Naltrexone attenuates self-injurious behavior in mentally retarded subjects.

The effect of naltrexone on the frequency of self-injurious behavior (SIB) was investigated in 6 male subjects with profound mental retardation. Following a double-blind placebo-controlled crossover design, naltrexone was administered in a dose of 50 mg once daily for 3 consecutive weeks. In 2 of 5 subjects, a significant decrease of SIB frequency could be demonstrated, and in 1, a tendency to a reduction was found. No effect on duration of restrain time was found in 3 subjects. These data suggest that disturbances of the endogenous opioid systems may be involved in the pathophysiology of SIB of certain patients.