Escitalopram is a potent and highly selective SSRI, whose efficacy and safety in the treatment of MDD have recently been established. This study compared the efficacy and safety of escitalopram to placebo in outpatients with SAD (DSM-IV criteria) with a baseline LSAS >=70 and a CGI-S >=4. After a l-week, single-blind placebo period, patients were randomised to 12 weeks of double-blind treatment with lOmg/day escitalopram (n=181) or placebo (n=l77), with the option of having their dosage doubled after 4,6, or 8 weeks of treatment. The primary efficacy analysis of mean change in LSAS total score from baseline showed a statistically significantly better therapeutic effect for escitalopram versus placebo. Additional efficacy analyses also showed a significantly better therapeutic effect for escitalopram versus placebo on the measures of CGI-S, CGI-I, LSAS avoidance and fear/anxiety, and 2 of 3 items on the Sheehan Disability Scale (SDS). Escitalopram was well tolerated in this patient population. This phase III study is the first study to demonstrate the efficacy and good tolerability of escitalopram in treating patients with SAD.