My 19 Year Old Daughter Runs Xc And Track On

My 19 year old daughter runs xc and track on the collegiate level. She does not get her period and recently had a bone scan to determine if she has low bone density. her spine is low and so her dr put her on the birth control pill to increase bone growth at her young and developing age. She is experiencing mild depression...hard to tell if this is a result of the pill or a situation which definitively affected her personal life. thoughts?