The goal of the study is to examine how cognitive behavioral therapy (CBT), a common treatment for adolescent depression, affects brain functioning. Depressed adolescents will complete an initial assessment consisting of an interview, questionnaires, computer tasks, and an EEG recording. EEG (electroencephalography) measures brain activity by recording the electrical activity along the scalp caused by the firing of neurons within the brain. They will then complete 12 sessions of cognitive behavioral therapy, which will be 50 minutes long and held once a week for 12 weeks. Before their third therapy session, participants will complete a computer task while EEG data are recorded. After completing the treatment, the participants will complete a final assessment, which will include questionnaires, computer tasks, and an EEG recording. They will also complete follow-up assessments over the phone 1, 3, and 6 months after completing the treatment.