Subjective Effects of Methylphenidate
Methylphenidate (MPH) is one of the most widely prescribed psychotropic agents in the United States, and its increased use over the past two decades has been a source of growing controversy among scientists, clinicians, policy makers, and parents. This chapter highlights research and theory on the subjective effects of MPH and how their study can provide information addressing all these issues. The chapter begins by briefly reviewing the history of the clinical use of MPH and empirical work on the recent prescription trends of this drug. It then considers the question of what kinds of information the subjective effects of MPH can provide about both the clinical effects of the drug and its potential for abuse or misuse. The chapter reviews those studies that have evaluated the subjective effects of MPH in human participants, with emphasis on the methodological variation across studies in which these effects have been assessed. It emphasizes the measurement of MPH subjective effects in clinical samples of individuals with attention deficit/hyperactivity disorder (ADHD), including a recently completed study suggesting differential patterns of effects in this group versus healthy controls. Finally, the chapter provides an overview of potential neuropharmacological mechanisms.