Unmarried people may have a higher risk for depression

Key takeaways:

• Not being married corresponded with an increased risk for depressive symptoms.
• Depression risk was higher in Western countries vs. Eastern countries and in men vs. women.

People who are not married may be over 80% more likely to have depressive symptoms compared with their married peers, according to a multinational analysis published in Nature Human Behavior.

Study results also showed higher risk for several subgroups, such as men and divorced or separated people, the researchers noted.

Marriage has been shown to have protective effects against mental illnesses like dementia and mild cognitive impairment, but most of the past studies examining ties between mental health and marriage have used data from only single and typically Western countries, Xiaobing Zhai, from Macao Polytechnic University in Macau, and colleagues wrote.

“Variations in culture, socioeconomic development and education can uniquely shape marital behaviors across countries,” they explained.

The researchers conducted a multistage analysis that started with examining the data of 106,556 participants from studies across seven countries — including the United States, Ireland, United Kingdom, South Korea, Mexico, Indonesia and China — to determine depression risk among unmarried people. over a follow-up period of 4 to 18 years in a subset of 20,865 people.

Overall, unmarried people had a greater risk for depressive symptoms vs. married people across all countries (pooled OR = 1.86; 95% CI, 1.61-2.14).

The researchers then performed a prospective longitudinal study on a subset of 20,865 participants to examine the underlying causal mechanisms between marital

status and later risk for depressive symptoms. They found that the risk for depression increased by:

• 79% (pooled OR = 1.79; 95% CI, 1.46-2.2) among single people;
• 99% (pooled OR = 1.99; 95% CI, 1.53-2.53) among divorced or separated people; and
• 64% (pooled OR = 1.64; 95% CI, 1.28-2.11) among widowed people.

The risk for depression appeared greater in Western countries vs. Eastern countries (beta = 0.36; 95% CI, 0.16-0.56), in men vs. women (beta = 0.25; 95% CI, 0.003-0.47) and in those with higher educational attainment vs. lower educational attainment (beta₂ = 0.34; 95% CI, 0.11-0.56).

Zhai and colleagues added that alcohol significantly mediated the increased risk for depressive symptoms among unmarried people in China, Korea and Mexico, while smoking served as a mediator among single people in China and Mexico.

Researchers noted that depressive symptoms were self-reported through questionnaires rather than being clinically diagnosed, making it difficult to distinguish between first-time and recurrent depressive symptoms and treated vs. untreated depression.

Zhai and colleagues suggested that the health benefits from marriage may be due to factors like the exchange of social support, greater access to economic resources “and the positive influence of spouses on each other’s mental well-being.”

They concluded that the data “underscore the importance of considering cultural, socioeconomic and behavioral contexts in future research to better understand and address the mental health disparities associated with marital status.”