2010 BC Guide in Determining Fitness to Drive

Attention-Deficit/Hyperactivity Disorder (Axis I)There is a small body of research that suggests that drivers with ADHD are at a higher risk forcrashes, have higher rates of traffic citations, licence revocations or suspensions, and are morelikely to drive without a licence.There is some indication that pharmacological treatment of ADHD with stimulants may have apositive effect on driving performance. However, research in this area has primarily relied ondriving simulators to measure outcomes. A few studies have investigated the relationshipbetween pharmacological treatment of ADHD and on-road performance. However,methodological limitations, including small sample size (< 20 in all cases), limit the findings.The effects of pharmacological treatment of ADHD are discussed further in Chapter 29,Psychotropic Drugs.SchizophreniaThe results of the few studies on the relationship between Schizophrenia and adverse drivingoutcomes are equivocal. Given the functional impairments often associated with this disorder,the results are surprising. An important factor which may contribute to the equivocal results isdriver licensing rates. A recent study found that only 52% of individuals with Schizophreniawere licensed to drive compared to 96% in the control group. Failure to control for the reduceddriving exposure of individuals with Schizophrenia is an important consideration in that crashrates are likely an underestimation of impairments in driving performance in this population.Personality disordersTwo studies, both more than 30 years old, considered the relationship between personalitydisorders and adverse driving outcomes. Both studies found an increased crash risk forindividuals with personality disorders.Suicidal ideationStudies on the incidence of traffic suicides indicate that suicide attempts play a significant role inmotor vehicle crashes. Moreover, it is likely that the reported incidence rates of traffic suicidesare an underestimation, due to the methodological difficulties in classifying a traffic death assuicide.Research indicates the following risk factors for traffic suicides: males are significantly more at risk (90 to 95%) than females whites are more at risk than other racial groups those who are “depressed” or “mentally disturbed” are more at risk than those who are not,and those with a history of attempted suicide or a family history of suicide are more at risk thanthose without such history.232