Peeking inside the ADHD brain: can two drugs rewire attention circuits?

NCT ID NCT03333668

First seen Aug 11, 2026 · Last updated Aug 13, 2026 · Updated 2 times

Summary

This study uses brain scans to compare how a single dose of two ADHD medications—guanfacine (a non-stimulant) and lisdexamfetamine (a stimulant)—affect brain function in children and teens with ADHD, relative to a placebo. Participants perform tasks of attention, working memory, and inhibition while undergoing fMRI. The goal is to understand the distinct brain mechanisms of each drug, which could help tailor ADHD treatments in the future.

What this could mean

Our plain-language read of the trial. This is informational only — not medical advice or a prediction.

Active substance
Guanfacine extended release and lisdexamfetamine dimesylate, compared against placebo
What this could lead to
If successful, this could clarify how these two ADHD drugs work in the brain, potentially guiding more personalized treatment choices.
What could go wrong
This is a small, early-stage brain imaging study, not a treatment trial. Results may not reflect long-term effects or apply broadly to all ADHD patients.

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Conditions

The condition(s) this trial relates to.

As listed by the trial registrant

The condition terms exactly as the trial's registrant entered them.

Contacts and locations

Locations

  • Institute of Psychiatry, Psychology & Neuroscience; King's College London

    London, SE5 8AF, United Kingdom

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Other studies related to the condition(s) this trial covers.