Participants will be divided into two groups. Group 1 will consist of 20 individuals diagnosed with marijuana dependence; Group 2 will consist of individuals matched by age range, gender and race to Group 1, and who are healthy volunteers and do not use marijuana or who report limited marijuana exposure. Participants in Group 1 will spend one night at the Psychiatric and Addiction Research Center at Detroit Receiving Hospital to control for alcohol and drug use for 12 hours preceding the next day's 2-hour study session. Participants in Group 2 are not required to spend the night, but are tested for drugs and alcohol prior to the session. During the study session, both groups will be shown a nature video and will be asked to handle and smell various items; these will act as the neutral, non marijuana-related cues. Next, the participants will watch a video of individuals smoking marijuana and will be asked to handle and smell marijuana-related items; these will act as the marijuana-related cues. Heart rate and skin temperature will be monitored continuously throughout the cue sessions with the use of electrodes and a skin thermometer. Prior to and after the cue sessions, blood pressure will be measured and questionnaires will be administered to assess drug cravings as well as related mood states. Prior to leaving the laboratory, the participants' vital signs will be evaluated to ensure that any cue-related physiological changes have returned to normal. Participants will have the option of talking to a clinician experienced in dealing with drug cravings following the end of the study session.