Never Enough: The Neuroscience and Experience of Addiction

by Judith Grisel

The stimulants methylphenidate (Ritalin) and amphetamine (Adderall) have been effectively used to treat attention deficit hyperactivity disorder (ADHD) for almost sixty years. ADHD diagnoses are common: in the United States, about 12 percent of children over age four have a diagnosis for an attention deficit disorder, and most of these, about four million, are treated with stimulants each day.1 The difference between those with ADHD diagnoses and those without is quantitative: for those with the disorder, drug treatment brings their cognition within normal range. Nonetheless, the high rates of use of these drugs in clinical populations, as well as by many in the normal range looking for enhancement rather than treatment, have led to concerns about possible long-term effects, and especially to the fear that the treatment may increase the risk for subsequently developing addiction. Given what we know about adaptation, it seems especially plausible because these drugs increase dopamine levels throughout the brain, including in the nucleus accumbens. In general, though, the research suggests that when these drugs are used as prescribed for ADHD, chronic exposure to them does not have lasting effects on behavior or cognition.2