A review of the bidirectional relationship between psychiatric disorders and diabetes mellitus

The prevalence of type 2 diabetes is rising worldwide, including Saudi Arabia. Among patients with diabetes, 30% suffer from mental disorders, such as depression, schizophrenia, delirium, and substance misuse (for example, tobacco smoking). Moreover, these disorders appear to share a bidirectional relationship with diabetes. For example, the incidence of diabetes has been shown to be 2-4 times greater in patients with schizophrenia than in normal individuals; also, there is a known association between depression and diabetes. In this review, we focus specifically on the bidirectional relationship between diabetes and psychiatric disorders, including the effects of antipsychotic drugs.