Mental Health Service, Ralph H. Johnson Veterans Affairs Medical Center, and Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston (Gros); Anxiety Treatment and Research Clinic (Merrifield, Hewitt, Elcock, Rowa, McCabe), and Mood Disorders Outpatient Clinic (Merrifield), St. Joseph's Healthcare, Hamilton, Ontario, Canada; Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton (Merrifield, Hewitt, Rowa, McCabe).