Studies have shown that some antipsychotic medications, including Risperdal, can increase prolactin levels in both adult and pediatric populations. Prolactin is a hormone made by the central nervous system. The main function of prolactin is to regulate lactation in females. However, having too much prolactin over time can interrupt bone mineral accrual and a decrease in bone density. Since peak bone mass is reached during adolescents, this is a key determinant of a lifetime risk of osteoporosis. On the other hand, there ahve been no reports of increased prolactin using Abilify. In fact, in adults Abilify has been shown to normalize or even lower prolactin levels. In this study, we will compare the amount of prolactin and bone mineral density of adolescents who take Risperdal or Abilify with bone mineral density of adolescents who do nto take antipsychotic medications. We will also compare the amount of prolactin and bone mineral density of adolescents who take Risperdal with those who take Abilify. This study will also help us to learn about the relationship between medications, prolactin levels, sex steroids, and bone formation markers in adolescents.