Overview Effects of Cognitive Behavioral Therapy on Brain Serotonin Activity in People With Depression Status: Completed Trial end date: 2011-12-01 Target enrollment: Participant gender: Summary This study will examine changes in brain serotonin activity in people with depression before and after they receive cognitive behavioral therapy. Phase: Phase 2/Phase 3 Details Lead Sponsor: University of PennsylvaniaCollaborator: National Institute of Mental Health (NIMH)Treatments: Serotonin