Venlafaxine extended release (ER) in the treatment of generalised anxiety disorder: twenty-four-week placebo-controlled dose-ranging study.

Background: Generalised anxiety disorder (GAD) has received less study than other anxiety disorders, particularly its long-term treatment.

Aims: To assess the efficacy and safety of venlafaxine extended release (ER) in patients with GAD.

Method: A total of 541 out-patients, 18-86 years old, were recruited to this 24-week, placebo-controlled, double-blind study of three fixed doses (37.5, 75 and 150 mg/day) of venlafaxine ER.

Results: All doses of venlafaxine ER showed efficacy superior to placebo, apparent from week 2, that was sustained throughout the 24-week study for the two higher doses. The discontinuation rate did not differ significantly among the treatment groups.

Conclusions: Venlafaxine ER is an effective and safe treatment for GAD for up to 6 months.