Understanding and characterizing the higher rates of medical comorbidities in serious mental illness

Individuals with serious mental illness (SMI) contend with medical comorbidities like hypertension, lowering their life expectancies. Here we evaluated these comorbidities in the Genomic Psychiatry Cohort, a large, diverse sample of subjects with SMI and controls. We also assessed the relationship of these illnesses with factors such as ancestry. Participants were sorted into one of three groups: 1) schizophrenia and schizoaffective disorder-depressed type (SZ, n = 8188), 2) bipolar with and without psychosis and schizoaffective disorder-bipolar type (BD, n = 5577) and 3) controls (CON, n = 10,850). Logistic regression models provided the odds of subjects endorsing heart problems, hypertension, high blood sugar, high cholesterol, and cancer compared to CONs. Similar models were used to evaluate the effects of probable alcohol use disorder (pAUD), probable tobacco use disorder (pTUD), ancestry, and sex. Both SZ and BD had higher odds of all five comorbidities compared to CONs, with OR ranging between 1.61 and 2.38 for SZ and 2.08 to 3.14 for BD (p < 0.0033). Having both SMI and pAUD was associated with higher odds of heart problems, hypertension, and cancer, though for pTUD this association held true for heart problems and cancer in SZ only (p < 0.0033). When comparing African-ancestry (AA) and European-ancestry (EA), hypertension and high blood sugar impacted AA with SMI more, though high cholesterol and cancer impacted EA with SMI more. Our findings suggest that SZ and BD are associated with higher rates of medical comorbidities, and factors such as pAUD, pTUD, and ancestry may be implicated.