L-theanine in the adjunctive treatment of generalized anxiety disorder: A double-blind, randomised, placebo-controlled trial

Publication date: March 2019Source: Journal of Psychiatric Research, Volume 110Author(s): Jerome Sarris, Gerard J. Byrne, Lachlan Cribb, Georgina Oliver, Jenifer Murphy, Patricia Macdonald, Sonia Nazareth, Diana Karamacoska, Samantha Galea, Anika Short, Carolyn Ee, Yoann Birling, Ranjit Menon, Chee H. NgAbstractPartial or non-response to antidepressants in Generalized Anxiety Disorder (GAD) is common in clinical settings, and adjunctive biological interventions may be required. Adjunctive herbal and nutraceutical treatments are a novel and promising treatment option. L-theanine is a non-protein amino acid derived most-commonly from tea (Camellia sinensis) leaves, which may be beneficial in the treatment of anxiety and sleep disturbance as suggested by preliminary evidence. We conducted a 10-week study (consisting of an 8-week double-blind placebo-controlled period, and 1-week pre-study and 2-week post-study single-blinded observational periods) involving 46 participants with a DSM-5 diagnosis of GAD. Participants received adjunctive L-theanine (450–900 mg) or matching placebo with their current stable antidepressant treatment, and were assessed on anxiety, sleep quality, and cognition outcomes. Results revealed that adjunctive L-theanine did not outperform placebo for anxiety reduction on the HAMA (p = 0.73) nor insomnia severity on the Insomnia Severity Index (ISI; p = 0.35). However, LT treated participants reported greater self-reported sleep satisfaction than ...
Source: Journal of Psychiatric Research - Category: Psychiatry Source Type: research