The treatment of the depressed phase of
Bipolar Disorder (BPD) is understudied and poses a widespread clinical dilemma. While the use of mood stabilizers in BPD is a common practice, the role of
antidepressants in the depressive phase of the illness remains controversial. This paper reviews the available literature on the subject and highlights the factors essential for making clinical decisions for treating BPD. Most of the standard randomized controlled trials report the efficacy of
antidepressants in the acute phase of BPD, but the data also indicate higher switch rates to
mania and acceleration of mood cycle with their use. Nevertheless, a recent large effectiveness study (STEP-BD) found no superiority or risk of adjunct
antidepressants to a mood stabilizer in the treatment of BPD. In light of the available data, future large clinical studies are essential for elucidating the role of
antidepressants in the treatment of the depressed phase of BPD. Until then, factors such as history of severe
manias, past depression severity and length and rapid cycling will continue to play a role in the decision of clinicians in prescribing
antidepressants for BPD in different phases of the disorder.