Study to Determine Whether There Are Any Cognitive or Motor Effects From Taking the Medicine Risperidone.

Antipsychotics are fairly commonly used for managing certain psychiatric disorders that occur in childhood: schizophrenia, autistic disorder, delusional manic depressive disorder, bipolar disorder, conduct disorder, and disruptive behavior associated with mental retardation (Botteron \& Geller, 1998). They are also occasionally used for ADHD when more conventional treatments, such as psychostimulants and tricyclic antidepressants, have failed (Botteron \& Geller, 1998). Despite a helpful role for the antipsychotic medications in many childhood conditions, there is a persistent although poorly substantiated impression that these medicines cause "cognitive blunting" in children. This may be more commonly heard than seen in print, but we believe that it is the cause of considerable resistance to antipsychotic treatment by physicians and nonmedical professionals alike.

At the same time, the data supporting the notion of cognitive blunting by antipsychotic medicines is largely negative (although limited in amount) and frequently badly out of date (see Ernst, Malone, Rowan, George, Gonzales, \& Silva, 1998; Aman, 1984; Aman, Marks, Turbott, Wilsher, \& Merry, 1991). There are good theoretical reasons to believe that novel antipsychotics may have no effects on cognition or may actually enhance cognitive functioning, at least in some disorders (Borison, 1996; Meltzer, 1995; Stip, 1996). At least one study thus far has shown significantly improved cognitive performance in schizophrenic patients taking risperidone as compared with such patients taking high-potency classical antipsychotics or no treatment (Gallhofer, Bauer, Lis, Krieger, \& Gruppe, 1996).

Another source of resistance to the use of antipsychotic medicines with young people is the possibility that they may cause tardive dyskinesia. However, available data on the novel antipsychotics suggests that they are substantially safer than classical antipsychotics in this respect. Nevertheless, data are limited because of the newness of agents like risperidone.

Our laboratory at O.S.U. is unique because it has a sophisticated computer-controlled cognitive-motor test battery. O.S.U. is one of seven universities supported by NIMH as part of its network of Research Units on Pediatric Psychopharmacology ("RUPPs"). Recently, Dr. Mike Aman reviewed the available cognitive test systems on behalf of the Autism RUPP Group. From this exercise, it became quite clear to us that we maintain what is probably the world's best system for assessing the cognitive-motor effects of psychotropic drugs in children, especially children with developmental handicaps.

The experimental (research) portion of the treatment is to assess the effects of risperidone (Risperdal) on learning performance and motor movements in children. This study is looking at whether or not risperidone improves performance on certain cognitive-motor tasks. It is also looking to detect any negative side effects that the medicine has on children's body movements. Risperidone is often used to treat children with disruptive behaviors. This study will involve 18-20 children who are being treated by their own physicians with risperidone (for duration of 4 months or longer) for such behavior problems.