• Depressive relapse [ Time Frame: Measured at Month 9 ] [ Designated as safety issue: No ]
  

• Psychosocial functioning [ Time Frame: Measured at Month 9 ] [ Designated as safety issue: No ]
  

Cognitive therapy (CT) is a form of therapy that focuses on changing negative thinking patterns and developing coping skills to deal with psychological problems. It encourages individuals to think, feel, and behave in a more positive manner. Previous research has shown that CT is effective for treating a number of psychological symptoms, including anxiety, anger, and loneliness. Many studies show that CT is, in fact, more effective than antidepressant medications for treating various psychological disorders. The "self-help" mentality and coping skills that are developed during CT tend to decrease the likelihood of depression relapse. While antidepressants often cause many unpleasant side effects such as dizziness, nausea, and increased heart rate, there are no known negative side effects associated with CT. The purpose of this study is to evaluate the effectiveness of CT versus antidepressant medication for treating depression and preventing relapse in individuals with recurrent depression.

This 36-month study will consist of three phases. During Months 1 through 3, participants will receive between 16 and 20 CT sessions. Participants will then be randomly assigned to receive additional CT sessions, antidepressant medication, or placebo for 8 months. Upon completing treatment, follow-up visits will occur once every 4 months for a total of 24 months. Outcome measurements will include standardized psychological tests and questionnaires to assess the participant's level of depression. All measurements will be assessed at Week 1, Week 12, and Months 8, 12, 16, 20, and 24.

Inclusion Criteria:

• Recurrent unipolar major depressive disorder
• At least two episodes of major depression
• At least one period of recovery during a depressive episode or a history of dysthymia (a mood disorder characterized by depression) prior to the onset of current or past depressive episodes
• Able to speak and read English

Exclusion Criteria:

• Active alcohol or other substance dependence within 6 months prior to study entry
• Currently at risk for suicide
• Current mood disorders due to a medical condition or substance abuse
• Bipolar, schizoaffective, obsessive compulsive, or eating disorders
• Schizophrenia
• Unable to stop mood-altering medications
• Current use of a medication that might cause depression
• Diagnosis of a medical disorder that may cause depression (e.g., diabetes, head injury, stroke, cancer, multiple sclerosis)
• Previous failure to experience a reduction in depressive symptoms after 6 weeks of 40 mg of Prozac
• Pregnant or planning to become pregnant in the next 11-12 months
• Unable to attend clinic twice weekly during business hours