New systemic literature review concludes that policies such as parental leave can reduce individuals' risk of depression, while policies that cut social welfare or lead to insecurity increase depression risk. Credit: Damir Samatkulov, Unsplash, CC0 (https://creativecommons.org/publicdomain/zero/1.0/)

Policies that impact social determinants of health may influence an individual's risk of depression, according to a new study published in PLOS One by Mary Nicolaou of the Amsterdam UMC, The Netherlands, and colleagues.

Globally, depression is one of the leading causes of burden of disease worldwide. Interventions focused on individual behaviors, while effective, reduce depression incidence by only about 20%, meaning that most risk factors are left unaddressed. In the new study, researchers took a new look at existing data on the social and economic drivers of depression in high-income countries. The authors analyzed 135 studies that tracked depression rates, mental health symptoms, and antidepressant use in relation to policy changes.

The study found consistent evidence that policies improving paid parental leave, employment access, housing stability, and income support are linked to lower rates of depression and psychological distress. On the flip side, cuts to social welfare such as unemployment benefits, and financial insecurity were associated with worsening mental health, particularly among single parents and low-income households. In the U.S., expanding Medicaid or health coverage led to measurable drops in mental distress, especially after job loss.

While few of the included studies tested underlying causal mechanisms, and only data through 2022 was available, the authors conclude that positive intervention on social determinants of health may be a powerful tool for preventing depression at the population level.

The authors add, "Instinctively we know that the wider set of conditions and systems in which people are born, live, work and age can influence their mental health. However, when it comes down to it, we often target the individual, assuming that they are able to overcome structural barriers such as poverty.

"This study provides consistent, high-quality evidence that policies that promote paid employment can improve mental health. Conversely, we find that reduced entitlements to social welfare, loss of income, poverty, instability of housing and financial crises are likely to reduce population-level mental health.

Overall, a spectrum of actions is needed to address mental health, demanding comprehensive approaches across policy domains.

More information: Mary Nicolaou et al, Preventing depression in high-income countries—A systematic review of studies evaluating change in social determinants, PLOS One (2025). DOI: 10.1371/journal.pone.0323378  Journal information: PLoS ONE