 The participant will view the same images he or she did on the previous day Visit 2, and may experience the same aversive stimulus as during Visit 2. The participant will again be asked to rate how much he or she expects to experience the aversive stimulus after each image and he or she will also be asked to report his or her level of anxiety on a scale from 0 to 100. However, about 2 hours before the task begins, the participant will be asked to swallow a capsule containing either a marijuana-like drug Dronabinol or a placebo sugar pill. Dronabinol is a Food Drug Administration FDA approved drug and the doses 5mg or 10mg; one time are unlikely to have any effects that last beyond the duration of the study visit. About every 30 minutes after taking the pill, the participant will fill out some questionnaires about mood and how he or she is feeling at the moment. 