Individuals with developmental disabilities (DD) exhibit the full range of psychiatric disorders found in their non-DD peers. Most estimates of the prevalence of serious psychiatric disorders, including personality disorders, range from 8% to 15% within the DD population.10 These numbers probably are underestimates, however, given a documented tendency to underdiagnose psychiatric problems in individuals with DD.11,12 Reiss13 found that psychologists were less likely to diagnose a debilitating fear in a population of individuals with mental retardation than in a population without DD. Additionally, obsessive-compulsive disorder in individuals with DD often remains undiagnosed.14 Some aggressive behavior problems in people with DD appear to be associated with psychiatric disorders.13 Individuals with DD and obsessive-compulsive disorder may become aggressive if prevented from engaging in their obsession.15–17

Individuals with DD also can manifest the full range of affective disorders.18,19 Numerous reports cite examples of both children and adults in whom bipolar disorder or depression has been diagnosed, who engage in various problem behaviors. These behaviors include self- injurious behavior (SIB), aggression, screaming, and property destruction.20

In sum, investigators have demonstrated that such problem behaviors as SIB or aggression may be symptoms of a wide variety of psychoses, neuroses, and affective disorders. A very careful analysis of behavior and its associated symptoms must be performed to determine the correct course of medical treatment.21–23

Adapted from: Sudhalter V. Problem behaviors in individuals with developmental disabilities. In: Devinsky O and Westbrook LE, eds. Epilepsy and Developmental Disabilities. Boston: Butterworth-Heinemann; 2001;165–174.
With permission from Elsevier (www.elsevier.com).
Reviewed and revised May 2004 by Steven C. Schachter, MD, epilepsy.com Editorial Board.