2010 BC Guide in Determining Fitness to Drive

Schizophrenia (Axis I)Schizophrenia affects 1% of the population, with onset typically in early adulthood (late teens tomid-30s). Males and females are affected equally.Personality disorders (Axis II)In the United States, the prevalence of personality disorders is estimated to be between 6 and 9%.Suicidal ideationIn the general population of Canada, the estimated prevalence of suicidal ideation is from 5 to18%. The incidence of suicide attempts in the general population is from 1 to 5%.19.3 Psychiatric disorders and adverse driving outcomesDespite the prevalence of psychiatric disorders in the general population, there have been fewinvestigations into the relationship between these disorders and adverse driving outcomes.Surprisingly, the majority of research was done, on average, more than 30 years ago.There are a number of methodological issues that impact the ability to draw conclusions from theexisting research, in particular, the impact of improved treatment of psychiatric disorders andchanges in the complexity of the driving environment on the results of older studies.Nonetheless, the consistency of findings supports a general conclusion that drivers withpsychiatric conditions are at increased risk of adverse driving outcomes.Mood disorders - Major Depressive Disorder, Bipolar Disorder, DysthymicDisorderA few studies have identified depression as one of a number of factors that may influence drivingperformance. However, the results of these studies are equivocal, and methodologicallimitations significantly limit any conclusions that may be drawn.Pharmacological treatment of mood disorders is an important consideration. When treatment iseffective, the alertness, cognitive ability and judgment of a person with a mood disorder may beimproved. At the same time, the significant side effects of anti-depressant medications mayinclude impairments in psychomotor functioning, sedation, and impairments in cognitivefunctioning. The impact of the side effects of drug treatment on driving is considered in Chapter29, Psychotropic Drugs.Anxiety disordersThere are no studies that have investigated the relationship between anxiety disorders anddriving. Pharmacological treatment with sedatives or hypnotics may include side effects thatimpair functional ability to drive. See Chapter 29, Psychotropic Drugs, for more information.231