Depression outcomes correlated to exposure to per- and poly-fluoroalkyl substances (PFAS)

Per- and poly-fluoroalkyl substances (PFAS) are fluorinated organic compounds known as forever chemicals that are used in many materials, from cooking appliances to industrial detergents. Given their high chemical stability due to their lipophilic properties and widespread use, PFAS tend to bioaccumulate in the cardiac, hepatic, renal, gastrointestinal, and neural tissues, resulting in a variety of malignant and non-malignant diseases. Depression is a prevalent mental health condition that affects an individual's activities of daily living. Depression is associated with numerous other chronic diseases, as well as the exacerbation of those conditions. With the increasing exposure to PFAS, this study set out to further examine the toxic correlation of nine subtypes of PFAS with depression outcomes in the U.S. adult population. PFAS exposure was analyzed from serum laboratory samples from the National Health and Nutrition Examination Survey (NHANES) datasets from 2015 to 2018 and was analyzed via multiple linear regression and multiple logit regression approaches. Depression ratings were based on individual responses to the Patient Health Questionnaire (PHQ9) and then characterized as none (score of 0-4), mild (score of 5-9), moderate (score of 10-14), moderately severe (score of 15-19), and severe (score of 20-27). All statistical analyses are conducted with R software version 4.4.0. The observed correlation was significant for a subset of PFAS subtypes. The findings suggest a medium concentration exposure to branch perfluorooctanoic acid isomers (BFOA) (odds ratio (OR) 2.010; [95% confidence interval (CI), 1.013, 3.988]), a medium concentration exposure to n-perfluorooctanoic acid (NFOA) (OR 6.073; [95% CI, 1.069, 34.498]), and medium concentration exposure to perfluorononanoic acid (PFNA) (OR 3.992; [95% CI, 1.261, 12.632]) were positively correlated with depression occurrence in adults aged 20 years and older who were not incarcerated. Analyzed covariates that were most common among depressed individuals included being female; widowed, divorced, separated, or never married; having a BMI of obese; and a current smoker. Given the documented negative health effects and current research gaps, researchers should continue to analyze the effects of PFAS exposure while healthcare and governmental institutions disseminate education, encourage laboratory testing, and fund elimination efforts of PFAS exposure. More investigation is required to support or reject these findings.