Overview of antidepressants currently used to treat anxiety disorders.

The syndromes of anxiety and depression may reflect separate disorders with overlapping symptoms. They also may be comorbid or reflect illnesses with similar underlying pathophysiology based upon a spectrum of central nervous system dysfunction. Antidepressants effectively treat both anxiety and comorbid anxiety-depression. Tertiary tricyclic antidepressant agents (TCAs) with dual serotonergic-noradrenergic effects, such as imipramine and amitriptyline, appear consistently effective across the anxiety disorders. Selective serotonin reuptake inhibitors (SSRIs) are particularly effective in panic disorder and obsessive-compulsive disorder. SSRIs are similar in efficacy to TCAs but are more tolerable and cause fewer serious adverse events. However, they are relatively slow to act, and efficacy data are limited in states such as generalized anxiety disorder. Newer antidepressants, such as mirtazapine, nefazodone, and venlafaxine XR, may provide some benefits across the broad spectrum of anxiety disorders with the safety and tolerability that are the hallmarks of third generation antidepressants.