Dopamine Antagonists Ameliorate the Dyskinesias, Aggression, and Inattention of Persons with Mental Retardation Referred to Psychiatric Clinics James Robert Brašic 1, 2 , Jacqueline Y. Barnett 2 , Richard Zelhof 3 , and Hugh Tarpley 3 1 Division of Nuclear Medicine, Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland 2 Department of Psychiatry, Bellevue Hospital Center and the New York University School of Medicine, New York, New York 3 Office of Mental Retardation and Developmental Disabilities of the State of New York, New York, New York Corresponding author: James Robert Brašic , M. D., M. P. H., Division of Nuclear Medicine, Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Johns Hopkins Outpatient Center, 601 North Caroline Street, Room 3245, Baltimore, Maryland 21287 -0807, United States of America, brasic@ jhmi.edu Abstract Background: Although dopamine antagonists are of ten administered to people with mental retardation, the neuropsychiatric effects are controversial. Objective: To characterize the effect of dopamine antagonists on movements and behaviors of persons with mental retardation. Method: Dyskinesias and behavioral problems are assessed in nine people with mental retardation referred to psychiatric clinics, including five men treated with dopamine antagonists in a dosage range equivalent to 67 to 220 mg chlorpromazine, and two men and two women who receive no medication during the preceding three months. Results: The nonmedicated subjects have higher levels of akathisia, stereotypies, tics, and other dyskinesias and lower global adaptive functioning. Utilizing the Mann-Whitney Test, nonmedicated subjects have more tics (P < .006), attention deficit disorder (P < .018), and overt aggression (P < .015); however, the Bonferroni correction for multiple comparisons renders all results nonsignificant. Conclusions: Dopamine antagonists ameliorate the dyskinesias, aggression, and inattention of some persons with mental retardation and behavioral problems. However, beneficial effects of dopamine antagonists must be weighed against adverse effects including withdrawal and tardive dyskinesias. Key Words: aggression, attention, dyskinesias, mental retardation, stereotypies, tics This research was supported by the Medical Fellows Program of the Consortium for Medical Education in Developmental Disabilities (CMEDD) of the Office of Mental Retardation and Developmental Disabilities (OMRDD) of the State of New York, the Essel Foundation, and the National Alliance for Research on Schizophrenia and Depression (NARSAD). This work was sponsored by the Department of Psychiatry at Bellevue Hospital Center and the New York University School of Medicine (German J Psychiatry 2001; 4: 9 -16). Received: 15.04.2001 Published: 15.06.2001 Introduction he beneficial and adverse effects of dopamine antagonists for individuals with mental retardation presenting at psychiatric clinics remain a topic of controversy. While multiple surveys in several locations have documented that 2 0 -51% of people with mental retardation and other developmental disabilities in the United States of America receive psychoactive medications ( Brašic et al., 1997c; 2000b), the efficacy of those pharmacologic interventions is uncertain. Although the benefits of the administration of dopamine antagonists to people with developmental disabilities are not established, there is evidence that people with developmental disabiliti es are at risk for adverse effects, including tardive and withdrawal dyskinesias ( Brašic and Bronson, T