Dual diagnoses. Psychiatric disorders in developmental disabilities.

A high prevalence of psychiatric illness exists in persons with mental retardation. Among children with mild to moderate retardation, psychiatric illnesses resemble those seen in the general population. Major affective disorders, ADHD, and conduct disorder are common and respond to the same interventions used in children without mental retardation. Persons with severe to profound retardation are more likely to engage in stereotypies and self-injurious behaviors. In addition, certain specific syndromes associated with mental retardation present with particular neurocognitive, behavioral, and psychiatric profiles. Common examples are fetal alcohol syndrome, Down syndrome, fragile X syndrome, and Rett syndrome. Specific challenges exist for pediatricians who diagnose and treat patients with mental retardation and psychiatric illness. The child's impaired ability to communicate his or her thoughts and feelings with words makes clinical history taking difficult. The clinician must frequently rely on the observation of family members and teachers. An understanding of developmental profiles and interpersonal, peer, and family dynamics is important. Specific behaviors must be targeted and realistic objectives set in treatment planning, which may include psychotherapy, medication, behavior management techniques, and rehabilitation therapy.