Cannabidiol, Morphine, Pain

Eligible participants will be asked to participate in a total of three experimental sessions with each session day separated by at least one week. Each session day will last approximately 6-7 hours. In the morning of each of the three study sessions, participants will be asked to complete baseline assessments which include self-report questionnaires (answering questions about how they feel), vital sign measurements (blood pressure, heart rate, oxygen saturation, temperature, and pupillometry) will be taken using a non-invasive (external) vitals monitor, and lastly thermal (heat and cold) and mechanical sensitivity testing will be done. Participants will be asked to take an oral morphine capsule. Participants will participate in 2 smoking sessions where they will be asked to smoke cigarettes or a vaporizer balloon containing either cannabidiol or a placebo (a blank). Participants will be asked to complete the same battery assessments mentioned above, which include self-report questionnaires (answering questions about how they feel); vital sign measurements (blood pressure, heart rate, oxygen saturation, temperature, and pupillometry) will be taken using a non-invasive (external) vitals monitor; and lastly thermal (heat and cold) and mechanical stimulation will be administered to test pain sensitivity. Participants will be asked to complete subjective questionnaires and have vital signs (blood pressure, heart rate, oxygen saturation, temperature, and pupillometry) measured multiple times throughout the visit; these measurements will be monitored for reasons such as safety. After completing the second round of smoking and battery assessments, participants will be provided with lunch and can relax, watch television, listen to music, or read. Once vital signs and questionnaire ratings have returned to baseline levels; participants can leave the laboratory.