Lancet Psychiatry. 2025 Oct;12(10):768-779. doi: 10.1016/S2215-0366(25)00262-7.
ABSTRACT
BACKGROUND: People with severe mental illness have a 10-20 year reduced life-expectancy compared with the general population. Respiratory diseases are a main cause of this premature mortality, but no comprehensive meta-analysis of overall and respiratory cause-specific mortality risk in this population exists. We aimed to evaluate the mortality from specific respiratory diseases for people with pooled severe mental illnesses and specific diagnoses, alongside mortality for specific mental disorders.
METHODS: For this large-scale random-effects meta-analysis, we searched PubMed, PsycINFO, Embase, Scopus, African Index Medicus, and LILACS from database inception to April 6, 2025, for prospective or retrospective cohort studies published in English. We included studies reporting on patients with schizophrenia spectrum disorder, bipolar disorder, major depressive disorder or depressive episodes, or mixed severe mental illness (defined as at least two among bipolar, depressive, and schizophrenia spectrum disorders). Publications had to include a control group from the general population and quantified reporting. We excluded cross-sectional studies, reviews, systematic reviews, and meta-analyses; studies that did not have respiratory-related mortality data; studies of clustered mixed groups that did not have at least 70% of the patient sample corresponding to our diagnoses, or studies in which the data were not suitable for meta-analysis. The primary outcome was adjusted risk ratio (RR) of overall respiratory disease-related mortality in people with severe mental illness (both pooled and for the specific severe mental disorders) versus the general population control group. Two authors extracted the data using a predetermined data extraction form. The information extracted included first author, country, setting (inpatient, outpatient, or both), data source, design of the study (prospective or retrospective), number of participants and their demographics (sex and mean age), specific severe mental illness and respiratory disease diagnosis, and the RR mortality of each respiratory disease. We assessed the risk of bias in each study using the Newcastle-Ottawa scale and heterogeneity was assessed with a multilevel random-effects meta regression. Individuals with lived experience of mental illness were not involved in the design, analysis, or dissemination of this study. The study was conducted in accordance with PRISMA and was registered with PROSPERO (CRD42024563552).
FINDINGS: Our search identified 83 studies that met the eligibility criteria. We included 4 837 720 people with pooled severe mental illness (2 383 821 males [49·3%] and 2 453 899 females [50·7%]; mean age 57·7 years [SD 13·5]). Data on ethnicity or race were insufficiently reported to be included in our study. Our control group comprised 785 538 236 individuals from the general population (382 185 432 [48·7%] males and 403 352 804 [51·3%] females). 57 studies included people with schizophrenia spectrum disorder (2 979 972); 21 included people with bipolar disorder (491 758); 20 included people with major depressive disorder (1 327 642); and ten studies included individuals with mixed severe mental illness (968 326). Across all 83 studies, pooled severe mental illness was associated with significantly higher respiratory-related mortality compared to the general population (RR 2·28 [95% CI 2·02-2·56]). People with schizophrenia spectrum disorder had the highest respiratory-related mortality compared to the general population (RR 2·60 [2·28-2·96]; from 57 studies), followed by bipolar disorder (RR 1·96 [1·57-2·43]; from 21 studies), mixed severe mental illness (RR 1·91 [1·43-2·54]; from ten studies), and major depressive disorder (RR 1·72 [1·39-2·13]; from 20 studies). In the quality assessment, the mean score was 8·7 out of 9 points. 78 included studies (94%) were ranked as good quality (a score of 7-9 on the Newcastle-Ottawa scale) and five studies (6%) were ranked as fair quality (a score of 5-6).
INTERPRETATION: Overall and specific respiratory disease mortality risk is significantly higher in individuals with pooled severe mental illnesses and specific severe mental illnesses than in the general population. Programmes for smoking cessation, lung cancer screening, vaccination against respiratory infections, and pulmonary health monitoring in people with severe mental illness should be developed and implemented to address the unmet health needs of this population.
FUNDING: Instituto de Salud Carlos III, EU.
PMID:40967730 | DOI:10.1016/S2215-0366(25)00262-7
