DOES METHYLPHENIDATE INDUCE OVERFOCUSING IN HYPERACTIVE-CHILDREN

Investigated the effects of stimulant medication on allocation of atte ntion in the visual field The putative effect under investigation was the enhancement of focused attention, which in the extreme may produce overfocusing. The effects of two doses (0.3, 1.0 mg/kg) of methylphen idate were assessed in 22 children with attention-deficit hyperactivit y disorder on a cued reaction-time paradigm, using a double-blind, pla cebo-control, crossover design. Results indicated that only the high d ose had a specific effect on focused attention and this effect was del ayed relative to the more salient but nonspecific effect on overall ef ficiency of information processing. Task performance at high dose was related to concurrent clinical manifestations of intense concentration , but there was no evidence that methylphenidate produced overfocusing .