Cannabis-based medicine for tic disorders did not impair driving and may have actually improved it

In a randomized trial, nabiximols treatment for tic disorders did not impair driving fitness, and more patients improved from unfit to fit to drive compared to placebo.

Müller-Vahl, Kirsten R et al.·Cannabis and cannabinoid research·2024·Strong EvidenceRandomized Controlled Trial
RTHC-05574Randomized Controlled TrialStrong Evidence2024RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Randomized Controlled Trial
Evidence
Strong Evidence
Sample
N=64

What This Study Found

Fitness to drive increased from 55.8% to 71.8% in the nabiximols group over 13 weeks, while it decreased from 66.7% to 52.6% in placebo. Only 8.3% of fit nabiximols patients became unfit versus 28.6% in placebo. 42.1% of unfit nabiximols patients improved to fit versus 28.6% in placebo.

Key Numbers

64 patients. Nabiximols: fit to drive rose from 55.8% to 71.8%. Placebo: fell from 66.7% to 52.6%. Risk difference: 0.17 favoring nabiximols. 42.1% of initially unfit nabiximols patients became fit.

How They Did This

Substudy of the CANNA-TICS phase IIIb RCT. 64 patients with Tourette syndrome or chronic tic disorders assessed with computerized driving fitness tests at baseline and week 13.

Why This Research Matters

The fear that cannabis-based medicines impair driving is a major prescribing barrier. This study shows that for tic disorder patients, nabiximols improved driving-relevant skills by reducing the tics that themselves impair driving.

The Bigger Picture

When a medicine treats a condition that itself impairs driving, the net effect may be positive. Policy restricting all cannabis users from driving may paradoxically make these patients less safe by denying effective treatment.

What This Study Doesn't Tell Us

64 patients at two sites. Computerized test is a proxy for real driving. Tic disorder population may not generalize. 13-week timeframe.

Questions This Raises

  • ?Would similar improvements be seen with nabiximols for MS spasticity?
  • ?Should driving fitness testing be part of medical cannabis monitoring?

Trust & Context

Key Stat:
of initially unfit patients became fit to drive after 13 weeks of nabiximols for tic disorders
Evidence Grade:
Substudy of a well-designed phase IIIb RCT with objective computerized assessment. Small sample at two sites.
Study Age:
2024 publication from the CANNA-TICS trial.
Original Title:
The Effect of Nabiximols on Driving Ability in Adults with Chronic Tic Disorders: Results of a Substudy Analysis of the Double-Blind, Randomized, Placebo-Controlled CANNA-TICS Trial.
Published In:
Cannabis and cannabinoid research, 9(5), 1349-1359 (2024)
Database ID:
RTHC-05574

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled TrialGold standard for testing treatments
This study
Cohort / Case-Control
Cross-Sectional / Observational
Case Report / Animal Study

Participants are randomly assigned to treatment or placebo groups to test cause and effect.

What do these levels mean? →

Frequently Asked Questions

Does medical cannabis impair driving?

In this study of tic disorder patients, nabiximols actually improved driving fitness by reducing the tics that interfere with vehicle control.

Why would a cannabis medicine improve driving?

Tics cause sudden involuntary movements. By reducing tic severity, nabiximols removed a source of driving impairment, resulting in net improvement despite containing THC.

Read More on RethinkTHC

Cite This Study

RTHC-05574·https://rethinkthc.com/research/RTHC-05574

APA

Müller-Vahl, Kirsten R; Pisarenko, Anna; Ringlstetter, Rieke; Cimpianu, Camelia-Lucia; Fremer, Carolin; Weidinger, Elif; Jenz, Eva Beate; Musil, Richard; Brunnauer, Alexander; Großhennig, Anika. (2024). The Effect of Nabiximols on Driving Ability in Adults with Chronic Tic Disorders: Results of a Substudy Analysis of the Double-Blind, Randomized, Placebo-Controlled CANNA-TICS Trial.. Cannabis and cannabinoid research, 9(5), 1349-1359. https://doi.org/10.1089/can.2023.0114

MLA

Müller-Vahl, Kirsten R, et al. "The Effect of Nabiximols on Driving Ability in Adults with Chronic Tic Disorders: Results of a Substudy Analysis of the Double-Blind, Randomized, Placebo-Controlled CANNA-TICS Trial.." Cannabis and cannabinoid research, 2024. https://doi.org/10.1089/can.2023.0114

RethinkTHC

RethinkTHC Research Database. "The Effect of Nabiximols on Driving Ability in Adults with C..." RTHC-05574. Retrieved from https://rethinkthc.com/research/muller-vahl-2024-the-effect-of-nabiximols

Access the Original Study

Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.

This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.