Unmarried individuals face significantly higher risks of depressive symptoms compared with their married counterparts across diverse cultural settings, according to a large-scale analysis.
Data from 106,556 adults was examined for cross-sectional analysis and 20,865 for longitudinal follow-up, representing approximately 541 million adults across 7 countries.
Unmarried people had an 86% higher risk of depressive symptoms. By specific marital status, compared to married individuals, the odds ratios were 1.79 for single, 1.99 for divorced/separated, and 1.64 for widowed individuals, according to study results published in Nature Human Behaviour
Nationally representative data from the US, UK, Mexico, Ireland, Korea, China, and Indonesia was analyzed. The proportion of married participants varied by country, ranging from 64.3% in the US to 87.6% in China. Follow-up periods ranged from 4 to 18 years.
The association between marital status and depression varied significantly by region, sex, and education level. Western countries showed stronger associations than Eastern countries. Men demonstrated higher risk than women, and individuals with higher educational attainment showed greater risk compared with those with lower education levels.
Alcohol consumption emerged as a significant mediator of depression risk, accounting for 3.2% to 34.1% of risk in single individuals, 16.5% to 29.3% in divorced/separated individuals, and 5.9% to13.4% in widowed individuals. Smoking also mediated 22.1% to 43.8% of depression risk among single individuals in China and Mexico.
The analysis controlled for multiple variables including age, sex, educational attainment, income, BMI, and medical history of conditions such as diabetes, hypertension, heart disease, stroke, and cancer.
Limitations included reliance on self-reported symptoms rather than clinical diagnoses, potential ecological bias from social and cultural differences between countries, and exclusion of same-sex marriages due to data unavailability.
The authors declared no competing interests.
