Changes in BDNF serum levels in patients with major depression disorder (MDD) after 6 months treatment with sertraline, escitalopram, or venlafaxine.

Recent studies have implicated brain-derived neurotrophic factor (BDNF) in the pathophysiology of depression and the activity of antidepressant drugs. Serum BDNF levels are lower in depressed patients, and increase in response to antidepressant medication. However, how BDNF responds to different classes of antidepressant drugs is unknown.