PESTICIDE EXPOSURE AND NEUROPSYCHIATRIC DRUG USE ACROSS DEMOGRAPHIC STRATA IN BRAZIL

Chronic pesticide exposure has been linked to neurotoxicity, yet population-level evidence connecting such exposure to neuropsychiatric medication use remains limited. We evaluated associations between pesticide exposure and per-capita use of centrally acting medicines and assessed their stability across demographic and socioeconomic contexts. We conducted a nationwide ecological analysis using Brazilian municipality-year data (2014–2021), integrating pharmaceutical sales records, population counts, and municipal indicators of human development (HDI), rurality, population aging, racial composition, and income inequality. Per-capita drug use was expressed as milligrams per resident and compared across terciles of pesticide exposure. We estimated incidence rate ratios (IRR) with log-linear models adjusted for calendar year. We visualized results from non-stratified models showing the direction and magnitude of associations across drug classes and municipal characteristics. To test robustness, we stratified municipalities into high/low groups (median split) for HDI, rurality, proportion of elders, racial composition, recalculating pesticide terciles per stratum. Higher pesticide exposure was consistently associated with greater per-capita use of antidepressants and anxiolytics, whereas associations for antiepileptics and antipsychotics were weaker and more heterogeneous. In higher-rurality municipalities, associations included topiramate IRR 2.85(2.72–2.99) and bupropion 4.61(4.40–4.84). In lower-HDI municipalities, zolpidem IRR was 1.99(1.86–2.12), bupropion 2.47(2.33–2.63), and desvenlafaxine 2.16(2.01–2.34). The forest plot map in the image represents the comparative results for rurality. Overall, contextual stratified analyses preserved effect direction, with stronger associations in lower-HDI and higher-rurality settings. These findings support a potential link between pesticide exposure and population-level central nervous system morbidity, underscoring relevance for neurotoxicology and public health.