Psychoactive substance use diagnoses among psychiatric in-patients

To estimate the prevalence and possible under-diagnosing of substance use disorders and to consider factors that might influence diagnosing of substance use disorders.

Data collected from case records and PSE interviews of psychiatric in-patients from 12 psychiatric departments in Denmark admitted during October 1996 were compared with data from the Danish Psychiatric Register.

A substantially lower prevalence of substance use diagnoses were found in the register (26.1%) than in the research data (50.0%). A high prevalence of co-occurrence between substance use disorders and mental disorders other than substance use disorders was found (37.3%). In the majority of cases knowledge of the substance use disorders was present in the case records, although they had not resulted in a diagnosis.

The under-diagnosis of substance use disorders is due not only to concealed diagnostic signs and symptoms but also to an under-diagnosis by the psychiatrists, in spite of the fact that information on the substance use was accessible.