This study will evaluate the efficacy and safety of PD 0332334 for the treatment of generalized anxiety disorder.

Inclusion Criteria:

• Diagnosis of GAD (Diagnostic and Statistical Manual-IV [DSM-IV], 300.02) as established by the clinician (psychiatrist or licensed clinical psychologist) who has interviewed the subject using all sources of data including the Mini International Neuropsychiatric Interview (MINI) for DSM-IV Axis I disorders and other clinical information. Subjects with specific phobia(s) (as defined in DSM-IV) or dysthymic disorder will be allowed in the study.
• Subjects must have a HAM-A total score ≥20 at the screening (V1) and randomization (V2) visits. Subjects must also have a Covi Anxiety Scale score of >9 and a Raskin Depression Scale score <7 at the Screening (V1) visit to ensure predominance of anxiety symptoms over depression symptoms.

Exclusion Criteria:

• Subjects with evidence or history of clinically significant hematological, renal, endocrine, pulmonary, gastrointestinal, cardiovascular, hepatic, pancreatic, neurologic, active infections, immunological, or allergic disease (including drug allergies).
• Any of the following current (within the past 6 months through the present) DSM-IV Axis I diagnoses: Major depressive disorder, Obsessive compulsive disorder, Panic disorder; Agoraphobia, Posttraumatic stress disorder, Anorexia, Bulimia, Caffeine-induced anxiety disorder, Alcohol or substance abuse or dependence unless in full remission for at least 6 months, Social anxiety disorder.
• Any of the following past or current DSM IV Axis I diagnoses: Schizophrenia, Psychotic disorder, Delirium, dementia, amnestic, and other clinically significant cognitive disorders, Bipolar or schizoaffective disorder, Cyclothymic disorder, Dissociative disorders.
• Antisocial or borderline personality disorder.
• Serious suicidal risk per the clinical investigator's judgment.