1. Outpatient males and females 18 65 years of age (inclusive).
2. Diagnostic and Statistical Manual of Mental Disorders Fourth edition Text Revised (DSM
IV TR) diagnosis of GAD (DSM IV TR, 300.02), confirmed as primary diagnosis by the
Mini international neuropsychiatric interview (MINI) structured interview.
3. All subjects must have a total HAM A (via SIGH A) score 22 at screening. In addition,
scores at the baseline visit must also be within 20% of scores at screening.
4. Subjects must also have a Covi Anxiety Scale score of 9 and a Raskin Depression Scale
score 7 at the Screening (Visit 1) visit to ensure predominance of anxiety symptoms
over depression symptoms.
5. Taking an FDA approved GAD treatment (escitalopram 10 to 20 mg total daily dose,
paroxetine 20 to 50 mg total daily dose, duloxetine 60 to 120 mg total daily dose, or
venlafaxine 75 to 225 mg total daily dose) at a stable FDA approved dosage for at
least the two consecutive months in the current episode immediately prior to the
screening visit. Sertraline or citalopram are also permitted as background treatment
for GAD at doses of 50 to 200 mg total daily dose and 20 to 40 mg total daily dose,
1. Subjects with a history of daily benzodiazepine use within one month of the screening
2. Recent (defined as meeting disorder diagnostic criteria during the last 6 months) of a
DSM IV TR Axis I diagnosis other than generalized anxiety disorder, with the following
exceptions: a. Subjects with recent (in the last 2 months) major depressive disorder
may be enrolled if the anxiety symptoms are predominant over the depressive symptoms,
as judged by the Covi/Raskin criteria listed above and confirmed GAD as the primary
diagnosis by the MINI structured interview. b. Comorbid social phobia and/or specific
phobias are permitted as long as the anxiety symptoms due to these disorders are
clinically less significant than the anxiety symptoms due to GAD and GAD is confirmed
as the primary diagnosis by the MINI structured interview.
3. Recent (defined as meeting disorder diagnostic criteria during the last 6 months) of a
DSM IV TR Axis I of panic disorder with or without agoraphobia, Post Traumatic Stress
Disorder (PTSD), dissociative disorder, obsessive compulsive disorder, attention
deficit disorder. If a subject has a past misdiagnosis of any of these disorders, or
if the subject has another psychiatric disorder that in the opinion of the
investigator affects the suitability of a subject for this study based on safety or
other considerations, the investigator will need to contact the sponsor prior to
4. Past and/or current DSM IV TR diagnosis of schizophrenia, schizoaffective disorder,
other psychotic disorders, bipolar disorders (I or II), factitious disorder or
cognitive disorder (including delirium, dementia, and amnestic disorder).
5. Presence of comorbid personality disorders (Axis II) based on DSM IV TR.
6. Subjects who meet DSM IV TR defined diagnostic criteria for psychoactive substance
dependence (excluding nicotine dependence) within 12 months of screening or DSM IV TR
defined substance abuse within 3 months prior to screening.