Emerging evidence suggests that serotonin plays a central role in bone metabolism. For example, preclinical experiments have shown that bone cells express the serotonin transporter and a variety of functional serotonin receptors whose activity modulates bone turnover. Epidemiologic studies have linked SSRIs to reduced bone mineral density and increased fracture risk in the elderly. SSRIs are widely used in youths to treat a number of psychiatric disorders. However, while their short-term efficacy and safety have been established, their long-term safety remains little investigated.