A Mendelian randomization approach using genetic variants as statistical “instruments” found that confiding in others about depression risk, watching television, and daytime napping are key social and lifestyle factors closely tied with increased odds of depression, according to a study in the American Journal of Psychiatry.

The study was an examination of baseline data from the UK Biobank which included adults of white British ancestry. A total of 106 modifiable risk factors for depression were identified from the data, including variables related to lifestyle (exercise, sleep, media consumption, diet), social (support and engagement), and environmental (green space and pollution) factors. There were 118,378 participants in the full sample.

Researchers defined incident depression as minimal depressive symptoms at baseline and clinically significant depression during the time of the follow up. Reported traumatic life events and polygenic risk scores produced from large-scale genome-wide association studies for major depression were used to identify individuals who were at risk for incident depression.

To identify variables associated with incident depression, the investigators conducted an exposure-wide association scan of the data. Modifiable factors associated with depression that were identified in patients at-risk of depression – including confiding in others, sleep duration, computer use, physical activity, and television watching – were tested in follow-up Mendelian randomization analyses.


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These analyses found that the factors most associated with depression included confiding in others about depression risk (odds ratio [OR], 0.76; 95% CI, 0.67-0.86; P =2.53×10-5), television use (OR, 1.09; 95% CI, 1.05-1.13; P =6.81×10-6), and daytime napping (OR, 1.34; 95% CI, 1.17-1.53; P =1.82×10-5).

A limitation of this study was the UK Biobank’s lack of data pertaining to modifiable psychological risk factors of depression, such as coping styles.

The researchers concluded that the findings “prioritize an array of potential targets for prevention — most robustly, social support factors, media use, and circadian habits — with the potential to reduce the risk of depression even in” individuals with genetic or environmental risk factors for depression.

Disclosure: Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.

Reference

Choi KW, Stein MB, Nishimi KM, et al. An exposure-wide and Mendelian randomization approach to identifying modifiable factors for the prevention of depression. Am J Psychiatry. 2020;177(10):944-954. doi: 10.1176/appi.ajp.2020.19111158