability of standardized measures of substance use expectancies and motives in a schizophrenia population (n = 70) and the relationship of these expectancies and motives to alcohol and drug use disorders. Internal reliabilities were uniformly high for the subscales of the expectancy and motive measures. Analyses of the relationship between substance use disorders and expectancies revealed strong substance-specific expectations. Alcohol expectancies were related to alcohol disorders but not to drug disorders; cocaine expectancies were related to drug but not to alcohol disorders; and marijuana expectancies were more strongly related to drug than to alcohol use disorders. In contrast, motives were related to substance use disorders, and self-reported substance use problems were related to expectancies and motives in a non-specific manner. These results suggest that expectancy and motive questionnaires developed for the primary substance abuse population may be valid for psychiatric populations. Research on motives and expectancies may help to clarify the functions of substance abuse in persons with schizophrenia.