The biological basis for self-injury in the mentally retarded

Self-injurious behavior has presented a clinical and academic challenge to both behavioral and biomedical researchers. Recent advances in biomedical research suggest a number of specific biological bases for self-injury. This research was reviewed with regard to the possibility that a specific biological explanation for self-injury could be advanced. Deficiencies in biochemicals necessary for normal brain functioning, inadequate neurological development of the central nervous system, isolation and pain related experiences early in development, altered neurological input particularly sensory irritation, neurological insensitivity to pain, and the body's ability to produce opiate-like substances (endogenous opiates) in response to pain and injury all offer leads as to the biological basis of self-injurious behavior. No single explanation has been definitively proven as a cause for self-injury in the retarded. However, consideration of behavioral treatment approaches in combination with biological explanations, especially those related to the biochemistry of pain, may provide the opportunity for important breakthroughs in the understanding and successful elimination of self-injurious behavior.