Which mood stabilizer is commonly used to treat Bipolar Disorder?

Lamotrigine is a well-established mood stabilizer that is particularly effective in the treatment of Bipolar Disorder, especially for the maintenance phase and in preventing depressive episodes. It works by modulating neurotransmitter release and stabilizing mood fluctuations which are characteristic of bipolar disorder.

Unlike some of the other options provided, which are primarily antidepressants used to treat unipolar depression and anxiety disorders, Lamotrigine's specific action on mood stability makes it a critical component of bipolar disorder management. Its efficacy in reducing the frequency of mood swings and its safety profile contribute to its prominence in treating this condition.

In contrast, Fluoxetine, Paroxetine, and Sertraline are selective serotonin reuptake inhibitors (SSRIs) that can lead to manic episodes if used alone in patients with bipolar disorder. Therefore, they are not recommended for treating bipolar disorder unless used in conjunction with a mood stabilizer to mitigate the risk of inducing mania.