title: Controlled-release methylphenidate improves attention during on-road driving by adolescents with attention-deficit/hyperactivity disorder.
abstract: BACKGROUND
  Attention-deficit/hyperactivity disorder (ADHD) is associated with a 3- to 4-fold increase in both driving-related accidents and associated injuries. Methylphenidate (MPH) is the most commonly prescribed psychostimulant medication for ADHD. It has been demonstrated to improve performance on a driving simulator. This study investigated whether a once-daily, long-acting, osmotic, controlled-release MPH formulation improves the driving performance of ADHD adolescents while driving their own car on an actual road segment.
  
  
  METHODS
  Twelve ADHD-diagnosed male adolescent drivers (mean age, 17.8 years) prescribed a standard dose of 1.0 mg/kg (if they were not already taking methylphenidate) of controlled-release MPH participated in this repeated-measures crossover study. On 2 separate occasions (off/on medication randomized), participants drove a standard 16-mile road course incorporating rural, highway, and urban streets. A rater, blind to medication conditions, sat in the back seat and rated impulsive (eg, "cutting off" another driver) and inattentive (eg, drove past designated turn) driving errors.
  
  
  RESULTS
  Impulsive driving errors were observed to occur rarely under both medication and no medication conditions. Inattentive driving errors were more common and were significantly reduced while the subject was on medication (4.6 versus 7.8; P <.01). The improvement in driving performance (change in number of errors recorded) from first to second testing was positively correlated with medication dosage (r = 0.60; P <.01).
  
  
  CONCLUSIONS
  Once-daily controlled-release MPH improves real-life driving performance of adolescent males diagnosed with ADHD. In particular, it significantly reduces driving errors arising from inattention.
authors.affiliation: University of Virginia, Department of Psychiatric Medicine, Charlottesville, 22908, USA. djc4f@virginia.edu
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Cox
authors.forename: Jeffery W
authors.initials: JW
authors.lastname: Humphrey
authors.forename: R Lawrence
authors.initials: RL
authors.lastname: Merkel
authors.forename: Jennifer Kim
authors.initials: JK
authors.lastname: Penberthy
authors.forename: Boris
authors.initials: B
authors.lastname: Kovatchev
mesh_terms: D000293:Adolescent; D001288:Attention / Q000187:drug effects*; D001289:Attention Deficit Disorder with Hyperactivity / Q000188:drug therapy* / Q000503:physiopathology; D001334:Automobile Driving / Q000523:psychology* / Q000592:standards; D000697:Central Nervous System Stimulants / Q000627:therapeutic use*; D004334:Drug Administration Schedule; D006801:Humans; D007175:Impulsive Behavior / Q000188:drug therapy; D008297:Male; D008774:Methylphenidate / Q000627:therapeutic use*; D016896:Treatment Outcome
chemical_list: D000697:Central Nervous System Stimulants; D008774:Methylphenidate