Failure of naltrexone hydrochloride to reduce self-injurious and autistic behavior in mentally retarded adults. Double-blind placebo-controlled studies

Arch Gen Psychiatry. 1995 Sep;52(9):766-73. doi: 10.1001/archpsyc.1995.03950210060011.


Background: It is hypothesized that self-injurious behavior (SIB) and symptoms of autism may be due to overactivity in some opioid systems in the brain. We examined the efficacy and safety of naltrexone hydrochloride, an opioid antagonist, in the treatment of SIB and autism in mentally retarded adults.

Method: Thirty-three mentally retarded adults with autism and/or SIB participated in double-blind, placebo-controlled crossover studies. Active treatment was first a single 100-mg dose of naltrexone hydrochloride. Subsequently, 19 subjects were treated with 50 mg/d and 14 with 150 mg/d of naltrexone hydrochloride for 4 weeks. The outcome was assessed by means of direct observations (n = 11) and on the basis of scores on a list of target behaviors, the Aberrant Behavior Checklist, and the Clinical Global Impression Scale.

Results: Thirty-two subjects (seven with autism, 16 with autism and SIB, and nine with SIB) completed the trial. Naltrexone treatment failed to have therapeutic effects on SIB and autism. On the contrary, naltrexone increased the incidence of stereotypic behavior on the Aberrant Behavior Checklist, and the care staff evaluated the effect of the 50-mg/d treatment as being significantly worse than that of the placebo treatment as measured by the Clinical Global Impression Scale.

Conclusion: Our findings suggest that naltrexone has no clinical value for a broad group of mentally retarded subjects with SIB and/or autism.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Autistic Disorder / drug therapy*
  • Autistic Disorder / epidemiology
  • Autistic Disorder / psychology
  • Comorbidity
  • Cross-Over Studies
  • Double-Blind Method
  • Drug Administration Schedule
  • Female
  • Humans
  • Incidence
  • Intellectual Disability / epidemiology
  • Intellectual Disability / psychology*
  • Male
  • Middle Aged
  • Naltrexone / therapeutic use*
  • Placebos
  • Psychiatric Status Rating Scales
  • Self-Injurious Behavior / drug therapy*
  • Self-Injurious Behavior / epidemiology
  • Stereotyped Behavior / drug effects
  • Treatment Outcome


  • Placebos
  • Naltrexone