6. Conclusions
Endogenous concentrations of opioid peptides and receptors are under tonic control of circulating androgens. Androgen-induced modulations of these peptides and receptors lead to functional consequences on opioid-mediated behavior. Some of these consequences have clinical relevance, particularly in regard to pain sensitivity, sensitivity to opioid analgesia, and sensitivity to opioid-mediated reward and reinforcement. A greater understanding of how androgens influence these outcomes would lead to better clinical management of both chronic pain and substance use disorders. This review identifies several topics that remain understudied in this area and proposes several lines of research that may carry meaningful translational and public health impact.