Motor vehicle accidents are the leading cause of death among teenagers in the UK, accounting for 30% of male and 17% of female deaths. Statistically, teenage motorists are ten times more likely to be killed or seriously injured while driving than motorists in their 40s. According to the US National Highway Traffic Safety Administration and the National Center for Statistics and Analysis, in 2008, hand-held mobile phone use, impairment due to alcohol, speeding and failure to use a seatbelt were features in more than 80% of fatal crashes among 16- to 24-year-olds. Factors increasing the vulnerability of young drivers include inattention, impulsivity, immature judgement, thrill-seeking tendencies and impaired executive function skills. Attention deficit hyperactivity disorder (ADHD) is defined as a ‘persistent pattern of inattention and/or hyperactivity-impulsivity that is more frequently displayed and is more severe than is typically observed in individuals at a comparable level of development’.