In contrast to antiresorptive treatments, there are also anabolic agents; these stimulate bone growth, with currently the only approved anabolic for systemic use being parathyroid hormone (PTH) [104]; this treatment stimulates osteoblasts, thus promoting increased BMD, although PTH has been associated with side effects such as headaches, dizziness, joint pain, depression [105] and hypercalcemia [106]. The gene discussed is PTH; the disease is major depressive disorder.