OBJECTIVE: To describe national annual prescribing patterns of stimulant, antidepressant, and antipsychotic medications to young people. METHODS: Prescriptions for three commonly prescribed psychotropic classes (stimulants, antidepressants, and antipsychotics) to young people aged 3-24 years were analyzed from the IMS LifeLink LRx National Longitudinal Prescription database (n = 6,351,482). Denominators were adjusted to generalize estimates to the U.S. POPULATION: Comparisons are presented of percentages filling >/=1 prescription of each medication class during the study year stratified by patient sex, age, and prescriber specialty. RESULTS: The total annual percentage of prescriptions filled by youth for any of the three medication classes was by age 3-5 years (0.8%), 6-12 years (5.4%), 13-18 years (7.7%), and 19-24 years (6.0%). Stimulant use was highest for older children (age 11 = 5.7%). Antidepressant use tended to increase with age and was highest for young adults (age 24 = 4.8%). Annual antipsychotic prescription percentages were lower than antidepressant or stimulant percentages for all age groups, with a peak in adolescence (age 16 = 1.3%). Annual stimulant and antipsychotic percentages for males were higher than corresponding percentages for females, but converged for young adults. Psychiatrists and child psychiatrists accounted for most of the prescriptions of antidepressants (22.2%-53.2%) and antipsychotics (51.7%-70%), but fewer of the stimulant prescriptions (30.4%-36.2%). CONCLUSIONS: The age and sex distribution of stimulants and antidepressants among young people is broadly consistent with known epidemiologic patterns of their established indications for attention-deficit/hyperactivity disorder, anxiety, and depression. The pattern of antipsychotics may reflect the heterogeneity of disorders and conditions treated with this medication class.