The primary objective of the study is to determine whether quetiapine extended-release in combination with cognitive behavioral therapy (CBT) is more effective than CBT plus placebo in treating depressive and anxiety symptoms in patients with both major depression and generalized anxiety disorder. Approximately 64 individuals (adults 18-65) will be randomly assigned to treatment group for 16 weeks. Weekly CBT sessions will be conducted lasting about 45 minutes and weekly visits with the study psychiatrist lasting about 20 minutes in which medication will be discussed. Both clinician administered and self-report measures will be used to compare groups before and after 16 weeks.