Could a Parkinson's drug help with alcohol and ADHD?

NCT ID NCT03904498

Completed Disease control Sponsor: University of Colorado, Denver Source: ClinicalTrials.gov ↗

First seen Jun 25, 2026 · Last updated Jun 27, 2026 · Updated 1 time

Summary

This study tested whether tolcapone, a drug used for Parkinson's disease, could change how people with both alcohol use disorder and ADHD respond to alcohol and make decisions. 23 adults completed the trial, which involved taking tolcapone or a placebo and then undergoing alcohol challenges, brain scans, and decision-making tests. The goal was to see if the drug affects alcohol cravings, intoxication, and brain activity related to attention and impulse control.

What this could mean

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

Active substance: Tolcapone (Tasmar)
What this could lead to: If it works, this could point toward a new treatment option for people with both alcohol use disorder and ADHD.
What could go wrong: This was a small, early-phase study with only 23 participants. Results may not apply to everyone, and tolcapone has known liver risks.

This is an AI summary of the original study and may miss details. Read our disclaimer.

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Conditions

The condition(s) this trial relates to.

alcohol abuse attention deficit hyperactivity disorder, inattentive type attention deficit-hyperactivity disorder

As listed by the trial registrant

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

ALCOHOL USE DISORDER ATTENTION DEFICIT HYPERACTIVITY DISORDER

Contacts and locations

Locations

University of Colorado Anschutz Medical Campus

Aurora, Colorado, 80045, United States

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