Some withdraw and some swallow pills. Others drink heavily or are promiscuous. Some may destroy their true selves in an effort to be socially acceptable. Others strive to be fully feminine and fail. They aren't pretty enough or popular enough in just the right ways at the right times.
Some girls are depressed because they have lost their warm, open relationship with their parents.
All girls experience pain at this point in their development. If that pain is blamed on themselves, on their own families, it manifests itself as depression. The most severe symptom of depression is suicide. The Center for Disease Control in Atlanta reports that the suicide rate among children age 10 to 14 doubled from 1979 to 1996. Adolescence is a time when development and culture put enormous stress on girls.