F1 shows the distribution of the ADHD-related visits in 1995 for three physician specialties: primary care (general and family practice, adolescent medicine, pediatrics, geriatric medicine and internal medicine); psychiatry (child and adolescent psychiatry, psychiatry, and psychoanalysis); and other medical specialties, including neurology and child neurology. Visits to psychiatrists accounted for 12.4 percent of all ADHD-related visits, indicating that psychiatrists treat a substantial proportion of the childhood ADHD population. Some evidence suggests that the patients treated by psychiatrists constitute a more complex and more severely ill segment of the ADHD population (3). Therefore, it will be important to characterize the differences in patients seen by psychiatrists and primary care physicians as well as in the treatments they provide. In particular, efforts to improve the quality of care for children and adolescents with ADHD will need to take into account important differences in case mix and practice patterns.