Incidence of ischaemic heart disease and stroke among people with psychiatric disorders: retrospective cohort study

Background: Psychiatric disorders are associated with increased risk of ischaemic heart disease (IHD) and stroke, but it is not known whether the associations or the role of sociodemographic factors have changed over time. Aims: To investigate the association between psychiatric disorders and IHD and stroke, by time period and sociodemographic factors. Method: We used Scottish population-based records from 1991 to 2015 to create retrospective cohorts with a hospital record for psychiatric disorders of interest (schizophrenia, bipolar disorder or depression) or no record of hospital admission for mental illness. We estimated incidence and relative risks of IHD and stroke in people with versus without psychiatric disorders by calendar year, age, gender and area-based deprivation level. Results: In all cohorts, incidence of IHD (645 393 events) and stroke (276 073 events) decreased over time, but relative risks decreased for depression only. In 2015, at the mean age at event onset, relative risks were 2- to 2.5-fold higher in people with versus without a psychiatric disorder. Age at incidence of outcome differed by cohort, gender and socioeconomic status. Relative but not absolute risks were generally higher in women than men. Increasing deprivation conveys a greater absolute risk of IHD for people with bipolar disorder or depression. Conclusions: Despite declines in absolute rates of IHD and stroke, relative risks remain high in those with versus without psychiatric disorders. Cardiovascular disease monitoring and prevention approaches may need to be tailored by psychiatric disorder and cardiovascular outcome, and be targeted, for example, by age and deprivation level