This study will examine sex differences in the effects of cannabis in people that regularly use it. Men and women that use cannabis at least 4 days a week will participate in a study involving 1-3 in-person visits. The first visit will be used to determine eligibility for the study and will include a blood draw for genetic testing. Most participants will only complete the first visit. Participants that are eligible for the second part of the study will complete two additional visits. These two visits will last 7 hours each and take place at least two days apart. Visits include administration of either THC, the chemical responsible for many of the psychoactive effects of cannabis, or a placebo; completion of questionnaires; repeated blood draws; and a 1-hour brain scan.

This study will examine sex differences in how the brain processes reward in people that regularly use cannabis. Men and women that use cannabis at least 4 days a week will participate in a study involving 3 in-person visits. The first visit will be used to determine eligibility for the study. The other two visits will last 7 hours each and take place at least two days apart. Visits include administration of either THC, the chemical responsible for many of the psychoactive effects of cannabis, or a placebo; completion of questionnaires; and a 1-hour brain scan. One visit will also include a blood draw for genetic testing.

This study will examine genetic factors that contribute to the different ways people feel after consuming cannabis. People that use cannabis at least 4 days per week will participate in a study involving 1 in-person visit followed by a 5-day remote assessment period. The in-person visit will determine if an individual is eligible for study participation and their blood will be drawn to assess genetics. During the remote assessment period, participants will complete multiple short surveys per day describing their feelings and their recent cannabis use.