Research, Urban Planning, Environment and Health

Long-Term Exposure to Air Pollution May Increase the Odds of Depression

A study carried out in Barcelona reveals an association between long-term exposure to traffic-related pollutants and a history of depression


A greater probability of developing depression following long-term exposure may be added to the long list of negative health effects already attributed to air pollution. This is the conclusion of a study published in the International Journal of Hygiene and Environmental Health led by a team from the Barcelona Institute for Global Health (ISGlobal), a research centre supported by the ”la Caixa” Banking Foundation.

The team’s main objective was to investigate the possibility of associations between long-term exposure to air pollution and a history of depression or anxiety disorders. They compared data on levels of exposure to various ambient air pollutants in Barcelona with information collected in the course of interviews with nearly 1000 people resident in the city aged between 45 and 74 years. The study group were volunteers belonging to the ALFA (Alzheimer and Families) cohort who participated in several studies related to Alzheimer disease undertaken by the Pasqual Maragall foundation.

The results show a significant association between long-term exposure to air pollution (NOx, NO2, PM2.5 and PM10), a history of depression and the use of antidepressants. The association between increased pollution and a history of anxiety disorders was not statistically significant, but the analysis did show that people exposed to higher concentrations of air pollutants were more likely to have used anxiolytics, specifically benzodiazepines.

“While there is still no consensus in the literature on the relationship between exposure to air pollution and depression, our results are consistent with those of other researchers, who have found similar associations” explains Cristina Vert, an ISGlobal researcher and the first author of the study.

According to the ISGlobal researcher Mireia Gascon, co-author of the study, “The findings of this study are yet another indication of the possible negative impact of air pollution on the mental health of the population.” However, she goes on to make the point that “further studies on larger and more representative study populations using a longitudinal design will be necessary to confirm our conclusions.”


Vert C, Sánchez-Benavides G, Martínez D, et al., Effect of long-term exposure to air pollution on anxiety anddepression in adults: A cross-sectional study. Int J Hyg Environ Health. 2017 Aug;220(6):1074-1080. doi: 10.1016/j.ijheh.2017.06.009. Epub 2017 Jul 3.