According to a new study, researchers examine that African Americans and Latinos are significantly more likely to experience serious depression than Whites, but chronic stress does not seem to explain these differences. They also found that African Americans and Latinos were more likely to have higher levels of chronic stress and more unhealthy behaviors. The study was published in  Preventive Medicine.

To examine the relationship between unhealthy behaviors, chronic stress, and risk of depression by race and ethnicity, researchers used data collected on 12,272 participants, aged 40 to 70 years, from 2005 to 2012. These data were part of the National Health and Nutrition Examination Survey (NHANES), a nationally representative health interview and examination survey of U.S. adults. This age range population was selected for this study to capture the effects of chronic stress over the lifetime of the participants.

Understanding the social and behavioral complexities associated with depression and unhealthy behaviors by race/ethnicity can help us understand the overall health to improve. The unhealthy behaviors examined were current cigarette smoking, excessive or binge drinking, insufficient exercise, and fair. The researchers measured chronic stress using ten objective biological measures, including blood pressure, body mass index, and total cholesterol.

Chronic stress during adulthood may be an important factor in depression. This effect may be worse among racial and ethnic minorities due to the stress experienced from social and economic inequalities, but the relationships between race/ethnicity, stress, behavior, and depression are not well understood. A theoretical framework called the Environmental Affordances model has been proposed to explain how chronic stress and risk behaviors interact to affect health.

On average, Latinos and African Americans had more chronic stress, more unhealthy behaviors, and more chance for depression. However, the study found that engaging in more unhealthy behaviors was strongly associated with a greater chance for depression only in African Americans and Whites.

The study also found that for all three groups:

1. The level of chronic stress did not affect the relationship between unhealthy behavior and a chance for depression

2. Unhealthy behaviors did not alter the association between stress and depression opportunity

3. More education offered more protection against depression

In the previous study, this study found that in all three racial/ethnic groups, chronic stress levels were inversely related to excessive or binge drinking. This study also found no evidence as some previous research has suggested that African Americans engage in unhealthy behaviors as a way to cope with chronic stress and reduce depression interact with chronic stress in Latinos to increase depression.

The scientists point to differences in their research design and their use of physiological measures of chronic stress instead of self-reported measures as possibly contributing to their different findings. They note that their results highlight the complex relationships between chronic stress, unhealthy behaviors, and mental health among different racial and ethnic groups.