Conversion disorder is a psychiatric condition in which psychological stress manifests as some physical dysfunction. For example, stress associated with divorce proceedings might result in development of headaches, dermatological problems, breathing difficulties, and the like. In extreme cases, conversion disorder can result in abnormal movements, paralysis, or non-epileptic seizures. Poole, Wuerz and Agrawal (2010) recently reported that conversion disorder most frequently occurs in women, with a mean age of onset of approximately 29 years. One interesting feature of conversion disorder is that, in some cases, the effects of one individual can induce stress in other individuals, resulting in symptom manifestation in numerous people within an intimate population such as a school, workplace, or military squad (For review see: Bartholomew & Sirois, 2000). The phenomenon of multiple related cases of conversion disorder, once referred to as epidemic hysteria, is more commonly now referred to as mass psychogenic illness (MPI). A variety of treatments for conversion disorder have been reported ranging from hypnosis (Moene, Spinhoven, Hoogduin & van Dyck, 2002) to drug therapy (Stevens, 1990). Moene and colleagues (2002) note that behavior therapy with operant conditioning may be successful in reducing symptoms in conversion disorder patients. It is reasonable to assume that such behavior therapy could be effectively administered in a group of patients. Furthermore, given the nature of social cue influences on this disorder, as seen with MPI, successful treatment of one or more individuals in a group setting could have residual positive effects on others within the group. It is well established that positive behaviors can be shaped through modeling in a therapeutic setting. Researchers have shown, for example, that phobic behaviors can be reduced when one phobic individual watches another phobic individual (or a confederate acting as a phobic individual) calmly engaging in the fear provoking behavior (e.g. Geer & Turteltaub, 1967). Furthermore, it is possible for a single individual to evoke modeling behavior among a group, particularly when the behavior being exhibited is viewed positively by the members of that group (Peterson, Kaasa & Loftus, 2008). With all of this information considered, the present study was designed to determine if individuals exhibiting effects of MPI would respond positively to behavior therapy in a group setting. It was further hypothesized that using a confederate, acting as a patient within the group, could enhance positive effects of therapy if that confederate reported positive influences of the therapy that could then be modeled by other members of the group. To test this hypothesis, a group of women, all diagnosed with chronic conversion disorder manifesting in abnormal movements and facial tics, were assigned to one of three groups. The first group received behavior therapy in a group setting that.

1. Conversion disorder is a psychiatric condition in which
psychological stress manifests as some physical dysfunction.
For example, stress associated with divorce proceedings might
result in development of headaches, dermatological problems,
breathing difficulties, and the like. In extreme cases,
conversion disorder can result in abnormal movements,
paralysis, or non-epileptic seizures. Poole, Wuerz and Agrawal
(2010) recently reported that conversion disorder most
frequently occurs in women, with a mean age of onset of
approximately 29 years. One interesting feature of conversion
disorder is that, in some cases, the effects of one individual can
induce stress in other individuals, resulting in symptom
manifestation in numerous people within an intimate population
such as a school, workplace, or military squad (For review see:
Bartholomew & Sirois, 2000). The phenomenon of multiple
related cases of conversion disorder, once referred to as
epidemic hysteria, is more commonly now referred to as mass
psychogenic illness (MPI).
A variety of treatments for conversion disorder have been
reported ranging from hypnosis (Moene, Spinhoven, Hoogduin
& van Dyck, 2002) to drug therapy (Stevens, 1990). Moene and
colleagues (2002) note that behavior therapy with operant
conditioning may be successful in reducing symptoms in
conversion disorder patients. It is reasonable to assume that
such behavior therapy could be effectively administered in a
group of patients. Furthermore, given the nature of social cue
influences on this disorder, as seen with MPI, successful
treatment of one or more individuals in a group setting could
have residual positive effects on others within the group.
It is well established that positive behaviors can be shaped
through modeling in a therapeutic setting. Researchers have
shown, for example, that phobic behaviors can be reduced when
one phobic individual watches another phobic individual (or a
confederate acting as a phobic individual) calmly engaging in

2. the fear provoking behavior (e.g. Geer & Turteltaub, 1967).
Furthermore, it is possible for a single individual to evoke
modeling behavior among a group, particularly when the
behavior being exhibited is viewed positively by the members
of that group (Peterson, Kaasa & Loftus, 2008).
With all of this information considered, the present study was
designed to determine if individuals exhibiting effects of MPI
would respond positively to behavior therapy in a group setting.
It was further hypothesized that using a confederate, acting as a
patient within the group, could enhance positive effects of
therapy if that confederate reported positive influences of the
therapy that could then be modeled by other members of the
group. To test this hypothesis, a group of women, all diagnosed
with chronic conversion disorder manifesting in abnormal
movements and facial tics, were assigned to one of three
groups. The first group received behavior therapy in a group
setting that included a confederate actor who appeared to show
significant improvement over a 3 week period. The second
group received behavior therapy in a group setting that included
a confederate actor who appeared to show improvement
consistent with the other group members over a 3 week period.
The third group acted as a control group, and received no
treatment. Success of the treatment was determined by
comparing posttest scores of tic frequency to pretest scores.
Patients were also surveyed to measure their subjective sense of
well-being following the completion of the study.
Method
Participants
Twenty one females ranging in age from 18 to 32 (mean age =
27.8) were referred by psychologists in the western New York
state region. All participants had received a clinical diagnosis

3. of conversion disorder, with symptoms manifesting as facial tics
and abnormal limb movements. All participants had been
diagnosed within the previous 12 months, with the most recent
diagnosis being 2 months prior to the study (mean time of
diagnosis = 7.1 months prior to study). None of the participants
reported taking any prescription medication to treat their
symptoms when interviewed for the present study.
Apparatus
A wearable device with an embedded three-axial
accelerometer as described by Bernabei and colleagues
(Bernabei, Preatoni, Mendez, Piccini, Porta M & Andreoni,
2010) was used to measure frequency and amplitude of tics.
Procedure
All participants were assessed for baseline tic severity
during a two week period prior to the beginning of the
experiment. Baseline data were collected over a 60 minute
period in the research laboratory where participants were
affixed with the accelerometer device and then asked to view
television programming of their choice while relaxed in a chair.
Baseline data were collected three times each week (Mon, Wed,
Fri, or Tue, Thu, Sat) between 12:00 and 17:00. A mean
baseline score was generated for each participant from the six
data points collected.
After the baseline data collection period, participants were
randomly assigned to one of three groups. Participants assigned
to the confederate accelerated recovery (CAR) group (n=7) and
the confederate normal recovery (CNR) group (n=7), met as
separate groups for one hour per day, for two days each week
(Mon & Wed), over a period of 4 months. Group therapy
sessions followed standard cognitive behavior therapy
procedures for treating anxiety related disorders (see
O'Donohue & Fisher 2008, for a review of basic methods).
Both groups were treated by the same therapist who was
clinically trained and licensed to administer this form of
treatment. Both groups also included a research assistant acting
as a confederate and posing as a conversion disorder patient.

4. The research assistant was trained in mimicking tic movements,
and was instructed to initially display such movements at a rate
equal to the mean baseline frequency for the group in which
they were participating.
For the CAR group, the research assistant showed progressive
improvement (a reduction in tic frequency) at a rate of 10%
reduction from the previous week, for each week of the study,
culminating in a total decrease of 80% from baseline at the
conclusion of the experimental period. In this treatment
condition, the research assistant also made one comment to the
group each week indicating a sense of symptom reduction.
For the CNR group, the research assistant showed progressive
improvement approximately equal to the improvement of the
group, as determined by visual observations made by the
research assistant and the therapist. In this treatment condition,
the research assistant made no comments regarding a change in
symptoms.
The remaining participants (n=7) acted as wait-list controls.
This group received no formal treatment for the duration of the
experiment.
The week following the conclusion of the four month
experimental period, all participants were tested three times in a
manner similar to that used for baseline data collection. In
addition, participants were asked to respond to a 7 point Likert-
type question regarding how much they felt their symptoms had
improved over the 4 month experimental period with a score of
1 indicating “not at all” and a score of 7 indicating “complete
remission”.