The role of evaluative learning in the development and persistence of posttraumatic stress disorder

A minority of trauma-exposed individuals develops posttraumatic stress disorder
(PTSD), and for about half of them the disorder becomes chronic. The crucial
question is which abnormalities in the processing of trauma-related information
are involved in the development and persistence of PTSD symptoms. Much is known
about fear-related processes, but important aspects remain unclear. This
proposal includes several studies of the role of disgust and evaluative
learning in the onset/maintenance of PTSD symptoms. We will critically test the
proposed hypotheses with laboratory experiments in a sample of (1) people
recently exposed to burglary and (2) female assault victims with and without
PTSD.

To examine the role of fear and disgust in acute and chronic PTSD symptoms.

In study 1 we will investigate (1) whether the US-representation of burglary
involves danger and disgust-related elements that contribute independently to
PTSD symptoms and (2) whether disgust-related vulnerabilities are associated
with the degree of PTSD symptoms, after controlling for fear-related
vulnerabilities. It is hypothesized (I) that stronger implicit and explicit
associations between the concept *own house* and danger and *own house* and
repulsive predicts PTSD symptom severity, and (II) that the extent of the
concept *own house* being intrinsically aversive predicts PTSD symptom severity.

In study 2 we will investigate in female assault victims (1) whether danger and
disgust-associations independently predict residual PTSD-symptoms after
treatment, and (II) whether implicit and explicit fear and disgust associations
are stronger in individuals with PTSD as compared to individuals without PTSD.
It is hypothesized (I) that stronger implicit and explicit associations between
the concept *men* and danger and the concept *women* and no danger (vs. *men* +
no danger, *women* + danger) and the concept *men* and repulsive and the
concept *women* and not repulsive (vs. *men* + not repulsive and *women* +
repulsive), respectively, will differentiate assault victims with and without
PTSD, (II) that stronger self-repulsive associations will be related to
residual PTSD symptoms, (III) that implicit disgust associations predict
rinsing behavior, (IV) that explicit disgust associations predict
imagery-related disgust, and (V) that residual disgust associations after
treatment strongly predict post-treatment prognosis.

Study 1 is a longitudinal study among victims of burglary. Study 2 is a
case-control study of female victims of assault with and without PTSD, with an
observational part in which the PTSD group will be followed up after standard
treatment. The first test session for participants with PTSD will take place
before treatment.

The burden involves time and effort to complete questionnaires that assess
mood, thoughts, and PTSD symptoms, a brief interview about the burglary or
assault, and experimental paradigms that measure fear and disgust-related
variables. Study 1 includes one testing session of 2hrs15min at Utrecht
University, and one testing session of about 20 min at home (i.e., completing a
questionnaire). Study 2 includes two testing session for the PTSD group: (1)
before treatment (1hr35min) and (2) after treatment (30 min) at the mental
health care unit. For the healthy control group, Study 2 includes one testing
session (2hr) at Utrecht University. All measures have been used in prior
research. The questionnaires and interview may cause temporary distress.
Otherwise, there are no risks associated with these studies. All measures will
be administered by clinical psychologists. People will receive financial
compensation for their participation, but otherwise will not directly benefit.
We feel that the potential clinical applications of the results outweigh the
relatively mild burden associated with participation.