Purpose of review: Excessive bone mineral density (BMD) loss has been associated with schizophrenia, but its mechanisms and clinical implications are less clear. The aim of this review was to summarize the risk of osteoporosis and bone fractures in schizophrenia patients. Moreover, we aimed to examine the impact of antipsychotic-induced hyperprolactinemia on bone metabolism.
Recent findings: Fifteen of 16 studies (93.8%) reported lower BMD or higher prevalence of osteoporosis in at least one region, or in at least one subgroup of schizophrenia patients compared with controls, but results were inconsistent across measured areas. Higher fracture risk was associated with schizophrenia in 2/2 studies (independently: n = 1), and 3/4 studies with antipsychotics. Reasons for this difference include insufficient exercise, poor nutrition, smoking, alcohol use, and low vitamin D levels. Altogether, 9/15 (60.0%) studies examining the relationship between antipsychotic-induced hyperprolactinemia and BMD loss found some effects of hyperprolactinemia. However, results were mixed, samples and effects were small, and only two studies were prospective.
Summary: Schizophrenia is associated with reduced BMD and fracture risk. Prevention, early detection, and intervention are required. The relative contributions of antipsychotic-related hyperprolactinemia and unhealthy lifestyle behaviors remain unclear, needing to be assessed in well designed, prospective studies, including bone turnover markers as intermediary endpoints.