Review ArticleAutism in mental retardationGhaziuddin, MohammadAuthor Information Correspondence to Mohammad Ghaziuddin, Division of Child Psychiatry, University of Michigan Medical Center TC 0390, 1500 East Medical Center Drive, Ann Arbor, MI 48109-0390, USA e-mail: firstname.lastname@example.org Current Opinion in Psychiatry: September 2000 - Volume 13 - Issue 5 - p 481-484 Buy Abstract There is a close relationship between autism and mental retardation. About three-quarters of people with autism also suffer from mental retardation of varying degree. Although most cases of autism are idiopathic in nature, approximately 10-25% are associated with known medical conditions, most of which involve mental retardation syndromes. Autism occurs more commonly with some conditions (such as tuberous sclerosis and fragile X syndrome) than with others (such as Down's syndrome and cerebral palsy). The present review examines recent research focusing on the comorbidity of autism with mental retardation. Association of autism with certain mental retardation syndromes is discussed, and the need for further research is emphasized. © 2000 Lippincott Williams & Wilkins, Inc.