Carlos Sierra FIN-The effects of a treatment based on the use of virtual reality exposure and cognitive-behavioral therapy applied to patients with agoraphobia

© International Journal of Clinical and Health Psychology
ISSN 1697-2600
2008, Vol. 8, Nº 1, pp. 5-22
The effects of a treatment based on the use of
virtual reality exposure and cognitive-behavioral
therapy applied to patients with agoraphobia1
Wenceslao Peñate2 (Universidad de La Laguna, España),
Carmen T. Pitti (Hospital Universitario de Canarias, España),
Juan Manuel Bethencourt (Universidad de La Laguna, España),
Juan de la Fuente (Hospital Universitario Nuestra Señora de la Candelaria,
España), and Ramón Gracia (Hospital Universitario de Canarias, España)
(Received October 31, 2006 / Recibido 31 de octubre 2006)
(Accepted June 1, 2007 / Aceptado 1 de junio 2007)
ABSTRACT. Exposure to virtual reality phobic environments was used with patients
with chronic agoraphobia. The exposure to virtual stimuli has been verified as a useful
procedure in treating phobic disorders. However, there are some specific problems with
agoraphobia (determining phobic stimuli, avatars, etc.). The aim of this experimental
study is to test a combined treatment, virtual reality exposure and cognitive-behavioral
treatment (VRET), compared with a traditional cognitive-behavioral approach (CBT),
in reducing agoraphobia symptoms. Two experimental groups were used. 15 patients
with chronic agoraphobia received a VRET procedure (3D), and 13 received CBT. Both
groups had 11 treatment sessions. The post-treatment measurements included a brief
behavioral avoidance test (BAT). Results showed a significant improvement in agoraphobia
symptoms (cognition, body sensation, level of anxiety, depression) in both groups. In
general, this improvement remained three months later. Also, the BAT procedure indicated
the ability of most patients to deal with a phobic environment. Additionally, the VRET
1
This study was supported by grant PROFIT-150500-2003-131(former Department of Science and Technology,
Government of Spain), and grant PI 4/99 (FUNCIS, Autonomous Government of Canary Island). We wish
to thank Ms. Margaret Gillon Dowens for her technical corrections in the English translation of this paper.
2
Correspondence: Universidad de La Laguna. Facultad de Psicología. Departamento Personalidad, Evalua-
ción y Tratamientos Psicológicos. Campus de Guajara. 38204 La Laguna. Tenerife (España). E-mail:
wpenate@ull.es

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PEÑATE et al. Virtual reality exposure and cognitive-behavioral therapy in agoraphobia
group showed a slight amelioration of symptoms compared with the CBT group. These
data are discussed in terms of the specific difficulties of VRET with agoraphobia, and
the viability of our seven virtual environments to generate an acceptable exposure to
phobic stimuli.
KEY WORDS. Virtual reality. Cognitive-behavioral treatment. Agoraphobia. Experi-
mental study.
RESUMEN. La exposición a estímulos virtuales se ha verificado como un procedi-
miento útil en el tratamiento de los trastornos fóbicos. Sin embargo, existe una serie
de problemas en la aplicación a la agorafobia (estímulos a utilizar, presencia de ava-
tares, etc.). El propósito de este estudio experimental consiste en comparar la eficacia
de un tratamiento combinado, exposición a la realidad virtual y tratamiento cognitivo
conductual (VRET), con un acercamiento tradicional cognitivo-conductual (CBT). Quince
pacientes con agorafobia crónica recibieron un tratamiento VRET en 3D y 13 pacientes
recibieron un tratamiento CBT. Los dos grupos recibieron 11 sesiones. Las medidas
postratamiento incluyeron un breve test de evitación conductual (BAT). Los resultados
mostraron una significativa mejoría en los síntomas de la agorafobia (cogniciones,
sensaciones corporales, nivel de ansiedad y depresión) para los dos grupos que, en
general, permanecieron en un seguimiento a tres meses. Los BAT mostraron la capa-
cidad de los pacientes para exponerse a los estímulos fóbicos. Adicionalmente, el grupo
VRET mostró mayores mejorías, aunque ligeras, en comparación con el grupo CBT.
Estos resultados se discuten en relación con las dificultades del VRET para la agora-
fobia y en relación con la viabilidad de los siete ambientes fóbicos virtuales para
generar una exposición aceptable a los estímulos fóbicos.
PALABRAS CLAVE. Realidad virtual. Tratamiento cognitivo-conductual. Agorafobia.
Estudio experimental.
Agoraphobia (with or without panic) has been described as the most complex
phobia, the one most difficult to treat and the phobia that produces the highest level of
incapacitation in human beings (Mathews, Gelder, and Jonhston, 1981). This incapacitation
determines the lifestyle of the patients, affecting their entire daily functioning.
Epidemiological studies have shown that the pervasive nature of this problem, together
with its negative evolution, make agoraphobia a chronic disorder, if a patient does not
receive suitable treatment (ESEMeD, 2004; World Health Organization, 2004). Thus,
very frequently, agoraphobia patients require medication. Agoraphobics cope with phobic
stimuli in several ways. These strategies can be summarized in four behavioral patterns:
avoidance behaviors, escape behaviors; interoceptive avoidance (avoidance of situations
that provoke physiological symptoms similar to panic symptoms); and partial coping
behaviors (Baker, Patterson, and Barlow, 2002; Barlow and Craske, 1994; Otto, Safren,
and Pollack, 2004).
Partial coping behaviors seem to be a particularly good predictor of the negative
evolution of agoraphobia (Peñate, Pitti, Bethencourt, and Gracia, 2006; Pitti and Peñate,
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PEÑATE et al. Virtual reality exposure and cognitive-behavioral therapy in agoraphobia
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2003, Pitti, Peñate, and Bethencourt, 2006). These strategies allow patients, under certain
conditions, to cope with a phobic situation. They are frequently ritualistic behaviors,
including superstitions, the presence of ‘safety’ people (family, sanitary staff, etc.), and
even the use of certain substances or medicines. These strategies are learned, and tend
to become more pervasive as, although they allow the person to confront the phobic
environments, these behavior patterns become the only conditions under which the
person with agoraphobia is able to deal with the phobic stimuli.
Recently, there has been a rapid growth in the use of new technologies in
psychological treatment. The idea of using virtual reality (VR) technology for the
treatment of psychological disorders was first developed by the Human-Computer
Interaction Group of Clark University in Atlanta (North and North, 1994; North, North,
and Coble, 1996). They coined the term Virtual Reality Exposure Therapy (VRET), and
used this therapy with a patient with fear of flying, in a single-case design. They
obtained significant clinical results, diminishing phobic reactions. Since then, the use
of this technology has been applied to a variety of problems, such as panic disorder,
depression, or eating disorders (Wiederhold and Wiederhold, 2004). Nevertheless, the
greatest volume of research has been carried out into treatment of different phobias: the
environments and stimuli constructed by virtual reality technology have become a
useful procedure to expose patients to phobic stimuli similar to real situations.
The bases for the use of VR in the treatment of phobias are similar to those of
traditional psychological therapies founded on the model of emotional processing of
fear (Foa and Kozak, 1986). These psychological treatments have the following elements
in common: control of feared stimuli, exposure to these stimuli, and coping with them.
These common elements are the central mechanisms of the therapeutic change (Baker
et al., 2002). The treatment goal, according to this approach, consists of teaching the
person to reprocess the information derived from phobic stimuli, in an adaptive way.
In that sense, treatment needs to replicate the environmental contingencies that evoke
emotional non-adaptive responses (Salas-Auvert and Felgoise, 2003). Thus, studies
about empirically supported therapies for phobias have identified exposure-based treatment
and cognitive-behavioral therapy (where exposure is a central element) as efficient
therapies (Butler, Chapman, Form, and Beck, 2006; Chambless et al., 1996, 1998; Gros
and Antony, 2006). However, there is a paradoxical situation: the therapy phase, where
patients must cope with real phobic stimuli (in vivo exposure), poses a great therapeutic
limitation (Botella et al., 2002). When patients with phobias are exposed to objects,
places or situations, they face difficulties related with levels of fear, time, emotional
distress, etc. Thus, patients may refuse to participate or to continue in the therapy
phase. These limitations have stimulated the development of new, alternative methods
of in vivo exposure (v.g., Méndez, Orgilés, and Espada, 2004). In this sense, the phobic
environments designed by virtual reality techniques are a useful tool for exposing
patients to phobic stimuli similar to those present in real environments.
The first studies using VRET with phobic disorders were single-case designs (Botella
et al., 1998; Klein, 2000; North, and Coble. 1998; Wiederhold, Gevirtz, and Wiederhold,
1998). These studies reported positive results with both experimental and clinical
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PEÑATE et al. Virtual reality exposure and cognitive-behavioral therapy in agoraphobia
improvement, which led to new studies being designed. These included experimental
group designs, and increased the diversity of the phobic stimuli treated. VRET has been
applied to claustrophobia (Botella, Baños, Villa, Perpiñá and García-Palacios, 2000),
fear of flying (Maltby, Kirsch, Mayers, and Allen, 2002; Mülberger, Herrmann,
Wiedemann, Elgring, and Pauli, 2001; Mülberger, Wiedemann, and Pauli, 2003), fear
of snakes (García-Palacios, Hoffman, Carlin, Furness III, and Botella, 2002), social
phobia (Anderson, Zimand, Hodges, and Rothbaum, 2005; Harris, Kemmerling, and
North, 2002; North et al., 1998), and agoraphobia (Botella et al., 2004; Choi et al.,
2005; North et al., 1996; Vincelli et al., 2003). The conclusions of these reports indicated
that the virtual stimuli used to expose patients with phobias were as efficient as traditional
cognitive-behavioral treatments (Glantz, Rizzo, and Graap, 2003; Krijin, Emmelkamp,
Olafsson, and Biemond, 2004; Pull, 2005; Riva, 2003).
In spite of this, VRET is still at an early stage of development, and several questions
remain unsolved or require new experimental designs, such as: the quality of virtual
reality environments (especially the sensation of presence and the familiarity of stimuli),
the type of disorder, the type of sample (students, patients, etc.), the number and length
of sessions, combined use with other procedures, type of dependent variables (particularly
measures related with real coping such us the Behavioral Avoidance Tests, BAT), and
follow-up procedures.
If we analyze the use of VRET in agoraphobia, the results are unclear or inconsistent.
Thus, the initial work of North et al. (1996) reported an efficient application of VRET,
but they did not provide either BAT or follow-up data. The worst outcomes were
reported by Jang, Ku, Shin, Choi, and Kim (2000), who failed to provide a convincing
sense of presence in the virtual environment. However, recent studies have provided
better results. Studies such us that reported by Botella et al. (2004), Choi et al. (2005)
or Vincelli et al. (2003) have shown the efficiency of VRET with patients with agoraphobia,
including BAT and Follow-up, especially when VR is combined with cognitive-behavioral
procedures. Moreover, these studies indicate that VRET can have additional advantages
compared with traditional psychological treatment: there are more guaranties of exposure
(due to its use in a controlled situation), more possibilities of interoceptive exposure to
panic physiological signals, it can be an intermediate step, especially for patients who
refuse to expose to real environments, and it has formal advantages, because VRET
needs less time of application (Botella et al., 2004; Vincelli et al., 2003). However,
some difficulties specific to agoraphobia disorder still remain unsolved (Botella et al.,
2004; Glantz et al., 2003; Vincelli et al., 2003): the presence of avatars in virtual
environments is relevant in agoraphobia. As occurs in social phobia, the interaction
with human beings in different contexts produces an important part of anxiety responses.
Thus, the presence of avatars is necessary to create more realistic environments. Another
problem is that in agoraphobia there is not one precise stimulus that provokes the
anxiety crisis (as in specific phobias), but several environments, which are not always
the same from one patient to other. Furthermore, exposure is a complex task for patients
with severe agoraphobia (when patients have difficulties in just leaving their homes).
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PEÑATE et al. Virtual reality exposure and cognitive-behavioral therapy in agoraphobia
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This experimental study (Montero and León, 2007) aims to provide information
about some of these problems. The objectives are to test the efficacy of a combined
therapeutic program, VRET and cognitive-behavioral therapy, compared with the efficacy
of a traditional cognitive-behavioral approach. These programs were applied to a sample
of patients with chronic agoraphobia (two or more years under psycho-active drug
treatment). VRET was carried out with seven virtual environments that represent possible
phobic stimuli for agoraphobia patients (a square and a street, an airport building and
plane, a bank office, an elevator and underground car park, a beach, a highway, and a
cableway). Some of the environments can be modified according to the number of
persons in them (25 persons maximum), time of day, and climate. A 3D presentation
will be used to create a better sense of presence. The report was edited according to the
norms established by Ramos-Álvarez, Valdés-Conroy, and Catena (2006).
Method
Participants
Thirty seven patients with a diagnosis of agoraphobia (with/without panic disorder)
participated in the study. They were sent to the Psychiatry Service of the University
Hospital of the Canary Islands (Hospital Universitario de Canarias, HUC) by mental
health community units. There were 27 women and 10 men. Mean age was 38 years
(range: 17 to 60). The average time of evolution of agoraphobia was 10 years (range:
2 to 41). These participants were assigned to two experimental groups: cognitive-
behavioral treatment (CBT) and combined treatment of cognitive-behavioral and VR
treatment (VRET). The assignment took into account both gender and time of evolution
of the disorder. The sample was distributed as shown in Table 1.
TABLE 1. Distribution of agoraphobia patients into two groups of treatment:
cognitive-behavioral treatment (CBT) and combined treatment of cognitive-
behavioral and RV treatment (VRET), according to gender,
age and time of disorder evolution.
Treatment group
N
Gender
Age
Years of disorder
Male
Female
Mean / range
Evolution mean /
range
CBT
16
4
12
38.50 / 27-58
7.50 / 2-41
VRET
21
6
15
35 / 17-60
9 / 2-39
All treatment sessions were carried out by an experienced clinical psychotherapist
(trained in cognitive-behavioral therapies), and two helpers (graduate psychologists).
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PEÑATE et al. Virtual reality exposure and cognitive-behavioral therapy in agoraphobia
Materials and apparatus
A variety of different instruments were used to assess and verify the diagnosis of
agoraphobia, to determine the anxiety level of the virtual environments for each patient,
and to assess therapeutic progress. Similarly, seven different virtual environments were
developed. These environments represented seven possible phobic stimuli for patients
with agoraphobia.
To verify the diagnosis of agoraphobia in the patients from the HUC psychiatry
service, two instruments were administered:
– The Composite International Diagnostic Interview (CIDI, 2.1). CIDI-2.1 was
elaborated in 1997 by the World Health Organization, and this interview has
remained with similar contents, with slight changes (Kessler and Üstün, 2004).
It is a structured interview for major mental disorders, according to CIE-10
criteria (World Health Organization, 1992). Mental disorders are estimated both
for lifetime and 12-month prevalence. We adapted CIDI only to those questions
and criteria related with agoraphobia
– Cuestionario de Agorafobia (Agoraphobia Questionnaire ) (Echeburúa and Co-
rral, 1995). This questionnaire measures a general level of agoraphobia, with 69
items, Likert scale. It is divided in two parts: the first part examines manifest
behavior, cognitions, and psycho-physiology reactions, related to agoraphobic
situations (both, alone or with other people). The second part examines the
response variations as a function of factors that increase and decrease agoraphobic
behavioral patterns. The authors describe appropriate psychometric properties
for agoraphobia severity and for the selection of target-behaviors in agoraphobia
disorders.
To determine the level of anxiety elicited by the virtual environments, patients
were asked to rate each environment according to their ability to cope with it, both
alone or accompanied. A seven-point scale was used 0 (no problem to cope with) 7
(unable to cope with). At the same time, two physiological measures were taken to
verify the subjective anxiety reported for each environment: cardiac pulse and skin
conductance level. Both measures were assessed by a biofeedback system, PowerLab
16SP model (AD Instruments).
To assess treatment efficacy, the following instruments were used:
– Agoraphobic Cognition Questionnaire (ACQ) (Chambless, Caputo, Bright, and
Gallagher, 1984). This instrument was developed to assess ‘fear to fear’.
Specifically, the ACQ assesses catastrophic thoughts about both the physical
and social consequences of panic attack. It contains 14 items. Response choice
ranged from 1 (I never think this) to 5 (always). The Spanish translation of this
scale was used (Comeche, Diaz, and Vallejo, 1995).
– Body Sensation Questionnaire (BSQ) (Chambless et al., 1984). This is a 17-
item questionnaire, related to physical and physiological body responses.
Respondents are asked about the level of fear that these sensations provoke in
them, on a five-point scale: 1 (not worried) to 5 (extremely). Again, the Spanish
translation of this scale was used Comeche et al., 1995).
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PEÑATE et al. Virtual reality exposure and cognitive-behavioral therapy in agoraphobia
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– Beck Anxiety Inventory (Beck and Steer, 1990). This is a self-administered
inventory to assess the general level of anxiety. The 21 items reflect physiological
reactions, somatic complaints, and cognitions about the anxiety crisis. The scale
must be responded to according to occurrence in the last week, on a four-point
scale (from no to very).
– Beck Depression Inventory-II (BDI-II, Beck, Steer, and Brown, 1996). This is
the second version of a 21-item inventory developed to assess depression severity.
The current version is adapted to the DSM-IV criteria for depression (American
Psychiatric Association, 1994), and allows appraisal of four categories of depression
(no, mild, moderate, and severe).
– Subjective Unit of Anxiety (SUA). The environments were rated on a ten-point
scale: 0 (no anxiety), and 10 (maximum level of anxiety). These measurements
were taken at the end of all sessions.
– Behavioral Avoidance Test. Additionally, another measurement was taken: at the
end of the program, patients were encouraged to cope with a real scenario
similar to the virtual environment entitled ‘square and street‘. Patients were
accompanied by a therapist helper to this real street, and were asked to walk
there for ten minutes (maximum). They were informed that if they felt anxious
they could return to where the helper was waiting (they could also refuse to
carry out the task). A time measurement (minutes in the street) was taken.
Virtual environments. Seven virtual environments were developed to reflect seven
possible phobic stimuli for agoraphobia patients: a square and street, an airport building
and plane, a bank office, an elevator and underground car park, a beach, a highway, and
a cableway. These environments are designed on OpenGL, and based on a Torque
engine (Garage Games). In Figure 1 there is a picture of each environment.
FIGURE 1. Photographs of the seven virtual environments designed.
Square and street
Bank office
Airport
building
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PEÑATE et al. Virtual reality exposure and cognitive-behavioral therapy in agoraphobia
Underground car park
Cableway
Highway
Beach
The Nvidia Quadro FX3000O was used as graphical support due to the need to
move among large spaces and textures in a realistic way. A projection system formed
by two video-projectors (F1Design with 3000 lumens and 1024 x 768 resolutions) were
also used. These videos project a linearly polarized image for each eye on the same
zone of the screen and the patient uses glasses with polarized filters to produce a 3D
effect. The image is projected onto a special screen, with a surface of 2.5m x 2m. The
screen and the rest of the components are installed in a dark room to produce the
maximum sensation of presence.
The patient has a wireless joystick to move around the virtual environments. Likewise,
there is a DTS 7.1 audio system installed with 7 loudspeakers and subwoofer, to generate
3D sound (surround). The systems are controlled by an Intel PIV computer.
Design
An experimental group design was used, with measures at three stages: pre-treatment,
post-treatment, and 3 months follow-up. The experimental groups were composed of
patients with agoraphobia. The independent variable was type of treatment. One group
received cognitive-behavioral treatment (CBT) and the second group received a combined
treatment of cognitive-behavioral treatment and VR exposure (VRET). Both treatment
programs had 11 sessions, with duration of 35-45 minutes per session.Sessions were
conducted individually by the same therapist at the rate of one session per week. The
outline of the programs is summarized in Table 2.
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TABLE 2. Development of the session-by-session contents of both CBT treatment
group and VRET treatment group.
Sessions
1º
2º
3º
4º
5º
6º
7º
8º
9º
10º
11º
CBT
PE
AMT
AMT
IVE
IVE
IVE
IVE
IVE
IVE
IVE
IVE
VRET
PE
AMT
AMT
IVE
VRE
IVE
VRE
IVE
VRE
IVE
VRE
Notes. PE: psycho-education about agoraphobia. AMT: anxiety management training. IVE: encouragement of
in vivo exposure with AMT. VRE: virtual reality exposure.
The first three sessions were identical for both the CBT group and the VRET
group.
Session 1 was a psycho-educational session about agoraphobia. The therapist
explained the concept of agoraphobia; its origins and determinants; its cognitive, motor
and physiological symptoms and its development and course. Finally, she discussed the
particular nature of agoraphobia for each patient. In sessions 2 and 3, patients were
instructed in an anxiety management program, similar to that of Craske, Barlow, and
Meadows (2000): identification of phobic situations, management of negative activation
(training in controlled breathing3 and relaxation), and cognitive restructuring and self-
instructions in the management of thoughts and irrational ideas (especially catastrophic
thoughts). Interoceptive exposure was also trained.
The remaining 8 sessions were specific to each treatment group: IVE was used in
the CBT group. In these sessions, patients were encouraged to confront phobic
environments, and to use AMT to cope with phobic stimuli. In the following sessions,
patients discussed with the therapist about his/her weekly work in coping with phobic
situations. For the VRET group there was a combination of both IVE sessions and VRE
sessions. In the VRE sessions patients were exposed to the four virtual environments
that had produced most anxiety in a previous test. The exposure took 15-20 minutes,
combined with the use of AMT to cope with the anxiety situation. Strategies of partial
coping style received special attention from the therapist.
As dependent variables, the following data were collected: cognitive and overt
behaviors related with agoraphobia (AGF questionnaire), agoraphobic cognitions (ACQ),
subjective body sensations (BSQ), general anxiety (BAI), general depression (BDI-II),
SUA average, and BAT. Measurements were taken before treatment began (pre),
immediately after the treatment finished (post), and at 3 months (follow-up). SUA-
measurements were taken in each session. In the VRET group these measures corres-
ponded to the virtual environments of the VRE sessions, or, for the IVE sessions, were
3 Especially, we take into account data provided by Bornas et al. (2006).
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PEÑATE et al. Virtual reality exposure and cognitive-behavioral therapy in agoraphobia
related to in-vivo exposure in previous days (if this had taken place). In the CBT group
these measures only corresponded to in-vivo exposure in previous days. BAT measures
were collected at the end of the treatments.
Due to the fact that the patients with chronic agoraphobia were referred to the
service with some pharmacological treatment (or self-medicated), all patients were
matched in psycho-active drugs, by the administration of paroxetine, according to APA
guide (2004). Pharmacological discontinuation was assessed by the psychiatry service
from post-treatment until three months follow-up.
Procedure
An information campaign was carried out among the mental health units of the
island of Tenerife. The campaign provided information about the existence of a special
service in the Hospital Universitario de Canarias (HUC) for the treatment of agoraphobia.
Psychiatrists and psychologists were asked to send anyone with chronic agoraphobia (at
least two years of treatment) to this service.
As soon as a patient was referred to the service, assistants were instructed to
administer the CIDI interview (agoraphobia contents) and the Cuestionario de Agora-
fobia. If the patient met the CIE-10 diagnostic criteria for agoraphobia, he/she was
informed about the protocol to follow: progressive discontinuation of the current medication
(if it was necessary), and administration of paroxetine. One month later the person
would be included in one of the two groups of treatment (CBT and VRET). This
assignment took into account both gender and years of evolution of agoraphobia.
If the person accepted, they signed the consent form, and the assistants began with
the administration of pre-treatment measures. In addition, patients in the VRET group
were trained in the use of the VR system and, once they controlled the system, they
were asked to rate (0 to 7, alone or accompanied by someone) the anxiety level of each
one of the seven VR environments. In the CBT group, patients were asked to identify
and to describe their most phobic situations.
Once the therapy sessions had started, if the therapist detected symptoms of psychosis,
dementia, alcoholism or severe personality disorders, these patients were excluded.
Results
Eight patients dropped out for different motives (no motivation, non-agreement
with therapy procedure, expectancies, etc.) or due to the therapist’s decision, according
to the criteria described above. These eight patients correspond to four males and four
females; two had an agoraphobia evolution time (chronic level) of between 2-5 years,
three between 6-10 years, and three more than 10 years. By treatment, three correspond
to CBT, and five to VRET. At follow-up, one VRET patient refused to come. In this
sense, the final sample was composed of 13 patients in the CBT group and 15 patients
in the VRET group.
None of the χ2 associated to those variables was statistically significant, according
to drop out or not: for gender, χ2 = 2.53; chronic level (the three levels mentioned),
(1)
χ2 = .38; and treatment, χ2 = .2.
(2)
(1)
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