Learning more about exposure therapy can help you make an informed decision about treatment and prepare you for what to expect.
Exposure therapy is a kind of behavioral therapy that is typically used to help people living with phobias and anxiety disorders. It involves a person facing what they fear, either imagined or in real life, but under the guidance of a trained therapist in a safe environment. It can be used with people of all ages, and has been found to be effective.
In exposure therapy, a person is exposed to a situation, event, or object that triggers anxiety, fear, or panic for them. Over a period of time, controlled exposure to a trigger by a trusted person in a safe space can lessen the anxiety or panic.
There are different kinds of exposure therapies. They can include:
- In vivo exposure. This therapy involves directly facing the feared situation or activity in real life.
- Imaginal exposure. It involves vividly imagining the trigger situation in detail.
- Virtual reality exposure. This therapy can be used when in vivo exposure isn’t realistic, like if someone has a fear of flying.
- Interoceptive exposure. This therapy involves purposefully triggering a physical sensation that is feared, but harmless.
A 2015 research review showed that within those kinds of exposure therapies there are different techniques like:
- Prolonged exposure (PE). This includes a combination of in vivo and imaginal exposure. For example, someone might repeatedly revisit a traumatic event by visualizing it, and talking about it with a therapist simultaneously, and then discussing it to gain a new perspective about the event.
- Exposure and response prevention (EX/RP, or ERP). Typically used for people with obsessive compulsive disorder (OCD), this involves doing exposure homework, such as touching something considered “dirty,” and then refraining from performing the compulsive behavior that is triggered from the exposure.
Generalized anxiety
Treatment for generalized anxiety disorder (GAD) can include imaginal exposure and in vivo, but in vivo exposure is not as common. The 2015 research review above showed that cognitive behavioral therapy (CBT) and imaginal exposure improved general functioning in people with GAD compared to relaxation and nondirective therapy.
There is not a lot of research with exposure therapy and GAD, and more is needed to further explore its effectiveness.
Social anxiety
In vivo exposure is typically used for people with social anxiety. This can include things like going to a social situation and not avoiding certain activities. The same 2015 research review above showed that exposure with or without cognitive therapy may be effective in reducing symptoms of social anxiety.
Driving anxiety
Virtual reality exposure therapy has been used to help people with a driving phobia. A small 2018 study found that it was effective in reducing driving anxiety, but more research still needs to be done with this specific phobia. Other therapies may need to be used alongside exposure therapy.
Public speaking
Virtual reality exposure therapy has been found to be effective and therapeutic to treat anxiety about public speaking for both adults and teens. One small 2020 study found that there was a significant decrease in self-rated anxiety about public speaking after a 3-hour session. These results were maintained 3 months later.
Separation anxiety
Separation anxiety disorder is one of the most common anxiety disorders in children. Exposure therapy is considered the top treatment for it. This involves exposing the child to feared situations and, at the same time, encouraging adaptive behavior and thinking. Over time, the anxiety lessens.
Obsessive compulsive disorder (OCD)
Exposure and response prevention (ERP) uses imaginal and in vivo exposure and is often used to help treat OCD. In vivo exposures are done in the therapy session as well as assigned for homework, and the response prevention (not engaging in compulsive behaviors) is part of that. An individual lets the anxiety decrease on its own instead of performing the behaviors that would get rid of the anxiety. When in vivo exposure is too hard or impractical, imaginal exposure is used.
While a 2015 research review showed that ERP was effective, ERP is comparable to cognitive restructuring alone and ERP with cognitive restructuring. Exposure therapy for OCD is most effective when guided by a therapist and not done independently. It’s also more effective when using both in vivo and imaginal exposure, as opposed to solely in vivo.
Panic disorder
Interoceptive exposure therapy is often used to treat panic disorder. According to a 2018 research review of 72 studies, interoceptive exposure and face-to-face settings, meaning working with a trained professional, were associated with better rates of effectiveness, and people were more accepting of the treatment.
Over a quarter of the people in the US population will have an anxiety disorder sometime during their lifetime.1 It is well established that exposure-based behavior therapies are effective treatments for these disorders; unfortunately, only a small percentage of patients are treated with exposure therapy.2,3 For example, in the Harvard/Brown Anxiety Research Project, only 23% of treated patients reported receiving even occasional imaginal exposure and only 19% had received even occasional in vivo exposure.4 In part, this may be a lack of well-trained professionals, because most mental health clinicians do not receive specialized training in exposure-based therapies.5,6
Another factor may be that many health care professionals do not understand the principles of exposure or may even hold (usually unfounded) negative beliefs about this form of treatment. Surveys of psychologists who treat patients with PTSD show that the majority do not use exposure therapy and most believe that exposure therapy is likely to exacerbate symptoms.7,8 However, individuals with trauma histories and PTSD express a preference for exposure therapy over other treatments.9 Furthermore, exposure therapy does not appear to lead to symptom exacerbation or treatment discontinuation.10 Indeed, a wealth of evidence indicates that exposure-based therapy is associated with improved symptomatic and functional outcomes for patients with PTSD.11
The available research literature suggests that exposure-based therapy should be considered the first-line treatment for a variety of anxiety disorders. Here we review a handful of the most influential studies that demonstrate the efficacy of exposure therapy. We also discuss theoretical mechanisms, practical applications, and empirical support for this treatment and provide practical guidelines for clinicians who wish to use exposure therapy and empirical evidence to guide their decision making.
Exposure therapy is defined as any treatment that encourages the systematic confrontation of feared stimuli, which can be external (eg, feared objects, activities, situations) or internal (eg, feared thoughts, physical sensations). The aim of exposure therapy is to reduce the person’s fearful reaction to the stimulus.
Graded exposure vs flooding
Most exposure therapists use a graded approach in which mildly feared stimuli are targeted first, followed by more strongly feared stimuli. This approach involves constructing an exposure hierarchy in which feared stimuli are ranked according to their anticipated fear reaction (Table 1). Traditionally, higher-level exposures are not attempted until the patient’s fear subsides for the lower-level exposure. By contrast, some therapists have used flooding, in which the most difficult stimuli are addressed from the beginning of treatment (an older variant, implosive therapy, is not discussed in this article). In clinical practice, these approaches appear equally effective; however, most patients and clinicians choose a graded approach because of the personal comfort level.12,13
In vivo vs imaginal
In vivo exposure refers to real-world confrontation of feared stimuli. Sometimes, in vivo exposure is not feasible (eg, it would be both difficult and hazardous for someone with combat-related PTSD to experience the sights, sounds, and smells of combat in real life). In such cases, imaginal exposure can be a useful alternative. In imaginal exposure, the patient is asked to vividly imagine and describe the feared stimulus (in this case, a traumatic memory), usually using present-tense language and including details about external (eg, sights, sounds, smells) and internal (eg, thoughts, emotions) cues.
In recent years, virtual reality exposure therapy (patients are immersed in a virtual world that allows them to confront their fears) has been examined as an alternative means of imaginal exposure, and preliminary data suggest that it can be quite effective.14,15 Imaginal exposures can also be useful for confronting fears of worst-case scenarios (eg, patients with obsessive-compulsive disorder [OCD] who imagine that they might contract a deadly illness, patients with social phobia who imagine that they are being ridiculed) to reduce the aversiveness of the thought.
What is already known about exposure therapy for anxiety disorder?
? Exposure therapy is defined as any treatment that encourages the systematic confrontation of feared stimuli, with the aim of reducing a fearful reaction. Over a quarter of the people in the US population will have an anxiety disorder sometime during their lifetime, and available research literature suggests that exposure-based therapies should be considered the first-line treatment for these disorders. Although it is well established that exposure-based therapies are effective treatments for these disorders, however, only a small percentage of patients are actually treated with this approach.
What new information does this article provide?
? We review the results of a handful of the most influential studies that demonstrate the efficacy of exposure therapy and disseminate information about the theoretical mechanisms, practical applications, and empirical support for this treatment. In addition, we provide practical guidelines for clinicians who wish to use exposure-based therapies and empirical evidence to guide their decision making.
What are the implications for psychiatric practice?
? In clinical practice, exposure-based therapies for anxiety disorders are underutilized, which highlights the need for additional dissemination and training. We hope the dissemination of the theoretical mechanisms, practical applications, and empirical support for exposure-based therapies in this article will encourage mental health practitioners to embrace this modality as a viable and easily accessible option in the treatment of anxiety disorders.
Internal vs external
Exposures can target internal and/or external cues. Exposures to external cues include a spider-phobic patient handling a spider, or a height-phobic patient systematically approaching increasing heights in a skyscraper. Using exposure to internal cues, a patient with panic disorder can run in place to experience physiological sensations (eg, heart palpitations) that elicit anxious reactions, a patient with generalized anxiety disorder (GAD) can purposefully induce worry thoughts, a patient with PTSD can revisit traumatic memories, and a patient with OCD can intention-ally evoke intrusive and aversive thoughts.
With or without relaxation
One of the earliest variations of exposure therapy was systematic desensitization, in which patients engage in imaginal exposure to feared stimuli while simultaneously undergoing progressive muscle relaxation.16 Subsequent dismantling studies have shown that exposure, rather than relaxation, is the active ingredient and that relaxation does not improve outcomes.17 The addition of relaxation exercises has been counterproductive in some patients, such as those with panic disorder.18 Because of the apparent importance of interoceptive exposure (ie, learning to tolerate uncomfortable physical sensations), relaxation exercises aimed at decreasing these sensations may actually attenuate the outcome of therapy, in much the same way as does the use of as-needed short-acting benzodiazepines.19
Efficacy of exposure therapy
Several studies have demonstrated the efficacy of exposure-based therapies for anxiety disorders, a finding that is summarized in several published meta-analyses.20,21 st22 examined the effects of single-session in vivo exposure (that lasts 1 to 3 hours) for patients with specific phobias. At posttreatment follow-up (after an average of 4 years), 90% of these patients still had significant reduction in fear, avoidance, and overall level of impairment and 65% no longer had a specific phobia.
Barlow and colleagues23 investigated the effects of interoceptive exposure with components of cognitive restructuring (cognitive-behavioral therapy [CBT]), imipramine, and a combination of the two in patients with panic disorder. At first, all treatments appeared equally efficacious; however, at 6 months’ follow-up, 32% of patients in the CBT group continued to maintain their treatment gains compared with 20% in the imipramine group and 24% in the combined-treatment group.
Foa and colleagues24 randomized patients with OCD to receive in vivo exposure and response prevention, clomipramine, or a combination of both. For patients who completed the study, 86% in the exposure group improved on a measure that examined the frequency and severity of obsessions and compulsions compared with 48% in the clomipramine group and 79% in the combined-treatment group.
Several others have also demonstrated the efficacy of exposure-based treatments or treatment components for patients with GAD, so-cial anxiety disorder, and PTSD.25-27
Theoretical mechanisms of exposure therapy
Biologically, the extinction of fear appears to be mediated by N-methyl-d-aspartate receptor activity in the basolateral amygdala, a finding that has led to the use of neuroplasticity compounds such as d-cycloserine to augment exposure.28,29 There are 4 major theories that attempt to explain the psychological mechanisms of exposure therapy: habituation, extinction, emotional processing, and self-efficacy (Table 2).
Habituation theory purports that after repeated presentations of a stimulus, the response to that stimulus will decrease.30 For example, initial exposure to ocean water can be cold. However, over time and with repeated exposures, the water feels less cold as the person acclimates. Similarly, when repeatedly facing a fear-provoking stimulus in exposure therapy, the patient experiences habituation, or a natural reduction in fear response. While many clinicians aim for habituation to occur within the session, researchers have found that optimal treatment effects occur during the period of learning consolidation between sessions.31,32
Extinction theory emerges from a classic conditioning model in which the unconditioned stimulus is a situation, place, or person that initially caused fear (the unconditioned response)-for example, a dog bite. Through the process of stimulus generalization, fear reactions become learned (conditioned response) and are elicited by other stimuli, such as dogs that are not dangerous (conditioned stimuli). Because of the aversiveness of the conditioned response, fearful individuals are motivated to avoid the conditioned stimuli, thus reinforcing avoidance behavior as well as the belief that relief from fear only comes from avoidance.33
Exposure therapy is thought to weaken the conditioned response through repeated exposure to the conditioned stimuli in the absence of the unconditioned stimulus. For example, exposure to dogs (conditioned stimuli) without being bitten (absence of unconditioned stimulus) weakens the relationship between the conditioned stimuli and the fear of conditioned response. One limitation of extinction theory is that most phobic patients do not identify an initial conditioning event.34
Emotional processing theory suggests that fear is stored in memory as a network of stimuli (eg, social gathering), response (eg, sweaty palms), and meaning (eg, “I’m not good at socializing, I’m a failure”) components.35 Fearful individuals are thought to ascribe faulty meanings to stimuli in a way that increases fear toward those stimuli. Exposure to fear-provoking stimuli is thought to result in a new way of processing information and to correct the faulty fear structure.36,37 For example, in patients with social anxiety disorder, social interactions can be perceived as rewarding, even if the patients have sweaty palms and feel some anxiety.
The self-efficacy theory focuses more on increasing skills and mastery over a situation or performance than on reducing a fear response directly.38 Persons with anxiety disorders tend to underestimate their capabilities to cope with fear. Therefore, persons able to face their fear and successfully tolerate it without avoiding it or withdrawing from it begin to realize they are more capable and resilient than they had imagined. Thus, they become more willing to face their fears in different contexts, thereby generalizing treatment effects.
These theoretical mechanisms of exposure are not mutually exclusive, and all might be correct for any given patient. With repeated exposures, patients experience reduced sensations of fear (habituation), learn a new set of associations (extinction), feel increasingly able to cope with fear (self-efficacy), and generate new interpretations of the meanings of previously feared stimuli (emotional processing).
Treatment guidelines
Treatment guidelines for clinicians who use exposure therapy are shown in Table 3. The first step in successful exposure therapy is the development of an exposure hierarchy. The patient and clinician brainstorm as many feared external and internal stimuli as possible and then rate them in order of difficulty. The most common ranking method is the Subjective Units of Discomfort (SUD) scale, which assigns a 0 to 100 numeric value to each item.39 (This scale can be found online in Wikipedia and at http://www.newworldencyclopedia.org/entry/Joseph-Wolpe.)
The next step is to conduct exposures in a gradual and systematic manner. Repeated use of the SUD scale will help track the patient’s fear level as it increases and decreases. Typically, a higher item is not attempted until the patient’s SUD level decreases significantly for a lower-ranked item.
During exposure therapy, safety behaviors should be eliminated to the extent possible. Safety behaviors refer to all unnecessary actions the patient takes to feel better or to prevent feared catastrophes. Left unchecked, safety behaviors can undermine the process of exposure therapy by teaching the patient a rule of conditional safety (eg, “The only way to be safe during a panic attack is to have my medication with me”) rather than a rule of unconditional safety (eg, “Panic attacks will not harm me, regardless of whether I am carrying my medications”).
Cognitive restructuring may also be used as an adjunct to exposure therapy. Cognitive restructuring refers to identifying and challenging irrational, unrealistic, or maladaptive beliefs. In patients with anxiety disorders, 2 of the more common faulty thinking patterns (ie, cognitive distortions) are probability overestimation and catastrophizing. Probability overestimation refers to the overprediction of unlikely outcomes, such as the belief that a commercial flight is highly likely to crash. Catastrophizing refers to the magnification of the consequences of aversive outcomes, such as the belief that making a mistake during a speech will lead to a lifetime of ridicule and ostracism. During the process of exposure exercises, the therapist helps the patient identify these cognitive distortions; examine the evidence for and against the beliefs; and rehearse new, more realistic ways of thinking.
Conclusion
Exposure-based therapies are highly effective for patients with anxiety disorders, to the extent that exposure should be considered a first-line, evidence-based treatment for such patients. In clinical practice, however, these treatments are underutilized, which highlights the need for additional dissemination and training. We hope this information will encourage clinicians to embrace exposure-based therapies for anxiety disorders as a viable and easily accessible treatment option.
References:
References
1. Kessler RC, Berglund P, Demler O, et al. Lifetime prevalence and age-of-onset distributions of DSM-IV disorders in the National Comorbidity Survey Replication [published correction appears in Arch Gen Psychiatry. 2005;62:768]. Arch Gen Psychiatry. 2005;62:593-602.
2. Torres AR, Prince MJ, Bebbington PE, et al. Treatment seeking by individuals with obsessive-compulsive disorder from the British Psychiatric Morbidity Survey of 2000. Psychiatr Serv. 2007;58:977-982.
3. Mancebo MC, Eisen JL, Pinto A, et al. The brown longitudinal obsessive compulsive study: treatments received and patient impressions of improvement. J Clin Psychiatry. 2006;67:1713-1720.
4. Goisman RM, Rogers MP, Steketee GS, et al. Utilization of behavioral methods in a multicenter anxiety disorders study. J Clin Psychiatry. 1993;54:213-218.
5. Davison GC. Being bolder with the Boulder model: the challenge of education and training in empirically supported treatments. J Consult Clin Psychol. 1998;66:163-167.
6. Crits-Christoph P, Frank E, Chambless DL, et al. Training in empirically validated treatments: what are clinical psychology students learning? Prof Psychol Res Pract. 1995;26:514-522.
7. Becker CB, Zayfert C, Anderson E. A survey of psychologists’ attitudes towards and utilization of exposure therapy for PTSD. Behav Res Ther. 2004;42:277-292.
8. van Minnen A, Hendriks L, Olff M. When do trauma experts choose exposure therapy for PTSD patients? A controlled study of therapist and patient factors. Behav Res Ther. 2010;48:312-320.
9. Becker CB, Darius E, Schaumberg K. An analog study of patient preferences for exposure versus alternative treatments for posttraumatic stress disorder. Behav Res Ther. 2007;45:2861-2873.
10. Foa EB, Zoellner LA, Feeny NC, et al. Does imaginal exposure exacerbate PTSD symptoms? J Consult Clin Psychol. 2002;70:1022-1028.
11. Foa EB, Hembree EA, Cahill SP, et al. Randomized trial of prolonged exposure for posttraumatic stress disorder with and without cognitive restructuring: outcome at academic and community clinics. J Consult Clin Psychol. 2005;73:953-964.
12. Ost LG, Alm T, Brandberg M, Breitholtz E. One vs five sessions of exposure and five sessions of cognitive therapy in the treatment of claustrophobia. Behav Res Ther. 2001;39:167-183.
13. Moulds ML, Nixon RD. In vivo flooding for anxiety disorders: proposing its utility in the treatment posttraumatic stress disorder. J Anxiety Disord. 2006;20:498-509.
14. Michaliszyn D, Marchand A, Bouchard S, et al. A randomized, controlled clinical trial of in virtuo and in vivo exposure for spider phobia. Cyberpsychol Behav Soc Netw. 2010;13:689-695.
15. Meyerbröker K, Emmelkamp PM. Virtual reality exposure therapy in anxiety disorders: a systematic review of process-and-outcome studies. Depress Anxiety. 2010;27:933-944.
16. Wolpe J. The systematic desensitization treatment of neuroses. J Nerv Ment Dis. 1961;132:189-203.
17. Telch MJ, Lucas JA, Schmidt NB, et al. Group cognitive-behavioral treatment of panic disorder. Behav Res Ther. 1993;31:279-287.
18. Schmidt NB, Woolaway-Bickel K, Trakowski J, et al. Dismantling cognitive-behavioral treatment for panic disorder: questioning the utility of breathing retraining. J Consult Clin Psychol. 2000;68:417-424.
19. Westra HA, Stewart SH, Conrad BE. Naturalistic manner of benzodiazepine use and cognitive behavioral therapy outcome in panic disorder with agoraphobia. J Anxiety Disord. 2002;16:233-246.
20. Norton PJ, Price EC. A meta-analytic review of adult cognitive-behavioral treatment outcome across the anxiety disorders. J Nerv Ment Dis. 2007;195:521-531.
21. Tolin DF. Is cognitive-behavioral therapy more effective than other therapies? A meta-analytic review. Clin Psychol Rev. 2010;30:710-720.
22. Öst LG. One-session treatment for specific phobias. Behav Res Ther. 1989;27:1-7.
23. Barlow DH, Gorman JM, Shear MK, Woods SW. Cognitive-behavioral therapy, imipramine, or their combination for panic disorder: a randomized controlled trial [published corrections appear in JAMA. 2000;284:2450; JAMA. 2000;284:2597]. JAMA. 2000;283:2529-2536.
24. Foa EB, Liebowitz MR, Kozak MJ, et al. Randomized, placebo-controlled trial of exposure and ritual prevention, clomipramine, and their combination in the treatment of obsessive-compulsive disorder. Am J Psychiatry. 2005;162:151-161.
25. Borkovec TD, Costello E. Efficacy of applied relaxation and cognitive-behavioral therapy in the treatment of generalized anxiety disorder. J Consult Clin Psychol. 1993;61:611-619.
26. Gerardi M, Cukor J, Difede J, et al. Virtual reality exposure therapy for post-traumatic stress disorder and other anxiety disorders. Curr Psychiatry Rep. 2010;12:298-305.
27. Heimberg RG, Liebowitz MR, Hope DA, et al. Cognitive behavioral group therapy vs phenelzine therapy for social phobia: 12-week outcome. Arch Gen Psychiatry. 1998;55:1133-1141.
28. Davis M. Role of NMDA receptors and MAP kinase in the amygdala in extinction of fear: clinical implications for exposure therapy. Eur J Neurosci. 2002;16:395-398.
29. Norberg MM, Krystal JH, Tolin DF. A meta-analysis of D-cycloserine and the facilitation of fear extinction and exposure therapy. Biol Psychiatry. 2008;63:1118-1126.
30. Groves PM, Thompson RF. Habituation: a dual-process theory. Psychol Rev. 1970;77:419-450.
31. Lang AJ, Craske MG. Manipulations of exposure-based therapy to reduce return of fear: a replication. Behav Res Ther. 2000;38:1-12.
32. Rowe MK, Craske MG. Effects of varied-stimulus exposure training on fear reduction and return of fear. Behav Res Ther. 1998;36:719-734.
33. Mowrer OH. Learning Theory and Behavior. New York: John Wiley and Sons; 1960.
34. Rachman S. The conditioning theory of fear-acquisition: a critical examination. Behav Res Ther. 1977;15:375-387.
35. Lang PJ. The application of psychophysiological methods to the study of psychotherapy and behavior modification. In: Bergin AE, Garfield SL, eds. Handbook of Psychotherapy and Behavior Change. New York: Wiley; 1971:75-125.
36. Foa EB, Kozak MJ. Emotional processing of fear: exposure to corrective information. Psychol Bull. 1986;99:20-35.
37. Craske MG, Kircanski K, Zelikowsky M, et al. Optimizing inhibitory learning during exposure therapy. Behav Res Ther. 2008;46:5-27.
38. Bandura A. Self-efficacy: toward a unifying theory of behavioral change. Psychol Rev. 1977;84:191-215.
39. Wolpe J. The Practice of Behavior Therapy. 4th ed. New York: Pergamon Press; 1990.
