Study reveals how booze and weed mess with your driving

NCT ID NCT02709954

Ongoing Knowledge-focused Sponsor: Yale University Source: ClinicalTrials.gov ↗

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

Summary

This study looks at how alcohol and cannabis, alone or together, affect driving and thinking. About 40 occasional users aged 21–55 will take part. They will inhale low-dose THC (like a quarter of a joint) and drink alcohol, then test their driving on a simulator and complete questionnaires. The goal is to better understand the risks of driving under the influence.

What this could mean

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

Active substance: delta-9-THC and ethanol
What this could lead to: If successful, this study could help understand how alcohol and cannabis together impair driving, informing safety guidelines and public policy.
What could go wrong: This is a small, early-phase study with only 40 participants, so results may not apply to everyone. It uses a driving simulator, not real roads, and focuses on occasional users.

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.

cannabis dependence

As listed by the trial registrant

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

ALCOHOL EFFECT CANNABIS DRIVING UNDER THE INFLUENCE OF ALCOHOL AND OTHER DRUGS

Contacts and locations

Locations

Biological Studies Unit, VA Connecticut Healthcare System

West Haven, Connecticut, 06516, United States

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