Clinical Research Directory

Inclusion Criteria: * Individuals fluent in English will participate. * Must report recreational use of opioids. * Be within 20% of their ideal body weight. * Are not currently experiencing chronic pain (pain on most days during the past 3 months) * Have a systolic blood pressure of \<=140 and diastolic blood pressure of \<= 90, and a heart rate \<= 90 beats per minute. * Participants must also have a normal electrocardiogram (EKG) reading and bloodwork indicating no major health contraindications. Exclusion criteria: * Significant current physical disease or major psychiatric disorder. * No self-reported current interest in drug abuse treatment. * Women who are pregnant or nursing. * Any comorbid illicit substance use disorders or current clinically significant withdrawal for any abused drug excluding nicotine and caffeine. * Any conditions that preclude safety in the MRI scanner, such as: implanted electrical devices (e.g., cardiac pacemaker, neurostimulator); implanted metallic clips or pins (e.g., aneurysm clip); a history of working with metal (unless able to demonstrate participant is MRI safe), and claustrophobia.