Placebo, Double-Blind Evaluation of Long-Term Naltrexone Treatment Effects for Adults with Mental Retardation and Self-Injury

This study evaluated the effects of naltrexone treatment for adults with mental retardation and self-injury across, a selection of dose levels, target behaviors, subjects and treatment phase durations. Statistical analysis of group results revealed a significant reduction in self-injury rate during naltrexone treatment. However, analysis of single-subject data indicated that only two of the nine subjects assessed demonstrated a significant and maintained suppression of self-injury rate associated with naltrexone treatment. The positive response of these two subjects occurred at the higher naltrexone dose level (100 mg/day) and appeared to be related to increased bioavailability of 6-beta-naltrexol, the active metabolite of naltrexone. Four subjects demonstrated naltrexone-related reductions in stereotypy, and one subject demonstrated naltrexone-related increases in adaptive material interaction. Given the wealth of previous research on naltrexone treatment of self-injury, present findings are discussed in relation to those of previous studies that have found more positive results.