The relationship between severe mental illness and physical multi-morbidity: a meta-analysis and call for action

Question: People with mental illness have a higher prevalence of several chronic physical health conditions and the prevalence of physical multi-morbidity is expected to rise. The aim of this study was to assess the strength of the association between severe mental illness (SMI) and physical multi-morbidity.

Study selection and analysis We systematically searched PubMed/ Medline, Scopus, Embase, Web of Science, PSYCInfo, and the behavioural sciences collection databases, from inception to the 31st of January 2023, for studies that investigated the association between SMI and physical multi-morbidity. Humans of any age either clinically diagnosed and/or currently receiving treatment for a SMI, specified as schizophrenia (and related psychotic disorders), bipolar disorder, and psychotic depression were eligible. Data from studies selected for inclusion were converted into odds ratios (ORs), with a subsequent meta-analysis conducted.

Findings We included 19 studies with a total of 194,123 patients with SMI with different diagnoses and drawn from the general population. The pooled OR for physical multi-morbidity in people with versus without SMI was 1.84 (95% CI 1.33-2.54), with the analysis indicating a high level of heterogeneity (98.38%). The other 15 studies included in the systematic review, for which it was not possible to conduct a meta-analysis, showed strong associations between SMI and physical multi-morbidity.

Conclusions The current evidence highlighted the link between SMI and physical multi-morbidity. A multidisciplinary approach, is now urgent, to develop the best models of services tailored to patients with SMI with physical multi-morbidities to improve physical, mental, and social outcomes