title: Driving behaviour in adults with attention deficit/hyperactivity disorder.
abstract: BACKGROUND
  Little is known about the impact of cognitive impairments on driving in adults with ADHD. The present study compared the performance of adults with and without ADHD in a driving simulator on two different routes: an urban route which we hypothesised would exacerbate weak impulse control in ADHD and a motorway route, to challenge deficits in sustained attention.
  
  
  METHODS
  Adults with (n = 22, 16 males) and without (n = 21, 18 males) ADHD completed a simulated driving session while eye movement data were recorded simultaneously. Participants also completed the Manchester Driving Behaviour Questionnaire (DBQ) and the Conners Adult ADHD Rating Scale (CAARS). Measures of driving performance included average speed, proportion distance travelled over speed limit (speeding) and lane deviation. These variables and the eye movement measures (spread of fixations, mean fixation duration) were compared between groups and routes. Also, driving behaviours, including responses to programmed events, were categorised and the frequencies within categories were compared between groups. Finally, speech analysis was performed to compare emotional verbal expressions during driving between groups.
  
  
  RESULTS
  ADHD participants reported significantly more Violations and Lapses on the DBQ than control participants and significantly more accidents. Average speed and speeding were also higher but did not interact with route type. ADHD participants showed poorer vehicle control, greater levels of frustration with other road users (including greater frequencies of negative comments) and a trend for less safe driving when changing lanes/overtaking on the motorway. These effects were predicted by hyperactive/impulsive CAARS scores. They were also more likely to cause a crash/near miss when an event occurred on the urban route.
  
  
  CONCLUSIONS
  The results suggest that difficulty regulating and controlling impulsive behavior, reflected in speeding, frustration with other road users, less safety when changing lanes on the motorway and a greater likelihood of an accident following an unexpected event, underlie impaired driving in ADHD. Hyperactivity/impulsivity symptoms correlated with these indices. Deficits in sustained attention seemed to play a lesser role in this particular study, although further research is needed to determine whether effects on attention emerge over longer periods of time and/or are influenced by the novelty of the simulator environment.
authors.affiliation: Division of Psychiatry and Applied Psychology, University of Nottingham, Institute of Mental Health, University Of Nottingham Innovation Park, Triumph Road, Nottingham, NG7 2TU, UK. maddie.groom@nottingham.ac.uk.
authors.forename: Madeleine J
authors.initials: MJ
authors.lastname: Groom
authors.affiliation: Division of Psychiatry and Applied Psychology, University of Nottingham, Institute of Mental Health, University Of Nottingham Innovation Park, Triumph Road, Nottingham, NG7 2TU, UK.
authors.forename: Editha
authors.initials: E
authors.lastname: van Loon
authors.affiliation: Division of Psychiatry and Applied Psychology, University of Nottingham, Institute of Mental Health, University Of Nottingham Innovation Park, Triumph Road, Nottingham, NG7 2TU, UK.
authors.forename: David
authors.initials: D
authors.lastname: Daley
authors.affiliation: School of Psychology, University Of Nottingham, University Park, Nottingham, NG7 2RD, UK.
authors.forename: Peter
authors.initials: P
authors.lastname: Chapman
authors.affiliation: Division of Psychiatry and Applied Psychology, University of Nottingham, Institute of Mental Health, University Of Nottingham Innovation Park, Triumph Road, Nottingham, NG7 2TU, UK.|Department of Child and Adolescent Psychiatry, Nottinghamshire Healthcare NHS Trust, E Floor, South Block, Queens Medical Centre, Derby Road, Nottingham, NG7 2UH, UK.
authors.forename: Chris
authors.initials: C
authors.lastname: Hollis
mesh_terms: D000293:Adolescent; D000328:Adult; D001288:Attention / Q000502:physiology; D001289:Attention Deficit Disorder with Hyperactivity / Q000523:psychology*; D001334:Automobile Driving; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D006948:Hyperkinesis / Q000523:psychology; D007175:Impulsive Behavior; D008297:Male; D008875:Middle Aged; D012449:Safety; D011795:Surveys and Questionnaires; D055815:Young Adult