ADHD Driving DR Emad Farrag MBBCh MRCPsych Consultant

ADHD & Driving DR Emad Farrag MBBCh, MRCPsych Consultant Child & Adolescent PSychiatrist

A bit of humour

My favourite Quote • ADHD, driving and texting; A deadly combination

A Car Story

Unintentional Injury • Growing global concern • In 2000, approx. 5 million died worldwide due to injuries • 2/3 were unintentional, most were due to RTAs • 50 million worldwide injured in RTAs • Leading cause of death in Children, adolescents & young adults in affluent countries • Recent figures show approx. 6 million RTAs in USA above 40 million deaths + 3 million injuries • It was estimated in 2004 alone US economy cost in excess of $200 billion

Other costs to consider • Personal mental health trauma • Physical mortality and disability • Economic rehabilitation of injured or disabled • Days off work • Loss of driving licence • Possible custodial sentence

DVLA & ADHD • You may need to tell DVLA if you have attention deficit/hyperactivity disorder (ADHD). • You can be fined up to £ 1, 000 if you don’t tell DVLA about a medical condition that affects your driving. You may be prosecuted if you’re involved in an accident as a result.

‘Accident proneness’ A man drives as he lives (Tillman & Hobbes 1949)

Personal Attributes other than ADHD • Being male • Anger management problems • Drug and alcohol use and abuse • Antisocial tendencies • Risk taking behaviour • Non conformity • Occupation & educational status inversely proportionate to RTAs

Theories Psychosocial theory Problem behaviour theory • Model of high risk driving related to states of high stress • Emphasis on lifestyle factors • Reduced parental involvement • Negative parental or peer influence • related to risky driving and negative driving outcomes

Cognitive abilities • Inattention and distractibility (1/4 of RTAs) • Poor risk perception • Reduced judgement & reasoning while driving • Normal brain maturational immaturities in the young (areas of the brain responsible for executive function + Inexperience driving Contribute to increased risky driving behaviours

Do studies show a relationship? • Yes but data differs and controlling for variables change the strength of the relationship; but there is an established relationship • Some use ADHD status (severity) alone • Others used categorical diagnosis (more here) • Using both showed even higher rates

Observational Studies • Significantly increased driving citations in ADHD vs. control group • Speeding, suspensions, driving without licence, tail gaiting • Increased citations for those with comorbid ODD/CD in males • In one study looked at ADHD & age vs. effect on driving (Driving Behaviour Questionnaire): • >40 years old Normalised error scores • >30 years old Normalised violation scores • Better driving with experience OR better avoidance of detection?

Simulator Studies • Increase scrapes • Increased steering variability • Poor steering control • may reflect poor motor control and coordination

Cognitive abilities related to driving • Inattentiveness (especially visual) late response counter measures • Impulsiveness speeding & inability to disengage from risky manoeuvres • Slow processing • Distractibility • Problem with visual memory

Treatment effect? IR-MPH • Wears off and has implications for night drivers • Better response inhibition and improving visual memory than dexamphetamine XL-MPH • Longer availability (advantage)

How does it help? • Treatment mediates the improved driving by: • Improving executive functioning • Particularly tasks of complex attention • Response inhibition

What next? • Do we screen for risky behaviours? Implications? • Reporting ADHD drivers deemed to be at risk of problem driving? • No law to say ADHD sufferers must take medication? Would that be discriminatory? • Is there a role for motivational interviewing (modify change especially around compliance? ) • Issue of drug driving and stimulant treatment? • Road safety is a public health problem so do we need a public health approach?

Thank you for listening & Drive safely