An experimental design, (the pretest/posttest design) was used in this study to investigate the efficacy of substance abuse treatment using two instruments, the Addiction Severity Index (ASI) and the biopsychosocial assessment.

Fifty-six subjects admitted to the SYMBAS TEAM Substance Abuse Treatment Program were assessed during the initial stage of treatment using the biopsychosocial assessment and the ASI. Through the process of random selection, subjects were placed in one of two groups, an experimental group or a control group. Counselors working with the subjects in the experimental group had access to the results of the ASI and biopsychosocial assessment for treatment planning, and the counselors working with the subjects in the control group had access only to the results of the biopsychosocial assessment. At the end of treatment (gO-days), the subjects in both groups were re-assessed using the ASI to determine what differences, if any, occurred between the two sample groups.

Data was analyzed using descriptive statistics along with the Student test. Results revealed that there were no statistically significant differences between the two sample groups at the .05 alpha level. However, significant reductions between the ASI pre- and posttests mean scores were noted among several of the variables in both sample groups. Also, the counselors' perceptions of the ASI suggested that the ASI was preferred over the bippsychosocial assessment for treatment planning, because of its structure and the amount of time required to administer the instrument.