The largest meta-analysis to date found that risk of dying from cardiovascular disease (CVD, including conditions such as coronary heart disease, cerebrovascular disease and congestive heart failure) is 85% higher in people with severe mental illness (SMI; Correll et al., 2017). According to that study, factors which increased risk for cardiovascular disease in SMI patients included antipsychotic use and higher body mass index (BMI).
However, the interplay between SMI and CVD and their risk factors is complex. Reverse causation or confounding might compromise our ability to draw causal conclusions and in fact, no study to date has addressed the causal effects between SMI and CVD or the potentially mediating role of factors such as BMI.
The observed association between SMI and CVD also points towards shared biological correlates. Epigenetic processes such as DNA methylation, can present a potential biological mechanism linking SMI and CVD. DNA methylation signatures have been robustly linked to SMI and SMI / CVD risk factors (Barker, Walton, & Cecil, n.d.; Dick et al., 2014; Joubert et al., 2016; Kato et al., 2015), but no study to date has investigated the epigenetic overlap between CVD and SMI.