Effects of valerian on subjective sedation, field sobriety testing and driving simulator performance

• Valerian demonstrates no impairment by field sobriety testing.
• Valerian demonstrates no impairment by driving simulator performance parameters.
• Valerian demonstrates equivalence to placebo on driving simulator parameters.

IntroductionThe availability of herbal medicines over-the-counter (OTC) has increased the use of natural products for self-treatment. Valerian has been used to effectively treat generalized anxiety disorder and insomnia. Studies suggest that valerenic acid may increase gamma-aminobutyric acid (GABA) modulation in the brain. Benzodiazepines have a similar mechanism of action and have been linked to an increased risk of hospitalizations due to traffic accidents. Despite the risk of somnolence, the safety of driving while under the influence of valerian remains unknown.PurposeThe purpose of the study was to determine the effects of a one-time valerian 1600 mg dose on subjective sedation effects, standardized field sobriety testing (SFST) and driving simulator performance parameters.MethodsThe study design was a randomized, placebo-controlled, double-blind, cross-over trial. For each session, participants received either a dose of valerian or placebo. The outcome measures included a simple visual reaction test (SVRT), subjective sleepiness scales, SFST performance scores, and driving simulator performance parameters.ResultsThere were no significant differences in the SVRT or sleepiness scales between placebo and valerian exposures, but the study may have been underpowered. SFST total and individual test failure rates were not significantly different between the two exposures. The driving simulator performance parameters were equivalent between the two exposure conditions.ConclusionsA one-time valerian 1600 mg dose, often used to treat insomnia, does not appear to impair driving simulator performance after acute ingestion.