Long-term treatment strategies in anxiety disorders.

Anxiety disorders are prevalent and associated with increased morbidity and mortality. Some chronic anxiety disorders, including generalized anxiety disorder (GAD), may be characterized by an underlying high level of anxiety on which exacerbations of symptoms are superimposed. Effective treatment of anxiety disorders should therefore strive to attain both an acute reduction in the symptoms of anxiety (a response) and sustained resolution of the symptoms of any underlying chronic anxiety (remission). This strategy may necessitate long-term treatment of these disorders by pharmacotherapy and/or psychotherapy. Studies using the serotonin and norepinephrine reuptake inhibitor (SNRI), venlafaxine extended release (XR), suggest that these aims may be achieved using this newer class of drugs. Studies with venlafaxine XR in patients with GAD have demonstrated robust anxiolytic efficacy over placebo, particularly regarding worry, cognitive dysfunction, and muscular tension, which are specific to GAD. Administration of venlafaxine XR over both short- (8-week) and long-term (6-month) periods resulted in a significantly greater number of patients achieving response and remission than obtained with placebo. Long-term treatment with venlafaxine XR in patients with GAD showed greater efficacy than that observed in short-term studies. This was achieved without any loss of short-term efficacy and patients' social functioning was also restored. While available data indicate that venlafaxine XR is an appropriate choice of agent in the long-term treatment of GAD, more studies are needed to determine how to further increase remission rates and to maintain remission beyond 6 months.