The failing cascade: Comorbid post traumatic stress- and opioid use disorders

Opioid use disorder (OUD) is a mounting public health problem with substantial morbidity and mortality. Stress involvement in the course of OUD is generally accepted, but little is understood about the underlying neurobiological mechanisms in part due to a lack of laboratory-based models for chronic stress exposure. Post-traumatic stress disorder (PTSD) may be construed as a psychopathological prototype of chronic stress owing to the essential diagnostic criteria of experiencing and reliving a stressful event(s). Literature search on OUD and PTSD neurobiology was undertaken and the relevant data were integrated within four key areas: (1) OUD and PTSD comorbidity; (2) neurobiological overlap between OUD and PTSD; (3) chronic opioids- and stress-induced alterations of the reward-, stress- (i.e., "anti-reward") and related circuits and (4) mechanistically informed treatments of OUD and/or PTSD. Our findings suggest that even in the absence of prior opioid exposure PTSD patients may be susceptible for the development of OUD by the reason of similar (to those induced by opioids) reward alterations that may be targeted for therapeutic interventions.