Review of Crash Risk and Driving Performance for Drivers with Mental and Personality Disorders

Dr. Nicholas J. WardHumanFIRST Program

University of Minnesota

The Houston Study

5

22

19

21 1

0

5

10

15

20

25

Fatality (n = 25) Control (n = 25)

NormalPersonality DisorderPsychotic

(adapted from Finch, 1970)

Sociopath

AlcoholicFatals were cases of drivers killed in a crash for which they were responsible. Controls taken from local voter lists from same precincts as fatalities. Assumed that this matched for income level and standard of housing . Matched on age and gender. Attempted to match on race. Fatals were significantly more likely to have personality disorders – notably alcoholism and sociopathology.

Interactions

(see Rasanen, Hakko, & Jarvelin, 1999)

Alcoholism can interact with other factors. In this case, a birth cohort in Finland were examined in terms of history of violent crime and mental disorders in terms of convictions for drunk driving. The combination of violent tendencies with a mental disorders had the highest propensity for alcohol consumption with driving (DWI).

SociopathologyUS crash involvement and arrest

rates

(Evans, 1991, p. 142)

There is a compelling similarity in the shape of the age distribution of both traffic crash involvement and criminal arrests. Curiously, this may suggest that some forms of sociopathology that are related to criminal dispositions may also relate to driving behaviors and attitudes that can result in a crash.

Personality TypesA B C D E

Assertiveness + -

Depression - ++ - +

Emotional Maladjustment

- ++ - ++

Internality -

Externality + -

Sensation Seeking

+ - +

Driving Style (Risk)

High Low Low Low Highest

Crash Involvement

3.7% 15.8% 2.0% 3.4% 19.0%

Crash Culpability

3.7% 10.5% 2.0% 1.7% 9.5%

(see Deery & Fildes, 1999)

Some combinations of personality traits and disorders can combine into risky profiles. Notably (E), depression, and emotional maladjustment in combination with a risk taking (sensation seeking) can result in a risk driving style with a high crash involvement in which the driver is culpable.

Aggressive DrivingPremise: two-thirds of all crashes result from “aggressive driving”Aggressive drivers more likely than controls to have:

Antisocial Personality DisorderBorderline Personality DisorderIntermittent Explosive DisorderSubstance Abuse(Anxiety Disorder)

(see Galovski, Blanchard, & Veazey, 2002)

“Road Rage”

(see Fong, Frost & Stansfeld, 2001)

This table shows measures of psychological disorders and aggressive traits for a group of drivers that reported that they had perpetrated a road rage event, were victims of a road rage event, or were never involved in a road rage event (controls). “Lower levels of psychological/psychiatric distress may protect from involvement in road rage incidents as perpetrators or victims, while lower levels of aggression may protect people from being perpetrators.” (p. 285)

SummaryPersonality disorders are related to crash risk and risky behaviors.

There are interactions amongst risk factors:

Impulsive anger, aggression

Indifference to social norms

Risk taking style

Substance abuse

Medical ScreeningBiased criteria

Gender, education

False positivesRestricted drivers no infractions/crashes

MissesCrash involved drivers with disorders

It remains to supply psychiatrists and general practitioners with new information, which is quantitatively as well as qualitatively valid, on the real nature and role of mental disorders in automobile crashes and traffic violations.

(Niveau & Kelly-Puskas, 2001)

Crash Etiology

Personality Disorder

Pre-Crash State

Crash

Stressful Events

Alcohol

Non-Behavioral Factors

(adapted from Finch, 1970)

In order to identify risk factors and develop valid assessment tools, it is necessary to describe (and predict) the etiology of crashes related to personality disorders and intervening factors.

Crash Etiology

Fatal (76%)Control (8%)

Fatal (92%)Control (12%)

Crash(44%16%)

80%12%

72%

(adapted from Finch, 1970)

Personality Disorder

Stressful Events Alcohol > 0 mg%

Pre-crash State

Note that 44% of fatals had prior crash whereas only 16% of controls had prior crash. Similarly, 60% of fatals had four or more traffic convictions compared to 8% of controls.

Crash Etiology

(see Sumer, 2003)

TreatmentsTreat general disorder

Psychiatric counseling & medicationDrug side-effects

Treatment in driving context for specific impairments

Hazard-perception, decision-making, and attention-management skill trainingAnger and aggression management

Motivating insurance programsNeed theory to justify screening (predict risk) and guide treatments

Policy IssuesScreening or intervention based on “predicted” risk by group membership may not be cost-effective or ethical.

Better models of crash etiologyValidated treatments

Drunk-driving offenders need assessment and treatment for alcohol problems AND possibility of other psychiatric disorders.Psychiatric examination of aggressive drivers may support treatment of this group AND co-morbid problems.