The Addiction Severity Index as a predictor of the use of mental health care.

The Addiction Severity Index (ASI) has been extensively used in the United States and Europe as an indicator of the problems of substance abuse patients. Several studies have shown the ASI to be a reliable and valid instrument, but lately doubt has arisen regarding its validity and reliability. The article focuses on a specific scale of the ASI--the Psychiatric Status scale--and its strength in predicting the use of mental health care. A group of 1,027 heroin patients in Rotterdam, the Netherlands, who participated in a methadone program were the subjects. Three indices have been used: the evaluation index, the clinical index, and the composite scores. It appears that no matter which indices are used, the Psychiatric scale does discriminate between those who will have contact with mental health care and those who will not. However, the percentage of false positives is high. None of the indices predicts the intensity and duration of the mental health care treatment.