The acute effects of L-theanine in comparison with alprazolam on anticipatory anxiety in humans
Article first published online: 26 JUL 2004
Copyright © 2004 John Wiley & Sons, Ltd.
Human Psychopharmacology: Clinical and Experimental
Volume 19, Issue 7, pages 457–465, October 2004
How to Cite
Lu, K., Gray, M. A., Oliver, C., Liley, D. T., Harrison, B. J., Bartholomeusz, C. F., Phan, K. L. and Nathan, P. J. (2004), The acute effects of L-theanine in comparison with alprazolam on anticipatory anxiety in humans. Hum. Psychopharmacol. Clin. Exp., 19: 457–465. doi: 10.1002/hup.611
- Issue published online: 20 SEP 2004
- Article first published online: 26 JUL 2004
- Manuscript Accepted: 25 MAY 2004
- Manuscript Received: 29 APR 2004
- anticipatory anxiety;
- anxiety models;
L-Theanine (δ-glutamylethylamide) is one of the predominant amino acids ordinarily found in green tea, and historically has been used as a relaxing agent. The current study examined the acute effects of L-theanine in comparison with a standard benzodiazepine anxiolytic, alprazolam and placebo on behavioural measures of anxiety in healthy human subjects using the model of anticipatory anxiety (AA). Sixteen healthy volunteers received alprazolam (1 mg), L-theanine (200 mg) or placebo in a double-blind placebo-controlled repeated measures design. The acute effects of alprazolam and L-theanine were assessed under a relaxed and experimentally induced anxiety condition. Subjective self-reports of anxiety including BAI, VAMS, STAI state anxiety, were obtained during both task conditions at pre- and post-drug administrations. The results showed some evidence for relaxing effects of L-theanine during the baseline condition on the tranquil–troubled subscale of the VAMS. Alprazolam did not exert any anxiolytic effects in comparison with the placebo on any of the measures during the relaxed state. Neither L-theanine nor alprazalam had any significant anxiolytic effects during the experimentally induced anxiety state. The findings suggest that while L-theanine may have some relaxing effects under resting conditions, neither L-theanine not alprazolam demonstrate any acute anxiolytic effects under conditions of increased anxiety in the AA model. Copyright © 2004 John Wiley & Sons, Ltd.