Methylphenidate and haloperidol in children. Effects on attention, memory, and activity.

Twenty-four hyperactive or unsocialized-aggressive children participated in an exploratory double-blind crossover study comparing the cognitive effects of methylphenidate hydrochloride (0.3 mg/kg), two doses (0.25 and 0.05 mg/kg) of haloperidol, and inert placebo. Each subject received each of four drug conditions, drug order being randomized by a Latin square design. At the end of each 18-day trial period, attention, immediate recognition memory, reaction times, and seat activity were tested. While drug effects were small, methylphenidate and, to a lesser extent, the low dose of haloperidol, facilitated performance, whereas there was some suggestion that the high dose of haloperidol may have caused a slight deterioration in performance. These results are contrasted with effects on social behavior where the latter improved behavior. No differences attributable to diagnosis were found.