Empirical assessment of the self-medication hypothesis among dually diagnosed inpatients.

The aim of this study was to empirically determine the expected effects of drugs of abuse on the psychiatric symptoms of individuals dependent on alcohol and other drugs to assess the validity of the self-medication hypothesis, defined as motivation of patients to seek a specific drug for relief of a particular set of symptoms. Eight-three inpatients in a large metropolitan hospital with an axis I diagnosis of one drug dependence and an axis II diagnosis of personality disorder completed the Hopkins Symptom Checklist-Revised (HSCL-90-R) and the Neuropsychological Impairment Scale (NIS). They also reported the effect of their drug of choice on each of the symptoms included in both tests. Heroin addicts reported that heroin improved some of their psychiatric symptoms and all of their cognitive dysfunctions. Both cocaine and alcohol users reported that their drug of choice worsened their psychiatric and cognitive symptoms. No relationship was found between frequency or severity of symptoms and drug choice. We concluded that attempts at self-medication may have occurred among heroin addicts, but were unlikely among alcoholics and cocaine addicts. We found no evidence in support of the self-medication hypothesis as a necessary reinforcer of continued drug use.