Shared early life risk factors for schizophrenia and diabetes

A confluence of evidence supports associations between schizophrenia and both type 1 (DM1) and type 2 (DM2) diabetes. Outside of studies of snared genetic risk factors, other early life risk factors for schizophrenia and diabetes have not been reviewed. In this paper, we review maternal and paternal factors, birth factors, genetic factors, and other factors that may underlie both disorders, with DM1 and DM2 considered separately. We identified several risk factors common to schizophrenia and both DM1 and DM2, including nulliparity, gestational diabetes, preeclampsia, high birth weight, season of birth, family history of diabetes (both DM1 and DM2), and HLA antigens. Furthermore, there is some evidence for inter-relationships between individual risk factors as well as gene by environment interactions. We suggest future areas for research based on existing findings.