Exposure therapy explored
for treatment of driving phobias
BY KRISTIN WEIDENBACH
Cruising in a convertible
across the Golden Gate Bridge is a scene made famous in
the movie "Interview with the Vampire," and for
many visitors it embodies California's automobile-centric
lifestyle. But for people with a driving phobia, merging
onto a freeway filled with fast-moving traffic can induce
an anxiety attack and confronting a bridge can be their
worst nightmare.
Marcia Feitel was one of
those people. A 44-year-old software engineer, she was
terrified at the prospect of driving faster than 40 miles
per hour and so avoided freeways at all cost. "I
didn't learn to drive until I was 28, so when I finally
did learn there was a lot of anxiety associated with
going fast," Feitel said. She was also upset by
roads that bank as they round a corner and by tire skid
marks on the road which reinforced her belief that the
streets are rife with dangerous drivers. "When I saw
the road was banked, it was very stressful not to slow
down," Feitel said. "And I was not happy to see
skid marks on the road. Those were things that triggered
a burst of fear in me."
So Feitel enrolled in a
Stanford study designed to monitor the emotions and
bodily reactions of people who are afraid to drive. The
study is designed to gauge the effectiveness of exposure
therapy as a means to treat the condition. Exposure
therapy involves entering the avoided situation and
confronting the anxiety, and commonly is used to treat
phobias such as fear of spiders or flying in an airplane.
"The study is
designed to overcome the phobia of driving a car,"
said Georg Alpers, psychologist and visiting researcher
in the department of psychiatry and behavioral sciences.
Alpers is conducting the study with research associate
Frank Wilhelm, PhD, and Walton Roth, MD, professor of
psychiatry and behavioral sciences and Chief of the
Psychiatric Consultation Service at the Veteran's Affairs
Palo Alto Health Care System.
Study participants agree
to several treatment sessions whereby they drive in a
variety of typical situations. The route is designed
specifically for each patient, who typically spends 60 to
90 minutes on the road in each of the three sessions.
Each trip focuses on one previously avoided driving
situation.
For her first session,
Feitel was asked to drive onto Highway 101. "I was
almost sick with fear," she said. "I was never
aware that it's possible to get that frightened. It was
all I could do to drive back to work afterwards." By
the third session, she was able to move to the fast lane
and overtake another vehicle. "That was viewed as
progress," she said.
Before the trip, the
driver is outfitted with an array of sensors that monitor
heart rate, breathing and skin conductance, the last of
which gives the researcher an indication of how much the
subject is sweating. Information is collected
continuously and captured via a portable recorder
attached to the waist. The person's saliva is sampled at
various times to detect any changes in the level of
stress hormones, and the gas mixture of the air the
person exhales is also monitored. These physical
measurements are then correlated with the person's
subjective reports of the level of anxiety experienced
throughout the drive. The researcher then compiles the
physical and psychological data to reach an overall
assessment of the anxiety level experienced by each
patient.
"We monitor the
physiology in the lab and during the driving," said
Alpers. The data collected from each anxious subject is
compared to the same data collected from age- and
gender-matched control subjects.
According to Alpers, fear
of driving is especially suited to physiological
evaluation in real life situations because, unlike many
agoraphobic situations e.g. walking in crowded places,
driving entails only minimal exercise. The relative lack
of physical activity necessary to drive a car means that
any changes in heart and respiration rates reflect the
patient's response to the anxiety-provoking situation
rather than changes induced by exercise. To calculate a
base-line level for each patient, measurements of all
parameters also are made when the person is at rest and
when they are exercising on a stationary bicycle.
Preliminary results from
the first twenty-one patients, who are all women, show
that heart rate and the subjective anxiety rating were
lower on the inbound, or return, leg of the journey than
on the outbound leg. Both values also decreased over the
three sessions suggesting that patients felt less anxious
after completion of the study.
Measurements for
individual patients found that the level of exhaled
carbon dioxide decreased and the heart rate increased
when the driver confronted an anxiety-provoking
situation, such as crossing a bridge. These preliminary
results have led Alpers to conclude that subjects with a
driving phobia subconsciously over-prepare for emergency
physical activity their body reacts by inhaling more
oxygen and exhaling more carbon dioxide than they
currently need, which is defined as hyperventilation. For
some people, the sensations resulting from
hyperventilation make them feel even more anxious.
Feitel says that the
exposure itself is empowering. "The fact that you're
doing something is positive reinforcement," she
said. "A lot of my fear had to do with doing the
wrong thing and causing injury to myself or others. The
study got me believing that I could make some improvement
in how I felt I went from being ready to collapse, to
just being kind of edgy. And once I actually got onto the
highway, the other things that I was afraid of just
didn't happen."
Alpers is still recruiting
volunteers for the study. Control subjects are paid $15
per hour for each 4-hour driving session. For further
information, call (650) 493-5000 extension 65640. SR
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