Schizophrenia Spectrum Disorders and Risk for Cancer Morbidity and Mortality

Abstract

This chapter reviews recent epidemiological studies on the relationship between schizophrenia spectrum disorders and cancer morbidity and mortality. Three sorts of findings are discussed: (1) reduced risk for cancer morbidity and mortality among patients diagnosed with schizophrenia and their first-degree relatives; (2) enhanced risk for cancer morbidity among patients with bipolar spectrum disorders, and (3) no increased risk for cancer morbidity among patients suffering from schizoaffective disorders. The genetic hypothesis suggests that the presence of genes with the dual effect of reducing the cancer risk and disrupting neurodevelopment is a plausible explanation for this association in schizophrenia patients. The environmental contributors to malignancy include health behavior, psychotropic medications, and metabolic syndrome, are suggested to explain the increased cancer risk among bipolar patients. The identification of risk and protective genes that mediate the development of malignant processes in some major psychiatric disorders is a new challenge in the field of psycho-oncology.