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

This study is testing if a combination of L-theanine and paraxanthine can improve attention, impulse control, and thinking skills in adults with ADHD or ASD. Participants will receive either the L-theanine and paraxanthine capsule or a placebo (a capsule with no active ingredients). Researchers will use fMRI (functional magnetic resonance imaging, a type of brain scan) and specific tasks to see if the combination helps. This study is looking for 24 adult men who have been diagnosed with ADHD or ASD by a doctor. The goal is to find out if this combination can be a helpful and affordable treatment option.

Study design
This is a pilot study with 24 adult men, using a randomized, single-blinded, repeated-measures crossover design. This means participants will receive both the active treatment and the placebo at different times, and they won't know which they are receiving.
What's involved
Participants will complete neuropsychological tests, fMRI scans, and fill out self-report measures after taking either the L-theanine-paraxanthine or placebo.
Compensation
Not stated in the trial record.
Follow-up
Cognitive measures are taken 30 minutes after intake of the study intervention at visits 2 or 3.

AI-generated from the public study record. Only the study team can confirm whether you're eligible — confirm details with them before making decisions.

NCT07189442

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

Completed
NAAll AgesInterventional
Texas Tech University Health Sciences Center
~17 participants
Updated 2026-08-24 on ClinicalTrials.gov
What's tested:L-theanine and paraxanthinePlacebo

At a glance

Recruiting sites
0 of 1 listed site is recruiting right now
RecruitingSuspended, closed, or not yet open
What they're measuring
fMRI task-related activity
Measured over At visit 2 or 3, 30 minutes after intake of L-theanine-paraxanthine or placebo.
+2 more outcomes measured
Attention Deficit Hyperactivity Disorder (ADHD)
Autism Spectrum Disorder (ASD)

NCT07189442

Where you'd take part

This study runs at 1 site. They're the same protocol — you choose where, and that choice sets who your contact draft is addressed to.

  • Texas Tech University

    Lubbock, Texasno site contact published

Sites open and close at different times, so the status above is per site — it can differ from the study's overall status.

This trial hasn't published a contact. View it on ClinicalTrials.gov

  • fMRI task-related activityAt visit 2 or 3, 30 minutes after intake of L-theanine-paraxanthine or placebo.

    fMRI task-related activity in default mode and central executive networks during Go/NoGo and Stop-Signal tasks.

  • Stop Signal Reaction TimeAt visit 2 or 3, 30 minutes after intake of L-theanine-paraxanthine or placebo. This task is performed while in the MRI.

    Estimated time (milliseconds) required to inhibit a prepotent response following a stop signal, computed using the horse-race model and drift-diffusion theory. Lower values indicate better inhibitory control.

  • d-prime (sensitivity to the Go signal)At visit 2 or 3, 30 minutes after intake of L-theanine-paraxanthine or placebo. This task is performed while in the MRI.

    d-prime on Go/No-Go task computed using the signal detection theory.