Review of Crash Risk and Driving
Performance for Drivers with
Mental and Personality Disorders
Dr. Nicholas J. Ward
HumanFIRST Program
University of Minnesota
The Houston Study
Sociopath Fatals were cases of drivers killed in a crash for
25 Alcoholic which they were responsible. Controls taken from
local voter lists from same precincts as fatalities.
22 Assumed that this matched for income level and
standard of housing . Matched on age and gender.
20 19 Attempted to match on race. Fatals were significantly
more likely to have personality disorders – notably
alcoholism and sociopathology.
15 Normal
Personality Disorder
10 Psychotic
5
5
2
1 1
0
Fatality (n = 25) Control (n = 25)
(adapted from Finch, 1970)
Interactions
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).
(see Rasanen, Hakko, & Jarvelin, 1999)
Sociopathology
US crash involvement and arrest
rates
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.
(Evans, 1991, p. 142)
Personality Types (see Deery & Fildes, 1999)
A B C D E
Assertiveness + -
Depression - ++ - +
Emotional - ++ - ++
Maladjustment Some combinations of personality traits and disorders
Internality can combine into risky profiles. Notably (E),
-
depression, and emotional maladjustment in
combination with a risk taking (sensation seeking)
Externality + -
can result in a risk driving style with a high crash
involvement in which the driver is culpable.
Sensation + - +
Seeking
Driving Style High Low Low Low Highest
(Risk)
Crash 3.7% 15.8% 2.0% 3.4% 19.0%
Involvement
Crash 3.7% 10.5% 2.0% 1.7% 9.5%
Culpability
Aggressive Driving
Premise: two-thirds of all crashes
result from “aggressive driving”
Aggressive drivers more likely than
controls to have:
Antisocial Personality Disorder
Borderline Personality Disorder
Intermittent Explosive Disorder
Substance Abuse
(Anxiety Disorder)
(see Galovski, Blanchard, & Veazey, 2002)
“Road Rage”
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)
(see Fong, Frost & Stansfeld, 2001)
Summary
Personality 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 Screening
Biased criteria
Gender, education
False positives
Restricted drivers no infractions/crashes
Misses
Crash 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
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 Non-Behavioral
disorders and intervening factors. Factors
Personality Pre-Crash Crash
Disorder State
Stressful
Alcohol
Events
(adapted from Finch, 1970)
Crash Etiology
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.
Personality Disorder Pre-crash State
Fatal (76%) Fatal (92%) Crash
(44%
Control (8%) Control (12%) 16%)
80%
72%
12%
Stressful Events Alcohol > 0 mg%
(adapted from Finch, 1970)
Crash Etiology
(see Sumer, 2003)
Treatments
Treat general disorder
Psychiatric counseling & medication
Drug side-effects
Treatment in driving context for specific
impairments
Hazard-perception, decision-making, and
attention-management skill training
Anger and aggression management
Motivating insurance programs
Need theory to justify screening (predict
risk) and guide treatments
Policy Issues
Screening or intervention based on
“predicted” risk by group membership
may not be cost-effective or ethical.
Better models of crash etiology
Validated 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.