An Examination of Concomitant Non-Medical Use of Gabapentin and Opioids. - Project Summary/Abstract Gabapentin is widely prescribed in neurology, psychiatry, and primary healthcare for the treatment of epilepsy and neuralgia, as well as off- label during treatment for opioid use disorder (OUD) to mitigate withdrawal symptoms, manage pain, and address patient anxiety. From 2002-2015, prescriptions for gabapentin tripled, and gabapentin-involved opioid overdoses have also increased in recent years. As a result, starting in 2017, multiple states reclassified gabapentin to Schedule V under state-controlled substances laws. In 2019, the Food and Drug Administration required labeling changes for gabapentin that included a warning of potential respiratory depression when used with opioids medications. Limited reports document non-medical use (NMU) of gabapentin, especially among opioid users and individuals receiving medication assisted treatment (MAT) for OUD. Gabapentin is non-medically used to potentiate the euphoric effects of opioids, including MAT medications buprenorphine and methadone, as well as to self-treat OUD symptoms. Aside from these brief reports, systematic studies examining the concomitant NMU of gabapentin and opioids are lacking. At the same time, research documents the therapeutic benefits of administering gabapentin to individuals in treatment for substance use disorder. Studies have shown that individuals receiving daily doses of gabapentin reported decreased symptoms of withdrawal and gabapentin works well in combination with methadone for opioid detoxification. Given the growing reports of NMU of gabapentin, especially NMU co-occurring with opioids and MAT; the accepted use of prescribed gabapentin among treatment clients; and the dearth of systematic data examining the concomitant NMU of gabapentin and opioids, the proposed exploratory R21 study seeks to examine this phenomenon. The study will utilize a social ecology theory-driven design to investigate motivations for concomitant NMU, gender and racial/ethnic differences, and histories of MAT and prescribed gabapentin. The following specific aims will be accomplished: 1) Assess demographic, sociocultural, and psychosocial characteristics across three social ecological domains (intrapersonal, interpersonal, and community) which influence concomitant NMU of gabapentin/opioids; and routes of administration, modes of acquisition, and consequences (n=150); 2) Construct and ethnographic decision model (EDM) of the decision to initiate concomitant NMU of gabapentin/opioids (n=60); and 3) Examine NMU of gabapentin in combination with MAT, including motivations, effects, and consequences (n=30). The sample will be collected among individuals entering treatment for OUD and will include approximately equal numbers of men and women, as well as, and Black, Hispanic, and white individuals. The study will advance Goal 1 of NIDA’s strategic plan by identifying environmental, behavioral, and social causes and consequences of concomitant NMU of gabapentin and opioids and it will be informative for OUD treatment providers and prescribers and aid in the development of prevention and intervention strategies. This exploratory study is innovative in its use of EDM methodology.