title: Acute stimulant ingestion and neurocognitive performance in healthy participants.
abstract: BACKGROUND
  Concussion management has become an area of great concern in athletics, and neurocognitive tests, such as Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT), are commonly used as management tools. Given the restrictive nature of current management plans, anecdotal concerns have been raised about athletes trying to cheat the assessments and return to participation sooner. Stimulants have been shown to improve neurocognitive measures similar to those used in ImPACT. Therefore, they could possibly improve performance during baseline and postinjury testing.
  
  
  OBJECTIVE
  To examine the effects of a supplement containing stimulants on ImPACT performance.
  
  
  METHODS
  Crossover study.
  
  
  METHODS
  Research laboratory.
  
  
  METHODS
  A total of 5 men (age = 20.6 ± 1.5 years, height = 176.3 ± 9.6 cm, mass = 76.9 ± 18.6 kg) and 7 women (age = 20.6 ± 1.1 years, height = 162.9 ± 7.8 cm, mass = 60.9 ± 8.2 kg) with no histories of physician-diagnosed head injury, learning disability, or attention-deficit disorder.
  
  
  METHODS
  Participants were assessed under supplement (5.5 g of Jacked 3D, which contains caffeine and 1,3-dimethylamylamine), placebo, and control conditions separated by 1 week.
  
  
  METHODS
  I compared ImPACT composite scores for verbal and visual memory, visual motor speed, reaction time, impulse control, and a cognitive-efficiency index under each of the 3 conditions and assessed them 30 minutes after ingestion.
  
  
  RESULTS
  I observed a difference when comparing reaction times, as the participants reacted faster during the supplement condition (0.53 ± 0.03 seconds) than during the placebo (0.55 ± 0.03 seconds) and control (0.55 ± 0.03 seconds) conditions (F2,22 = 4.31, P = .03). A difference also was observed for the cognitive-efficiency index, as participants scored higher during the supplement condition (0.49 ± 0.09) than during the placebo (0.41 ± 0.10) and control (0.41 ± 0.12) conditions (F2,22 = 4.07, P = .03).
  
  
  CONCLUSIONS
  Stimulant ingestion 30 minutes before testing resulted in improved memory, visual processing speed, and reaction time. However, the improvements were relatively nominal, and the question of clinical importance remains. Thus, it is unclear if stimulant ingestion would affect the return-to-participation progression.
authors: Marist College, Poughkeepsie, NY.
authors: Michael E
authors: ME
authors: Powers
mesh_terms: D000588:Amines / Q000494:pharmacology*; D001265:Athletic Injuries / Q000150:complications / Q000175:diagnosis / Q000523:psychology; D001924:Brain Concussion / Q000175:diagnosis* / Q000209:etiology; D002110:Caffeine / Q000494:pharmacology*; D000697:Central Nervous System Stimulants / Q000494:pharmacology; D018592:Cross-Over Studies; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D008568:Memory / Q000187:drug effects; D009483:Neuropsychological Tests; D058573:Performance-Enhancing Substances / Q000494:pharmacology; D011597:Psychomotor Performance / Q000187:drug effects*; D011930:Reaction Time / Q000187:drug effects; D055815:Young Adult
chemical_list: C571979:1,3-dimethylamylamine; D000588:Amines; D000697:Central Nervous System Stimulants; D058573:Performance-Enhancing Substances; D002110:Caffeine
keywords: 1,3-dimethylamylamine; ImPACT; caffeine; processing speed; reaction time