Methylphenidate effects in learning disabilities. Psychometric changes.

Sixty-one children of average intelligence with appreciable learning lags, but no behaviour disorders, received placedo or methylphenidate hydrochloride for a 12-week period. Methylphenidate was instrumental in improving performance on many psychological tests, but did not affect performance on standardized achievement tests. None of the patient characteristics investigated was stringly predictive of drug effect. Methylphenidate seems to have a specific effect on visualmotor processes, which in turn positively affect performance tasks, but not verbal tasks. Under the conditions of this study, methylphenidate treatment alone did not emerge as a useful agent for the amelioration of reading performance, although the data provide evidence for stimulation effects on children's cognitive functions.