Effects of naloxone and naltrexone on self-injury: a double-blind, placebo-controlled analysis.

The effects of naloxone hydrochloride (Narcan) and naltrexone hydrochloride (Trexan) on the pervasive self-injury of a 12-year-old autistic and mentally retarded girl were examined. Using separate multiple schedule (A1/B/B') and withdrawal (A-B-A1B-A1) single-subject experimental designs, we investigated the effects of both opiate antagonists in serial fashion under double-blind, placebo-controlled conditions. Results of the two studies showed that self-injury increased during the naloxone trial, whereas a decrease to near zero rates of self-injury was observed following treatment with naltrexone. The differential effect produced by the two drugs was discussed in terms of drug half-life and the operant conditioning theory of extinction. Follow-up data showing near zero rates of self-injury for 22 months following the conclusion of active treatment with naltrexone indicated that the intervention produced a durable result.