Trial reportScientific reports2020
Effects of L-theanine-caffeine combination on sustained attention and inhibitory control among children with ADHD: a proof-of-concept neuroimaging RCT.
Trial report in Scientific reports, 2020. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 17 papers, 5 of them syntheses that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
17 citing papers in PubMed, 5 syntheses or guidelines pooled it, 36 citations in OpenAlex.
- Cognitive and affective effects of L-Theanine: a systematic review and meta-analysis of 31 randomized trials.Molecular psychiatry · 2026Pooled it
- Pooled it
- Efficiency of Different Supplements in Alleviating Symptoms of ADHD with or Without the Use of Stimulants: A Systematic Review.Nutrients · 2025Pooled it
- The effects of L-theanine supplementation on the outcomes of patients with mental disorders: a systematic review.BMC psychiatry · 2024Pooled it
- Pooled it
- Sex-specific effects of chronic caffeine on impulsive choice and serotonergic markers in an ADHD rat model.Psychopharmacology · 2026Article
- Clinical assessment of blood glucose responses to 300-mg dose of L-theanine, an amino acid unique to green tea, in a fixed-sequence, two-period trial.Journal of pharmaceutical health care and sciences · 2026Article
- Effects of L-theanine on cognition, mood and sleep: evidence from human trials.Frontiers in nutrition · 2026Review
- Pharmaceutical Activities of Theanine: A Phytochemical Nutrient.Food science & nutrition · 2025Review
- L-Theanine Ameliorates Obesity-Related Complications Induced by High-Fat Diet in Mice: Insights from Transcriptomics and Metabolomics.Foods (Basel, Switzerland) · 2024Article
- Central Executive and Default Mode Networks: An Appraisal of Executive Function and Social Skill Brain-Behavior Correlates in Youth with Autism Spectrum Disorder.Journal of autism and developmental disorders · 2024Article
- Exploring causal associations of antioxidants from supplements and diet with attention deficit/hyperactivity disorder in European populations: a Mendelian randomization analysis.Frontiers in nutrition · 2024Article
- Effects of Caffeine on Main Symptoms in Children with ADHD: A Systematic Review and Meta-Analysis of Randomized Trials.Brain sciences · 2023Review
- Association between urinary caffeine and caffeine metabolites and stroke in American adults: a cross-sectional study from the NHANES, 2009-2014.Scientific reports · 2023Article
- L-Theanine: A Unique Functional Amino Acid in Tea (Frontiers in nutrition · 2022Review
- Review
- A Novel Knowledge Distillation-Based Feature Selection for the Classification of ADHD.Biomolecules · 2021Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
7 authors at 4 institutions in 3 countries.
Funding
No grant is acknowledged in the PubMed record.
Abstract
We examined the acute effects of L-theanine, caffeine and their combination on sustained attention, inhibitory control and overall cognition in boys with attention deficit hyperactivity disorder (ADHD). L-Theanine (2.5 mg/kg), caffeine (2.0 mg/kg), their combination and a placebo were administered in a randomized four-way repeated-measures crossover with washout, to five boys (8-15 years) with ADHD. Functional magnetic resonance imaging (fMRI) was performed during a Go/NoGo task and a Stop-signal task ~ 1 h post-dose. NIH Cognition Toolbox was administered ~ 2 h post-dose. Treatment vs. placebo effects were examined in multi-level mixed-effects models. L-Theanine improved total cognition composite in NIH Cognition Toolbox (p = 0.040) vs. placebo. Caffeine worsened and L-theanine had a trend of worsening inhibitory control (i.e. increased Stop-signal reaction time; p = 0.031 and p = 0.053 respectively). L-Theanine-caffeine combination improved total cognition composite (p = 0.041), d-prime in the Go/NoGo task (p = 0.033) and showed a trend of improvement of inhibitory control (p = 0.080). L-Theanine-caffeine combination was associated with decreased task-related reactivity of a brain network associated with mind wandering (i.e. default mode network). L-Theanine-caffeine combination may be a potential therapeutic option for ADHD-associated impairments in sustained attention, inhibitory control and overall cognitive performance.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.