Abstract
Partial 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 placebo (ISI item 4; p = 0.015). Further, a separation in favour of L-theanine was noted on the ISI in those with non-clinical levels of insomnia symptoms (ISI ≤ 14; p = 0.007). No significant cognitive effects (trail making time and the modified emotional Stroop) were revealed. While this preliminary study did not support the efficacy of L-theanine in the treatment of anxiety symptoms in GAD, further studies to explore the application of L-theanine in sleep disturbance are warranted.
| Original language | English |
|---|---|
| Pages (from-to) | 31-37 |
| Number of pages | 7 |
| Journal | Journal of Psychiatric Research |
| Volume | 110 |
| Early online date | 8 Dec 2018 |
| DOIs | |
| Publication status | Published - Mar 2019 |
| Externally published | Yes |
Keywords
- Anxiety
- GAD
- L-theanine
- Randomised controlled trial
- Sleep
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Sarris, J., Byrne, G. J., Cribb, L., Oliver, G., Murphy, J., Macdonald, P., Nazareth, S., Karamacoska, D., Galea, S., Short, A., Ee, C., Birling, Y., Menon, R., & Ng, C. H. (2019). L-theanine in the adjunctive treatment of generalized anxiety disorder: A double-blind, randomised, placebo-controlled trial. Journal of Psychiatric Research, 110, 31-37. https://doi.org/10.1016/j.jpsychires.2018.12.014
Sarris, Jerome ; Byrne, Gerard J. ; Cribb, Lachlan et al. / L-theanine in the adjunctive treatment of generalized anxiety disorder : A double-blind, randomised, placebo-controlled trial. In: Journal of Psychiatric Research. 2019 ; Vol. 110. pp. 31-37.
@article{8d9c218781c84ad6918c7db60e5481ff,
title = "L-theanine in the adjunctive treatment of generalized anxiety disorder: A double-blind, randomised, placebo-controlled trial",
abstract = "Partial 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 placebo (ISI item 4; p = 0.015). Further, a separation in favour of L-theanine was noted on the ISI in those with non-clinical levels of insomnia symptoms (ISI ≤ 14; p = 0.007). No significant cognitive effects (trail making time and the modified emotional Stroop) were revealed. While this preliminary study did not support the efficacy of L-theanine in the treatment of anxiety symptoms in GAD, further studies to explore the application of L-theanine in sleep disturbance are warranted.",
keywords = "Anxiety, GAD, L-theanine, Randomised controlled trial, Sleep",
author = "Jerome Sarris and Byrne, {Gerard J.} and Lachlan Cribb and Georgina Oliver and Jenifer Murphy and Patricia Macdonald and Sonia Nazareth and Diana Karamacoska and Samantha Galea and Anika Short and Carolyn Ee and Yoann Birling and Ranjit Menon and Ng, {Chee H.}",
year = "2019",
month = mar,
doi = "10.1016/j.jpsychires.2018.12.014",
language = "English",
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Sarris, J, Byrne, GJ, Cribb, L, Oliver, G, Murphy, J, Macdonald, P, Nazareth, S, Karamacoska, D, Galea, S, Short, A, Ee, C, Birling, Y, Menon, R & Ng, CH 2019, 'L-theanine in the adjunctive treatment of generalized anxiety disorder: A double-blind, randomised, placebo-controlled trial', Journal of Psychiatric Research, vol. 110, pp. 31-37. https://doi.org/10.1016/j.jpsychires.2018.12.014
L-theanine in the adjunctive treatment of generalized anxiety disorder: A double-blind, randomised, placebo-controlled trial. / Sarris, Jerome; Byrne, Gerard J.; Cribb, Lachlan et al.
In: Journal of Psychiatric Research, Vol. 110, 03.2019, p. 31-37.
Research output: Contribution to journal › Article › peer-review
TY - JOUR
T1 - L-theanine in the adjunctive treatment of generalized anxiety disorder
T2 - A double-blind, randomised, placebo-controlled trial
AU - Sarris, Jerome
AU - Byrne, Gerard J.
AU - Cribb, Lachlan
AU - Oliver, Georgina
AU - Murphy, Jenifer
AU - Macdonald, Patricia
AU - Nazareth, Sonia
AU - Karamacoska, Diana
AU - Galea, Samantha
AU - Short, Anika
AU - Ee, Carolyn
AU - Birling, Yoann
AU - Menon, Ranjit
AU - Ng, Chee H.
PY - 2019/3
Y1 - 2019/3
N2 - Partial 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 placebo (ISI item 4; p = 0.015). Further, a separation in favour of L-theanine was noted on the ISI in those with non-clinical levels of insomnia symptoms (ISI ≤ 14; p = 0.007). No significant cognitive effects (trail making time and the modified emotional Stroop) were revealed. While this preliminary study did not support the efficacy of L-theanine in the treatment of anxiety symptoms in GAD, further studies to explore the application of L-theanine in sleep disturbance are warranted.
AB - Partial 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 placebo (ISI item 4; p = 0.015). Further, a separation in favour of L-theanine was noted on the ISI in those with non-clinical levels of insomnia symptoms (ISI ≤ 14; p = 0.007). No significant cognitive effects (trail making time and the modified emotional Stroop) were revealed. While this preliminary study did not support the efficacy of L-theanine in the treatment of anxiety symptoms in GAD, further studies to explore the application of L-theanine in sleep disturbance are warranted.
KW - Anxiety
KW - GAD
KW - L-theanine
KW - Randomised controlled trial
KW - Sleep
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JO - Journal of Psychiatric Research
JF - Journal of Psychiatric Research
ER -
Sarris J, Byrne GJ, Cribb L, Oliver G, Murphy J, Macdonald P et al. L-theanine in the adjunctive treatment of generalized anxiety disorder: A double-blind, randomised, placebo-controlled trial. Journal of Psychiatric Research. 2019 Mar;110:31-37. Epub 2018 Dec 8. doi: 10.1016/j.jpsychires.2018.12.014
