Brief report: comorbid psychiatric disorders of autistic disorder.

There are several medical conditions that have been recognized with relatively high frequency in individuals with Autistic Disorder (AD). About 30% of people with AD also have seizure disorders; 2-5% have fragile X syndrome; and 1-3% have tuberous sclerosis. In addition to these coexisting medical conditions, many autistic individuals also develop other behavioral and/or psychiatric symptoms in addition to the core autistic symptomatologies (i.e., impairment in social interaction, impairment in communication, and restricted, repetitive and stereotyped patterns of behavior, interests, and activities), that may be considered clinical manifestations of comorbid psychiatric disorders. The additional behavioral and/or psychiatric symptoms have been described by many investigators. Rutter, Greenfield, and Lockyer (1967) reported that among the 63 children with Infantile Psychosis, 48% were hyperkinetic at the time of first hospitalization, 43% had morbid preoccupation, 37% had obsessive phenomena, 70% had stereotyped mannerism, 25% had self-injury, and 60% had anxiety or fear. Simons (1974) reported that compulsive behavior was observed in every child with a clear-cut diagnosis of autism. Ando and Yoshimura (1979) reported that among the 47 autistic children (age range 6-14 years), 36% had hyperactivity; 68% had stereotyped behavior; 43% had self-injury; and 17% had fear. In a follow-up study of autistic adult males, Rumsey, Rapoport, and Sceery (1985) reported that 86% of these males continued to demonstrate stereotyped, compulsive behaviors, including arranging objects and other objects, and phonic tics. In a study of reliability and diagnostic validity of the Autism Diagnostic Interview (ADI) in 16 autistic subjects (mean age = 13.26 years, SD = 3.38), Le Couteur et al. (1989) reported that 73% of