Stress and Opioid Misuse Risk: The Role of Endogenous Opioid and Endocannabinoid Mechanisms

Inclusion Criteria: * Intact cognitive status and ability to provide informed consent * Ability to read and write in English sufficiently to understand and complete study questionnaires (which are only validated in English) * Age 18 or older And * Presence of persistent daily low back pain of at least three months duration and of at least a 3/10 in average intensity Exclusion Criteria: * History of renal or hepatic dysfunction * Reports of current or past alcohol or substance abuse or treatment for such condition * A reported history of PTSD, psychotic, or bipolar disorders * Chronic pain due to malignancy (e.g., cancer) or autoimmune disorders (e.g., rheumatoid arthritis, lupus) * Reports of recent benzodiazepine use (confirmed via rapid urine screening prior to each lab session) * Any medical conditions (e.g., significant cardiovascular disease) that the study physician feels would contraindicate participation in the lab stressors * Reported daily opiate use within the past 6 months, or use of any opioid analgesic medications within 3 days of study participation (confirmed through rapid urine screening prior to each lab session) * Pregnancy (females only, to avoid fetal drug exposure - pregnancy tests conducted prior to each lab session to confirm eligibility) * Prior allergic reaction/intolerance to oxycodone or its analogs