Which of the following medications is effective for treating both depression and anxiety disorders?

Venlafaxine, marketed as Effexor, is a serotonin-norepinephrine reuptake inhibitor (SNRI) that is particularly effective for treating both depression and anxiety disorders. It works by increasing the levels of serotonin and norepinephrine in the brain, which can effectively alleviate symptoms of both conditions. Clinical evidence supports its efficacy in reducing depression symptoms as well as treating generalized anxiety disorder and social anxiety disorder.

Citalopram, while effective for depression, is primarily a selective serotonin reuptake inhibitor (SSRI) and does not have as pronounced an effect on anxiety disorders compared to other options. Paroxetine, another SSRI, is effective for anxiety disorders but has different dosing and side effect profiles compared to SNRIs. Desvenlafaxine, similar to Venlafaxine, is an SNRI but may not have the same breadth of evidence supporting its combined use for both depression and anxiety as Venlafaxine does. Therefore, Venlafaxine is recognized for its dual efficacy in treating these conditions, which is why it is the most appropriate choice.