People with severe mental illness have cardiovascular-related mortality rates that are nearly twice as high as the general population, according to a new meta-analysis published in PLOS Medicine. Led by Amanda Lambert of the University of Birmingham, the authors conducted a systematic review of 108 existing studies, representing over 30 million participants in high-income countries. 

Although the disparity held across all types of severe mental illness, the review showed that people with schizophrenia generally had higher incidence of cardiovascular disease (CVD) and higher mortality rates than those with bipolar disorder. 

The data also unearthed interesting temporal trends. For people with schizophrenia or bipolar disorder, for example, associations between mental illness and cardiovascular mortality grew stronger between the 1970s and the 2000s. While the exact causes for higher mortality toward the end of that period was unclear, the timeline suggests several possible links which may warrant further exploration. 

“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 study’s authors said in a statement.