Jun J Maoa,*, Sharon X Xieb, John R Keefec, Irene Soellerd, Qing S Lie, and Jay Amsterdamf
a Integrative Medicine Service, Department of Medicine, Memorial Sloan Kettering Cancer Center,New York, NY
b Department of Biostatistics and Epidemiology, Perelman School of Medicine, University of Pennsylvania, PA
c Department of Psychology, School of Arts and Sciences, University of Pennsylvania, PA
d Department of Family Medicine and Community Health, Perelman School of Medicine, University of Pennsylvania, PA
e Department of Family Medicine and Community Health, Perelman School of Medicine, University of Pennsylvania, PA
f Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, PA
Abstract
Background—Generalized Anxiety Disorder (GAD) is one of the most common anxiety disorders treated in primary care, yet current therapies have limited efficacy and substantial side effects.
Purpose—To evaluate long-term chamomile (Matricaria chamomilla L.) use for prevention of GAD symptom relapse.
Methods—Outpatients from primary care practices and local communities with a primary diagnosis of moderate-to-severe GAD were enrolled for this two-phase study at a large US academic medical center. During Phase 1, eligible participants received 12 weeks of open-label therapy with chamomile pharmaceutical grade extract 1500 mg (500-mg capsule 3 times daily). During Phase 2, treatment responders were randomized to either 26 weeks of continuation chamomile therapy or placebo in a double-blinded, placebo-substitution design. The primary outcome was time to relapse during continuation therapy, analysed using Cox proportional hazards. Secondary outcomes included the proportion who relapsed, treatment-emergent adverse
