Methylphenidate and cognitive performance

Methylphenidate (MPH) is the active ingredient of stimulant drugs that are frequently prescribed to individuals with Attention Deficit / Hyperactivity Disorder (ADHD). In this chapter we examine the effect of MPH on different aspects of cognitive performance. The reviewed findings suggest that MPH effectively enhances sustained attention, response inhibition, and working memory capacities; yet not only for individuals with ADHD, but also for those without ADHD. Individuals who seem most affected by MPH are those with a profile of low task performance in the given task. This occurs most strongly under challenging task conditions. We further review the long term consequences of chronic usage of MPH. The findings concerning this issue are less conclusive, but there is no evidence of considerable physical harm or risk of subsequent abuse as long as dosage remains low. Still, the beneficial effects of taking MPH seem to be limited to the treatment period.