Recruiting

L-theanine and Paraxanthine for Cognitive Improvement in ADHD and ASD

What is being tested

L-theanine and paraxanthine

+ Placebo

Dietary Supplement

Who is being recruted

Autism Spectrum Disorder+4

+ Attention Deficit Disorder with Hyperactivity

+ Autistic Disorder

+8 Eligibility Criteria

See all eligibility criteria

How is the trial designed

Other Study

Interventional

Study Start: October 2025

See protocol details

Summary

Principal SponsorTexas Tech University Health Sciences Center

Study ContactChathurika S Dhanasekara, MD, PhDMore contacts

Last updated: February 6, 2026

Sourced from a government-validated database.Claim as a partner

Study start date: October 1, 2025

Actual date on which the first participant was enrolled.

This study explores a new approach to help individuals with attention-deficit hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) improve their cognitive abilities, such as attention span and impulse control. Traditional medications often come with side effects and high costs, prompting people to look for alternative solutions. This research focuses on the combination of L-theanine, found in tea, and paraxanthine, a metabolite of caffeine, to see if they can safely and effectively enhance cognitive functions without the negative effects commonly associated with caffeine. This study aims to find a more affordable and integrative treatment option that could benefit those affected by ADHD and ASD. Participants in the study will be part of a randomized, single-blinded trial where they will receive oral doses of L-theanine combined with paraxanthine. The study will use advanced imaging techniques to observe changes in brain activity and cognitive performance. The goal is to determine whether this combination can improve sustained attention and reduce mind wandering in adults with ADHD and ASD. While caffeine can cause issues like jitteriness and poor sleep, paraxanthine offers cognitive benefits without these drawbacks, making this study crucial for understanding its potential as a treatment alternative.

Official TitleCombining L-theanine and Paraxanthine for Transient Improvement of Cognitive Deficits Among Patients With Attention Deficit Hyperactivity Disorder and Autism Spectrum Disorder: A Series of Translational Pilot Neuroimaging Studies

NCT07189442

Principal SponsorTexas Tech University Health Sciences Center

Study ContactChathurika S Dhanasekara, MD, PhDMore contacts

Last updated: February 6, 2026

Sourced from a government-validated database.Claim as a partner

Protocol

This section provides details of the study plan, including how the study is designed and what the study is measuring.

Design Details

24 patients to be enrolled

Total number of participants that the clinical trial aims to recruit.

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Some studies explore topics that don't fall into a specific category. These might include innovative research, new technologies, or emerging healthcare areas.

Eligibility

Researchers look for people who fit a certain description, called eligibility criteria: person's general health condition or prior treatments.

Conditions

Criteria

Male

Biological sex of participants that are eligible to enroll.

Healthy volunteers not allowed

If individuals who are healthy and do not have the condition being studied can participate.

Conditions

Pathology

Autism Spectrum DisorderAttention Deficit Disorder with HyperactivityAutistic DisorderMental DisordersChild Development Disorders, PervasiveAttention Deficit and Disruptive Behavior DisordersNeurodevelopmental Disorders

Criteria

2 inclusion criteria required to participate

Adults (18+ years) diagnosed by a physician (per self-report) with ADHD or ASD

Participants with a dual diagnosis and ASD and ADHD will be recruited but will only be included in the ASD group - their concurrent ADHD diagnosis will be included as an additional variable in exploratory analyses

6 exclusion criteria prevent from participating

Subjects who have developed adverse effects when caffeine/paraxanthine /L-theanine/corn starch (will be in placebo) containing products were consumed

Inability to read and follow written instructions

Intake of medications known to have pharmacological interactions with paraxanthine within the past 3 months

Current/past diagnosis of tics or other forms of dyskinesia

Show More Criteria

Study Plan

Find out more about all the medication administered in this study, their detailed description and what they involve.

Treatment Groups

Study Objectives

2 intervention groups are designated in this study

This study does not include a placebo group

Treatment Groups

Group I

Experimental

A group of 12 adult males with Attention Deficit Hyperactivity Disorder (ADHD) will be enrolled. Each participant will receive both study conditions in a randomized, single-blinded, repeated-measures crossover design: Active Condition: One capsule containing 200 mg L-theanine + 200 mg paraxanthine. Placebo Condition: One capsule containing 400 mg of corn starch. The order of administration will be randomized, with each participant completing both conditions on separate visits (visits 2 and 3).

Group II

Experimental

A group of 12 adult males with autism spectrum disorder (ASD) will be enrolled. Each participant will receive both study conditions in a randomized, single-blinded, repeated-measures crossover design: Active Condition: One capsule containing 200 mg L-theanine + 200 mg paraxanthine. Placebo Condition: One capsule containing 400 mg of corn starch. The order of administration will be randomized, with each participant completing both conditions on separate visits (visits 2 and 3).

Study Objectives

Primary Objectives

Study Centers

These are the hospitals, clinics, or research facilities where the trial is being conducted. You can find the location closest to you and its status.

This study has 1 location

Recruiting

Texas Tech University

Lubbock, United StatesOpen Texas Tech University in Google Maps

Recruiting

One Study Center