Serious mental illness linked to multiple physical illnesses

The results of a new meta-analysis showed that serious mental illness (SMI), including bipolar disorder or schizophrenia spectrum disorders, is associated with a twofold risk of comorbid physical illness.

“Although the treatment of physical and mental health remains isolated in many health services globally, the high prevalence of physical multimorbidity demonstrates the urgent need for integrated care models that address physical and mental health outcomes of people with serious mental illness,” the authors. led by Sean Halstead, MD, of the University of Queensland School of Medicine in Brisbane, Australia, wrote.

The findings were published online on April 17 a The Lancet Psychiatry.

Shorter shelf life?

SMI is associated with reduced life expectancy, and experts speculate that other chronic illnesses, either physical or psychiatric, may underlie this association.

Although previous research has paired SMI with comorbid physical illnesses, the researchers noted that this study is the first to focus on both physical and psychiatric multimorbidity in people with SMI.

Researchers conducted a meta-analysis of 82 observational studies including 1.6 million individuals with SMI and 13.2 million control subjects to determine the risk of physical or psychiatric multimorbidity.

Studies were included if participants were diagnosed with a schizophrenia spectrum disorder or bipolar disorder, and the study assessed physical multimorbidity (at least two physical health conditions) or psychiatric multimorbidity (at least three psychiatric conditions), including baseline SMI.

The researchers found that people with SMI had more than twice the risk of physical multimorbidity than those without SMI (odds ratio [OR], 2.40; 95% CI, 1.57-3.65; p = 0.0009).

Physical multimorbidity, which included cardiovascular, endocrine, neurological, gastrointestinal, musculoskeletal, and infectious disorders, was prevalent at similar rates in both schizophrenia spectrum disorder and bipolar disorder.

The ratio of physical multimorbidity was approximately four times greater in younger SMI populations (mean age 40; OR, 3.99; 95% CI, 1.43–11.10) than in older populations ( mean age > 40; OR, 95% CI, 0.96-2.51 subgroup differences, p = 0.0013).

In terms of absolute prevalence, 25% of TMS patients had physical multimorbidity and 14% had psychiatric multimorbidity, which were mainly anxiety and substance use disorders.

The researchers speculated that the physical multimorbidity in SMI could result from the side effects of psychotropic medications, which are known to cause rapid cardiometabolic changes, including weight gain. In addition, lifestyle factors or non-modifiable risk factors could also contribute to physical multimorbidity.

Limitations of the study included its small sample sizes for subgroup analyses, and insufficient analysis for significant covariates, including smoking rates and symptom severity.

“While health services and treatment guidelines often operate under the assumption that people have a single primary diagnosis, these results attest to the clinical complexity that many people with serious mental illness face in relation to the burden of chronic disease,” the researchers wrote. They added that a greater understanding of the epidemiological manifestations of multimorbidity in SMI is “imperative”.

There was no funding source for this study. Halstead is supported by the Australian Research Training Program grant. Other disclosures were noted in the original article.