Developmental Exposure to Endocrine Disruptors and Persistent Pollutants Heightens Addiction Risk via Toxicological Mechanisms.

Endocrine-disrupting chemicals (EDCs) and persistent organic pollutants (POPs) cross the placenta and accumulate during gestation and early postnatal life, periods of heightened hormonal and neurodevelopmental plasticity. Exposure to contaminants such as bisphenol A (BPA), phthalates, polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) during these critical windows can reprogram endocrine and neural circuits, resulting in persistent behavioral alterations. This review synthesizes mechanistic evidence from animal models and epidemiological studies linking developmental EDC/POP exposure to attention deficits, impulsivity, anxiety and altered reward sensitivity-phenotypes defined here as addiction vulnerability (addiction-relevant endophenotypes) rather than clinically diagnosed substance-use disorder (SUD). We propose a two-hit, adverse outcome pathway (AOP)-informed model in which prenatal EDC/POP exposure induces endocrine-related perturbations that prime reward and stress circuitry. Subsequent exposure to psychoactive drugs and/or chronic stress then acts on these sensitized systems to increase the probability of maladaptive reinforcement learning and impaired behavioral control. Mechanistically, early-life exposures disrupt thyroid and sex-steroid signaling, dysregulate the hypothalamic-pituitary-adrenal axis, and alter dopaminergic, serotonergic, and glutamatergic neurotransmission with additional modulation by epigenetic reprogramming, oxidative stress, and neuroinflammation. Human cohort studies consistently associate prenatal BPA and phthalate exposures with adverse neurobehavioral and externalizing symptoms in children, supporting this framework while underscoring the limited availability of longitudinal data linking early exposure to SUD outcomes. Integrating these findings within an AOP perspective highlights the importance of developmental timing, sex, dose, genetic background, and co-exposures, and supports risk-assessment strategies that account for sequential environmental and drug exposures.