Journal of Behavior Therapy and Experimental Psychiatry
Affective outcomes of virtual reality exposure therapy for anxiety and specific phobias: A meta-analysis
Introduction
Anxiety and fear are concentrated emotional experiences that serve critical functions in organizing necessary survival responses (Fendt & Fanselow, 1999). Whilst properly functioning affective systems proffer responses that are adaptive, excessive trepidation is restrictive and may be a sign of dysregulated anxiety. Affective dysregulation, including anxiety disorders, specific phobias, as well as panic disorder and post-traumatic stress disorder (PTSD), may lead to significant impairments in normal life functioning. Repeated and early exposure to stress in persons with a particular genetic disposition may result in a decreased threshold for developing anxiety (Heim & Nemeroff, 1999). Over-excitation and deprivation can influence the affective system and may induce changes in the emotional circuitry of the brain that can contribute to stress-related psychopathology (Davidson, Jackson, & Kalin, 2000).
A good deal of research has shown that exposure therapy is effective for reducing negative affective symptoms (Rothbaum & Schwartz, 2002). In vivo exposure therapy has been found to have greater efficacy when compared to imaginal exposure, especially in the treatment of specific phobias (Emmelkamp, 2003). Exposure to emotional situations and prolonged rehearsal result in the regular activation of cerebral metabolism in brain areas associated with inhibition of maladaptive associative processes (Schwartz, 1998). Identical neural circuits have been found to be involved in affective regulation across affective disorders (De Raedt, 2006; Mineka, Watson, & Clark, 1998). Systematic and controlled therapeutic exposure to phobic stimuli may enhance emotional regulation through adjustments of inhibitory processes on the amygdala by the medial prefrontal cortex during exposure and structural changes in the hippocampus after successful therapy (Hariri, Bookheimer, & Mazziotta, 2000).
A novel tool for conducting exposure therapy is virtual reality exposure therapy (VRET), in which users are immersed within a computer-generated simulation or virtual environment (VE), that updates in a natural way to the users head and/or body motion. When a user is immersed in a VE, they can be systematically exposed to specific feared stimuli within a contextually relevant setting. VRET comports well with the emotion-processing model, which holds that the fear network must be activated through confrontation with threatening stimuli and that new, incompatible information must be added into the emotional network (Foa & Kozak, 1986; Wilhelm et al., 2005).
Empirical data from research assessing the efficacy of VRET on affective outcomes have been increasingly emerging over the last 10 years as VR systems have become less costly, more available and generally more usable. While much of the research to date has been comprised withcase studies, open clinical trials, and uncontrolled designs, a number of qualitative reviews (Botella et al., 2004; Glantz & Rizzo, 2003; Hodges, Anderson, Burdea, Hoffman, & Rothbaum, 2001; Krijn, Emmelkamp, Olafsson, & Biemond, 2004b; Pull, 2005) of initial VRET research have concluded that VRET has good potential as a treatment approach for several specific phobias (i.e. acrophobia, fear of driving, claustrophobia, aviophobia, and arachnophobia). The rationale for this view typically derives from early evidence that VRET produces better outcomes than imaginal exposure and that it provides equivalent outcomes and is a pragmatically attractive alternative to in vivo exposure (Emmelkamp, 2003). Further, these reviews qualitatively summarize findings from several studies that have yielded promising results with VRET in the treatment of PTSD and social anxiety disorder.
A potential problem in interpreting and reconciling findings about the nature and extent of affective changes ensuing from VRET is that a number of factors other than virtual reality exposure per se may be associated with such changes, including, for example, presence, immersion, anxiety and/or phobia duration, diagnostic groups, demographics (e.g. age, gender, and ethnicity). Furthermore, the vast majority of VRET studies have reported on small sample sizes and made use of inadequate null hypothesis significance testing.
Until large-scale studies on the affective effects of VRET are published, statistical meta-analyses represent an interim remedy. Such analyses provide estimates of a population effect size across independent studies. They increase statistical power to detect true nonzero population effects by lowering the standard error, and consequently narrowing the confidence intervals associated with the population effect size estimate (Cohn & Becker, 2003). Hence, a quantitative meta-analysis, as opposed to a qualitative review, might facilitate a better understanding of the variability and clinical significance of affective change subsequent to VRET. In view of this need, the present study sought to examine the magnitude of VRET-related changes in six domains and an overall effect size for affective functioning across studies using meta-analytic methodologies.
Section snippets
Study selection
The overall objective of study selection was to collect published journal articles that examined anxiety symptoms before and after VRET for treatment of anxiety disorders. A preliminary article search was conducted using MedLine (1990–2006), PsycLIT (1990–2006), EMBASE (1990–2006), Cochrane Library (1990–2006), and ISI Web of Science electronic databases (1990–2006). Standard searches were performed, which used keywords containing affective domains (anxiety related), as well as references to
Literature search
The results of the literature search produced 52 studies that had evaluated anxiety and/or phobia before and after VRET. Among these studies, 21 articles met the eligibility criteria for inclusion in the meta-analysis. Table 1 lists included studies’ sample size, affective domain assessed, and number of VRET sessions. Across studies the maximum combined sample size used for aggregated effect size calculations was 300 subjects.
Tests of homogeneity of variance
For all studies combined, initial assessment of homogeneity of
Discussion
The results of this meta-analysis revealed that VRET had statistically large effects on all affective domains, as well as all anxiety/phobia groupings evaluated. These effects were of the magnitude described in the literature as large (Cohen (1992), Cohen (1988)). Thus, VRET appears effective from a clinical psychology standpoint (bearing in mind that patients in most studies were selected after consideration of a variety of inclusion and exclusion criteria, meaning this conclusion may not
Conclusions
Given the currently available data, it appears that VRET is relatively effective from a psychotherapeutic standpoint in carefully selected patients. VRET can reduce anxiety and phobia symptoms. Whether the affective enhancements are directly related to VRET, or some other factor, remains to be specified, as do the clinical predictors for such improvements. The meta-analytic findings parallel qualitative reviews revealing that VRET has potential for the treatment of anxiety and several specific
References (50)
- et al.
Virtual reality treatment versus exposure in vivo: A comparative evaluation in acrophobia
Behavior Research and Therapy
(2002) - et al.
The neuroanatomical and neurochemical basis of conditioned fear
Neuroscience and Biobehavioral Reviews
(1999) - et al.
Virtual reality in the treatment of spider phobia: A controlled study
Behavior Research and Therapy
(2002) - et al.
The impact of early adverse experiences on brain systems involved in the pathophysiology of anxiety and affective disorders
Biological Psychiatry
(1999) - et al.
Treatment of acrophobia in virtual reality: The role of immersion and presence
Behavior Research and Therapy
(2004) - et al.
Virtual reality exposure therapy of anxiety disorders: A review
Clinical Psychology Review
(2004) - et al.
Repeated exposure of flight phobics to flights in virtual reality
Behavior Research and Therapy
(2001) - et al.
Clinical significance: History, application, and current practice
Clinical Psychology Review
(2001) The file drawer problem and tolerance for null results
Psychological Bulletin
(1979)- et al.
Virtual reality exposure therapy and standard (in vivo) exposure therapy in the treatment of fear of flying
Behavior Therapy
(2006)
Cognitive behavioral therapy for public-speaking anxiety using virtual reality for exposure
Depression and Anxiety
Virtual reality and psychotherapy
Studies in Health Technology and Informatics
Effectiveness of virtual reality exposure in the treatment of arachnophobia using 3d games
Technology and Health Care
Effects of group experiential cognitive therapy for the treatment of panic disorder with agoraphobia
Cyberpsychology and Behavior
The combination of estimates from different experiments
Biometrics
Statistical power analysis for the behavioral sciences
A power primer
Psychological Bulletin
How meta-analysis increases statistical power
Psychological Methods
Documenting the efficacy of virtual reality exposure with psychophysiological and information processing measures
Applied Psychophysiology Biofeedback
Emotion, plasticity, context, and regulation: Perspectives from affective neuroscience
Psychological Bulletin
Does neuroscience hold promise for the further development of behavior therapy? The case of emotional change after exposure in anxiety and depression
Scandinavian Journal of Psychology
The application of virtual reality to the treatment of PTSD following the WTC attack
Annals of the New York Academy of Sciences
Virtual reality treatment in acrophobia: A comparison with exposure in vivo
Cyberpsychology and Behavior
Behavior therapy with adults
Emotional processing of fear: Exposure to corrective information
Psychological Bulletin
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