Pregabalin in the Treatment of Patients With Generalized Anxiety Disorder (GAD).

• Drug: pregabalin
  
  pregabalin 150-600 mg/day flexibly dosed for the first 6 weeks and fixed dosed for the last 2 weeks of total 8 weeks of double blind study period, + concurrent GAD treatment from the open-label study period
  Other Name: Lyrica
• Drug: placebo
  
  placebo + concurrent GAD treatment from the open-label study period

• Placebo Comparator: Arm 2
  
  Intervention: Drug: placebo
• Experimental: Arm 1
  
  Intervention: Drug: pregabalin

Inclusion Criteria:

• Adult male and female subjects with primary DSM-IV diagnosis of GAD, as confirmed by the MINI structured interview.
• Historical failure to respond optimally to a GAD treatment

Exclusion Criteria:

• Current primary DSM-IV (Diagnostic and Statistical Manual of Mental Disorders 4th edition) diagnosis of major depressive disorder with or without seasonal pattern, dysthmic disorder, depressive disorder NOS (not otherwise specified), social phobia, panic disorder with or without agoraphobia, post traumatic stress disorder, dissociative disorder, borderline personality disorder, obsessive-compulsive disorder, antisocial personality disorder, as defined in the DSM-IV TR (Diagnostic and Statistical Manual of Mental Disorders 4th edition, Text Revision).
• Past and/or current DSM-IV diagnosis of schizophrenia, schizoaffective disorder, other psychotic disorders, bipolar disorders (I or II), factitious disorder or cognitive disorder (including delirium, dementia, and amnestic disorder).