This is a placebo controlled study evaluating the effectiveness of medication in preventing depressive episodes in subjects with a history of Seasonal Affective Disorder (SAD).

Inclusion Criteria:

• Patient has a history of Major Depressive Disorder (MDD) with a seasonal pattern.

Exclusion Criteria:

• Patient has a current or past history of seizure disorder or brain injury.
• Patient has a history or current diagnosis of anorexia nervosa or bulimia.
• Patient has recurrent summer depression more frequently than winter depression.
• Patient has primary diagnosis of panic disorder, Obsessive Compulsive Disorder (OCD), Posttraumatic Stress Disorder (PTSD), acute distress disorder, bipolar II disorder or other psychotic disorders.
• Patient has initiated psychotherapy within the last 3 months.