Background and objectives: Psychological distress is one of the greatest health threats facing humanity and has been hypothesized to represent an evolutionary mismatch. This hypothesis can be tested in semi-traditional societies that are undergoing transitions to modern lifestyles. This study used an evolutionary medicine framework to examine the predictors of psychological distress symptomology in a semi-modern ethnic minority village in rural Vietnam that is transitioning into a developing economy.

Methodology: A cross-sectional survey was conducted in Chieng Sai Village among White Thai ethnic minority adults aged 18-75. The DASS-21 scale was used to measure the prevalence of psychological distress symptoms, and a closed format questionnaire was used to collect data on independent variables. Binary logistic regression analyses were used to determine associated factors of psychological distress symptomology.

Results: The prevalence of psychological distress symptoms was 33.2% (depression=16.9%, stress=16.3%). Common features of modernity, such as low levels of exercise, boredom, and low income, showed a positive association with psychological distress, while lifestyle features that were more similar to those expected in the evolutionary past and that fulfilled evolutionary adaptations, such as getting enough sleep, physical exertion, and earning sufficient income (access to resources), showed a negative association with psychological distress.

Conclusions and Implications: This study suggests that modern lifestyles might have generated evolutionary mismatches that have negative impacts on mental health in Chieng Sai Village. Future research should focus on determining the causal relationship between psychological distress and evolutionary mismatches. Evolutionary medicine approaches to understanding and treating psychological distress are potential forces of disease reduction to be considered in public health and educational policy.