been shown to alter thyroid-stimulating hormone and thyrotropin-releasing hormone consistenly49. However, conflicting results were obtained by studies investigating thyroid function in long-term opioid users and controls49. Although the exact pathway by which the combination of CoD, ND, and OD interacts with rs8052287 in the context of SI is unclear, our “thyroid” hypothesis provides a potential pathogenetic mechanism linking polysubstance dependence, genetic liability to hypothyroidism, and SI. Further studies are needed to test this hypothesis, which has some obvious potential therapeutic implications.
