Hundreds of clinical studies, most using rigorous research methods, have been published on psychostimulant medications since their initial experimental use on children more than 50 years ago. The research supports the fact that, like all medications, psychostimulants have potentially serious side effects that must be carefully monitored by the prescribing physician, as well as the patient and family.
These side effects can be loosely divided into transient, short-term effects (such as headaches, mild abdominal pain and rarely clinically significant increases in blood pressure and heart rate) and longer-term effects. These longer-term effects include:
Appetite suppression: this tends to stabilize after a few months. It can be minimized by coordinating the timing of medication and meals and allowing for "catch-up" eating during periods of medication.
Growth suppression: recent long-term studies of large cohorts of adults who were treated with psychostimulants as children suggest expected adult height is not compromised, especially if "drug holidays" are employed to allow for catch-up growth.
Sleep disturbances: recent studies suggest that sleep patterns may actually be improved by psychostimulant use in children with baseline sleep problems commonly related to their underlying ADHD. When sleep initiation problems do occur, they can often be lessened by dosage adjustments.
Concerns about delayed long-term side effects, such as a higher incidence of substance abuse, have not been supported by long-term follow-up studies of adults treated for ADHD in childhood and adolescence.
All of these potential health risks must, of course, be weighed against the potential benefits of psychostimulant use. Although psychostimulants are not effective in all children with documented ADHD, about 75 to 80 percent of treated children experience improvements in attention span and frustration tolerance and decreases in distractibility, disruptive and impulsive behavior, physical activity level/fidgetiness, and oppositional and aggressive behavior. Motivation, especially in the performance of "boring" tasks, and overall compliance usually increase significantly.
Improvement in these factors often results in improvement in interpersonal skills and social behaviors, which in turn decreases the negative feedback children with ADHD often receive from both peers and adults. Overall enhanced self-esteem often results from more satisfying peer relations and the improved school performance that often follows the improvements in accuracy and efficiency in their academic work.
Although recent studies document long-term positive gains in such areas as social skills and self-esteem in adulthood, psychostimulants are clearly not a panacea for individuals with ADHD. Long-term improved academic achievement is probably not accomplished by use of medication alone, but rather by a combination of treatment modalities: behavior therapy, educational measures, psychotherapy, group and family therapy etc., which enhance and support the effects of medication.
Comorbid conditions, such as conduct disorder and depression, especially if unrecognized and untreated, also very significantly affect long-term prognosis in individuals with ADHD.