Preclinical and clinical findings indicate that LEV has some anxiolytic potential. There is reason to believe that compounds with anxiolytic activity may have broad clinical utility across the anxiety spectrum. This trial was intended to explore LEV's utility in adults with social anxiety disorder.

Inclusion Criteria:

• Male or female outpatients between 18 and 70 years old inclusive;
• symptoms of social anxiety disorders (generalized type) present for at least 1 year prior to Selection Visit;
• had a score of >=60 on the LSAS at the Selection Visit and at the Randomization Visit. Additionally, the clinician's gloal impression of change score must have been >= 2 at the Randomization Visit;
• had a telephone where they could be directly contacted.

Exclusion Criteria:

• History of autism or Asperger's Disease;
• had another primary axis I disorder or fulfilled diagnostic and statistical manual of mental disorders-4th edition (DSM-IV) criteria in the 6 months prior to Screening;
• major depression as measured by a Hamilton Depression Rating Scale (HAM-D-17 items) total score of > 17 and/or a suicide subscale score on the HAM-D-17 items of > 2 at the Selection or Randomization Visit;
• history of electroconvulsive therapy within the prior 3 months;
• history of psychotherapy which was not stable and ongoing for at least 6 months prior to Visit 1;
• clinical history of significantly impaired renal function with an estimated creatinine clearance below 80 mL/min;
• clinically significant medical condition;
• history of any clinically significant allergic condition or allergy to LEV or pyrrolidone derivatives;
• neutrophil count of less than 1800/µL.