Does tachyphylaxis occur after repeated antidepressant exposure in patients with Bipolar II major depressive episode?
Tachyphylaxis often refers to the loss of antidepressant efficacy during long-term treatment. However, it may also refer to the gradual loss of efficacy after repeated antidepressant exposures over time. The aim of this study was to examine the phenomenon of tachyphylaxis in patients with Bipolar II major depression treated with either venlafaxine or lithium. We hypothesized that a greater number of prior antidepressant exposures would result in a reduced response to venlafaxine, but not lithium, therapy.