Participants with depression will be divided into two groups: those with normal BMD and those with low BMD. Depressed participants with normal BMD will be compared to a control group of healthy premenopausal women with normal BMD and followed for 36 months. Dual energy X-ray absorptiometry (DEXA) determinations will be made at months 6, 12, 24 and 36; bone turnover and endocrine parameters of depression will be