The relationship between cardiovascular health and common mental disorders among adults aged ≤ 50 years: a systematic review of observational studies

BACKGROUND: Depression and anxiety are common among younger adults and contribute to adverse physical and social outcomes. Evidence suggests a potential bidirectional relationship between common mental disorders (CMDs) and cardiovascular health (CVH). However, this has not been directly established. This review examined the relationship between CVH and CMDs in individuals aged 15-50 years. METHODS: MEDLINE (PubMed), APA PsycINFO, Web of Science, and CINAHL (EBSCO) were searched from inception to 4 November 2024. Observational studies reporting depressive or anxiety symptoms and CVH defined by Life's Simple 7, Life's Essential 8, or adapted composite indices were eligible. Study quality was appraised using the Newcastle-Ottawa Scale and a narrative synthesis was conducted. FINDINGS: Of 25 full-text articles assessed, 11 studies (n = 731,650; mean age 22-48 years) met the inclusion criteria. Nine were conducted in the United States, one in China, and one in Puerto Rico. Seven cross-sectional studies reported an inverse association between CVH and CMDs, with higher CVH associated with lower odds or prevalence of depressive and anxiety symptoms. Four studies, including one cohort, found that CMDs were associated with lower CVH, reflected by higher odds of suboptimal CVH, lower prevalence of ideal CVH, and reduced CVH scores. CONCLUSIONS: Findings suggest a potential bidirectional relationship between CVH and CMDs among adults, though this is inferred from separate analyses rather than directly established using the same studies. Integrated strategies promoting physical activity, a healthy diet, and stress management, alongside primary care initiatives incorporating behavioural support and screening for cardiovascular and mental health risks, may benefit both conditions. Interpretation is limited by the predominance of cross-sectional studies and heterogeneity in study designs, with most studies conducted in high-income settings. Future research should prioritise longitudinal designs and apply diverse analytical methods to better clarify directionality. REGISTRATION: PROSPERO (CRD42024621494).