A clinical method of evaluating simple reaction time and reaction accuracy is sensitive to a single dose of lorazepam

J Psychopharmacol. 2020 Aug;34(8):920-925. doi: 10.1177/0269881120915409. Epub 2020 Jun 13.


Rationale: Benzodiazepines are useful and commonly prescribed. Unfortunately, they are associated with subtle but functionally significant neurocognitive side effects that increase the risk of motor vehicle accidents and falls.

Objective: The objective of this study was to determine whether clinically feasible measures of simple reaction time and reaction accuracy are sensitive to a single dose of lorazepam.

Methods: Using a randomized, double-blind, crossover design, 26 healthy adults (13 women; age = 26.9 ± 8.2 yr) were given 1.0 mg lorazepam or placebo 90 minutes prior to two data collection sessions. Participants completed simple and reaction accuracy tasks using a standardized "ruler drop" testing paradigm during each session. Outcomes were mean and variability of simple reaction time and reaction accuracy, which evaluates a participant's ability to catch the device solely on the random 50% of trials that lights affixed to it illuminate on release. Reaction accuracy requires a go/no-go decision within 420 ms before the falling device strikes the floor.

Results: As compared with placebo, lorazepam increased simple reaction time variability (range = 43 ± 18 vs. 60 ± 23 ms, respectively; p = 0.004 and standard deviation = 14.6 ± 5.7 vs. 19.7 ± 7.3 ms, respectively; = 0.006) and decreased reaction accuracy (90 ± 7% vs. 84 ± 11%, respectively; p = 0.010).

Conclusion: Given prior work demonstrating associations between simple reaction time and reaction accuracy and functional outcomes such as self-protection, response to perturbations, and fall risk, these clinically available measures may have a role in identifying subtle, functionally significant cognitive changes related to short-term benzodiazepine use.

Keywords: Benzodiazepines; clinical medicine; cognition; double blind method; reaction time.

Publication types

  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Cognitive Dysfunction / chemically induced*
  • Cross-Over Studies
  • Double-Blind Method
  • Female
  • Humans
  • Hypnotics and Sedatives / administration & dosage
  • Hypnotics and Sedatives / pharmacology*
  • Lorazepam / administration & dosage
  • Lorazepam / pharmacology*
  • Male
  • Psychomotor Performance / drug effects*
  • Reaction Time / drug effects*
  • Young Adult


  • Hypnotics and Sedatives
  • Lorazepam