People with serious mental illnesses, including schizophrenia, have greater rates of cardiovascular-related mortality than the general population, and that association has become stronger over recent decades, according to a new study published on April 19th, 2022, in PLOS Medicine by Amanda Lambert of the University of Birmingham, UK, and colleagues.
Previous research has found that persons with severe mental illness have a higher incidence and mortality rate from cardiovascular disease, but it was not known whether that association has changed over time. The new study involved a systemic review and meta-analysis of 108 previous studies including over 30 million participants in high-income countries, all aged 16 to 65 years of age at the time of the development of the psychiatric disorder.
The study found that, overall, the cardiovascular-related mortality rate for people with severe mental illness is about twice that of the general population (SMR 1.96, 95% CI: 1.61–2.39, p<0.001 for schizophrenia). People with schizophrenia are at greater risk than those with bipolar disorder, but the disparity exists across all types of severe mental illness and both cerebrovascular and cardiac mortality. For people with schizophrenia, the pooled hazard ratio/rate ratio for coronary heart disease was 1.8 (95% CI: 1.44–2.24, p<0.001) compared to controls and the pooled standardized mortality ratio for cerebrovascular accidents was 1.93 (95% CI: 1.63–2.28, p<0.001). For both schizophrenia and bipolar disorder, the association with cardiovascular-related mortality grew stronger between the 1970s and the 2000s. For instance, the hazard ratio/rate ratio for mortality from coronary heart disease in people with schizophrenia in the 1990s compared with the 1980s was 1.61 (95% CI: 1.14–2.28, p=0.014).
It was not possible to explore all possible confounders, such as smoking and obesity, and there was also considerable heterogeneity between the studies included in the meta-analysis. More research is needed to understand the reasons for the higher morbidity risk and to assess why it may have been worsening in recent decades.
“The increased relative risk of CVD diagnosis in more recent decades may be a result of disparity in smoking prevalence between people with SMI and the general population or increased use of antipsychotics. The changes since the 1990s approximately coincide with the release of newer, second-generation antipsychotics which are known to have worse metabolic effects,” the authors say.
Lambert adds, “Our systematic review and meta-analysis of over 100 studies has confirmed a strong association between severe mental illness and cardiovascular disease which became stronger in the 1990s and 2000s.”
Reference: “Temporal trends in associations between severe mental illness and risk of cardiovascular disease: A systematic review and meta-analysis” by Amanda M Lambert, Helen M Parretti, Emma Pearce, Malcolm J Price, Mark Riley, Ronan Ryan, Natalie Tyldesley-Marshall, Tuba Saygin Avsar, Gemma Matthewman, Alexandra Lee, Khaled Ahmed, Maria Lisa Odland, Christoph U. Correll, Marco Solmi and Tom Marshall, 19 April 2022, PLOS Medicine.
Funding: This report presents independent research funded by the National Institute for Health and Care Research (NIHR). AML and TM are supported by the NIHR Applied Research Collaboration (ARC) West Midlands. HMP (NIHR Academic Clinical Lectureship) was funded by the NIHR during some of this research. MJP was supported by the NIHR Birmingham Biomedical Research Centre at the University Hospitals Birmingham NHS Foundation Trust and the University of Birmingham. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.