Treatment of mental illness in American adolescents varies widely within and across areas.

Many mental health disorders first manifest in adolescence, and early treatment may affect the course of the disease. Using a large national database of insurance claims, this study focuses on variations in the type of care that adolescent patients receive when they are treated for an initial episode of mental illness. We found large variations in the probability that children receive follow-up care and in the type of follow-up care received across zip codes. We also found large variations in the probability that children receive drug treatments that raise a red flag when viewed through the lens of treatment guidelines: Overall, in the first 3 mo after their initial claim for mental illness, 44.85% of children who receive drug treatment receive benzodiazepines, tricyclic antidepressants, or a drug that is not Food and Drug Administration-approved for their age. On average, these children are 12 y old. While the supply of mental health professionals impacts treatment choices, little of the overall variation is explained by supply-side variables, and at least half of the variation in treatment outcomes occurs within zip codes. These results suggest that other factors, such as physician practice style, may play an important role in the types of treatment that children receive.