Acrophobia
Conditions
Keywords
virtual reality exposure therapy, waitlist control design, single session exposure, emotion-driven behavior, respiration
Brief summary
In recent years, in the treatment of phobias, exposure therapy in virtual reality is becoming more and more popular as an alternative for in-vivo exposure. Effectiveness of virtual reality exposure therapy (VRET) is comparable to in-vivo exposure therapy, though several characteristics of the VRET have an impact on the outcome of the therapy (e.g., immersion into the virtual environment (VE), familiarity with the VE). Additionally, the use of VRET varies from multiple exposure sessions to single-session VRET. Single-session therapy has an economic advantage and in in-vivo, post therapy outcomes show good results. In virtual reality, the assessment of outcome post therapy and in follow-up of single-session therapies is still needed for an evaluation of this approach. As an outcome measure, behavioral assessments are especially relevant for effectiveness studies as in fear of heights it is closer to the individual's life to know how high they voluntarily go up a building than to have hypothetical self-report questionnaire results. Much research has been conducted on physiological correlates of the subjective experience of fear in exposure therapy as they are assumed to be a prerequisite for effective exposure treatment. Skin conductance level (SCL) and heart rate can be used for objective manipulation checks of exposure therapy. SCL is found to increase during fearful situations independent of setting while heart rate only increases during in-vivo exposure. Contrary to heart rate, heart rate variability (HRV) is not thoroughly studied in VRET yet. HRV is associated with the adaptability of an organism to new environments and cognitive functioning. High Frequency HRV is found to be reduced in individuals with mental disorders, and positive and negative mood inductions lead to differential HRV responses overall. Respiration is a well-studied correlate of emotional experience and especially of the experience of fear and anxiety. In a series of experiments, it was found that sighing is tightly associated with relief in or after fearful or stressful situations and might become maladaptive when used disproportionally often. This study shows that respiration parameters have an impact on the handling of fearful situations in a reciprocal way. On the one hand, fear leads to an increased respiration rate and sigh rate while on the other hand, an altered sigh rate or respiration rate might have an impact on the experience of fear and be used as a defensive reaction to a fearful situation. As such, specific respiration patterns might act as emotion-driven behaviors (EDB). EDBs are responses to emotions that result in a short-term reduction of a negative state while in long-term support the maintenance of the phobia. The aim of this study is to examine the effectiveness of a single-session VRET for acrophobia with a multimethod outcome design. Familiarity of the setting will be high with the use of a well-known tower in this area. Immersion into the VE will be assessed with a presence questionnaire. For a manipulation check, physiological data will be assessed, i.e., SCL, heart rate and HRV. Primary outcome measure will be a behavioral approach test (BAT) as behavioral assessment. Additionally, after four weeks, a follow-up assessment will investigate the stability of the effectiveness of the VRET in comparison to a waitlist control group. A second aim of this study is to investigate the impact of respiration as an EDB on the effectiveness of an exposure therapy. Therefore, the association between respiration and outcome of the VRET will be analyzed. Hypothesis 1: Participants in the VRET condition show less height avoidance in the BAT after the intervention than participants in the control condition. Hypothesis 2: Participants in the VRET condition show less height avoidance in the BAT in a four-week follow-up assessment than participants in the control condition. Hypothesis 3: Participants in the VRET condition score significantly lower on the Acrophobia Questionnaire at follow-up than participants in the control condition. Hypothesis 4: During the VRET, breath holding is used as EDB. Participants that hold their breath, profit less from the VRET than participants that do not hold their breath. Hypothesis 5: During the VRET, sighing is used as EDB. Participants that sigh, profit less from the VRET than participants that do not sigh.
Interventions
BEHAVIORALvirtual reality exposure for acrophobia
The setting of the virtual reality is the Gasometer Oberhausen, Europe's largest disc-type gas container which is one of the most famous high buildings in the area. After a baseline phase, participants will undergo a gradual exposure. Participants will first look up to the building and then be guided upstairs to have an exposure phase on 11 floors. On the highest floor they will walk around a gallery. In the end, there will be a recovery phase.
BEHAVIORALmovie
Participants will watch a movie without height content for the same amount of time as the virtual reality exposure will need.
Sponsors
Ruhr University of Bochum
University of Witten/Herdecke
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
TREATMENT
Masking
NONE
Masking description
All roles are aware of the fact that the virtual reality exposure is the primary intervention. No information is given to the participant about the impact of the video in the waitlist control group.
Intervention model description
Participants are assigned to one of two conditions (virtual reality vs. waitlist control) for the initial phase. In the second phase the waitlist control group receives the virtual reality exposure while the other group does not receive a second intervention.
Eligibility
Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
Yes
Inclusion criteria
* diagnosed acrophobia * read, speak and write in German language
Exclusion criteria
* current panic disorder * lifetime psychotic disorder * current suicidality * neurological disorder * current substance use disorder
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Behavioral Approach Test Post | Within 1 hour after treatment /placebo intervention | Participants are asked to walk up fire exit stairs of the university building where the treatment is applied. The number of steps upstairs is counted as dependent measure. |
| Behavioral Approach Test Follow-up | Four weeks +/- 3 day after the treatment / placebo intervention | Participants are asked to walk up fire exit stairs of the university building where the treatment is applied. The number of steps upstairs is counted as dependent measure. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Acrophobia Questionnaire Follow-up | Four weeks +/- 3 day after the treatment / placebo intervention | Questionnaire by Cohen (1977); The scale ranges from 0 - not at all frightening to 6 - very frightening with a higher score indicating more anxiety. A total maximum score is 120 and minimum score 0. |
| Sigh Rate | During virtual reality exposure session, at baseline (1; 5 minutes), on each floor of the tower (2-14; 3 minutes, in total 39 minutes) and in recovery phase (15; 5 minutes) | Measured with inductive plethysmography and analyzed via ANSLAB |
| Number of Apnoeas | During virtual reality exposure session, at baseline (1; 5 minutes), on each floor of the tower (2-14; 3 minutes, in total 39 minutes) and in recovery phase (15; 5 minutes) | Pauses after inspiration and expiration longer than 5 seconds, measured with inductive plethysmography and analyzed via ANSLAB |
| Respiration Rate | During virtual reality exposure session, at baseline (1; 5 minutes), on each floor of the tower (2-14; 3 minutes, in total 39 minutes) and in recovery phase (15; 5 minutes) | Measured with inductive plethysmography and analyzed via ANSLAB |
| Respiratory Instability | During virtual reality exposure session, at baseline (1; 5 minutes), on each floor of the tower (2-14; 3 minutes, in total 39 minutes) and in recovery phase (15; 5 minutes) | Measured with inductive plethysmography and analyzed via ANSLAB |
| Subjective Units of Discomfort Change | During virtual reality exposure session, at baseline (1; minute 1), on each floor of the tower (2-14; between minute 6 and 44) and in recovery phase (15; minute 50) | Participants are asked how fearful they are on a scale from 0 to 10. Original scale by Wolpe & Lazarus (1966) |
| Heart Rate | During virtual reality exposure session, at baseline (1; 5 minutes), on each floor of the tower (2-14; 3 minutes, in total 39 minutes) and in recovery phase (15; 5 minutes) | Measured with Electrocardiogram and analyzed via ANSLAB |
| Heart Rate Variability | During virtual reality exposure session, at baseline (1; 5 minutes), on each floor of the tower (2-14; 3 minutes, in total 39 minutes) and in recovery phase (15; 5 minutes) | Measured with Electrocardiogram and analyzed via ANSLAB |
| Skin conductance level | During virtual reality exposure session, at baseline (1; 5 minutes), on each floor of the tower (2-14; 3 minutes, in total 39 minutes) and in recovery phase (15; 5 minutes) | Skin conductance is recorded continuously with two electrodes placed on the medial phalanxes of the index and middle fingers of the nondominant hand. |
| Video recording | During virtual reality exposure session, at baseline (1; 5 minutes), on each floor of the tower (2-14; 3 minutes, in total 39 minutes) and in recovery phase (15; 5 minutes) | A rating system for signs of muscular tension during virtual reality exposure will be designed. Therefore, in a first step it will be assessed whether signs of muscular tension are visible overall. In a second step, all signs from up to 10 randomly picked participants will be noted from two different raters in order to design a rating scale. This scale will then be applied to the rest of the participants by 2 independent raters and finally correlated with the post outcome measures and follow-up outcome measures. |
Other
| Measure | Time frame | Description |
|---|---|---|
| Anxiety Sensitivity Scale 3 Follow-up | Four weeks +/- 3 day after the treatment / placebo intervention | Questionnaire by Kemper, Ziegler & Taylor (2009); Scale ranges from 0 - very little to 4 - very much; a total maximum score is 64 and a minimum 0 with a higher score indicating more anxiety sensitivity. |
| Self-Evaluation of Breathing Questionnaire Follow-up | Four weeks +/- 3 day after the treatment / placebo intervention | Questionnaire by Courtney & Greenwood (2009) - translated with backtranslation by the author. The scale ranges from 0 - never to 3 - very often with a higher score indicating more breathing dirsturbances. A total maximum score is 75 and minimum 0. |
| Self-Evaluation of Breathing Questionnaire Pre | Right before the randomization to treatment / placebo condition - within 1 hour before intervention / placebo intervention | Questionnaire by Courtney & Greenwood (2009) - translated with backtranslation by the author. The scale ranges from 0 - never to 3 - very often with a higher score indicating more breathing dirsturbances. A total maximum score is 75 and minimum 0. |
| Beck Depression Inventory II Follow-up | Four weeks +/- 3 day after the treatment / placebo intervention | Questionnaire by Beck, Steer & Brown (2001), German version by Hautzinger, Keller & Kühner (2009). The scale ranges from 0 to 3 with a higher score indicating more depressive symptoms. A total maximum score is 60 and minimum score 0. |
| Beck Depression Inventory II Pre | Right before the randomization to treatment / placebo condition - within 1 hour before intervention / placebo intervention | Questionnaire by Beck, Steer & Brown (2001), German version by Hautzinger, Keller & Kühner (2009). The scale ranges from 0 to 3 with a higher score indicating more depressive symptoms. A total maximum score is 60 and minimum score 0. |
| Igroup Presence Questionnaire | Within 30 minutes after virtual reality exposure (treatment) | Questionnaire by Schubert, Friedmann & Regenbrecht (2001) to measure the feeling of presence in the virtual reality. Scale ranges from -3 - not at all to +3 - a lot with a total maximum score of 42 and minimum -42. A higher scores indicates a higher feeling of presence in the virtual reality. |
| Simulator Sickness Questionnaire | Within 30 minutes after virtual reality exposure (treatment) | Questionnaire by Kennedy, Lane, Berbaum & Lilienthal (1993) to measure simulator sickness in the virtual reality. Scale ranges from 0 - not at all to 3 - strongly with a total maximum score of 48 and minimum 0. A higher scores indicates a higher feeling of simulator sickness in the virtual reality. |
| Mini-DIPS (Diagnostisches Interview bei psychischen Störungen; english: diagnostic interview of mental disorders) | Within a month before the treatment / placebo intervention | Diagnostic interview to diagnose acrophobia and to exclude panic disorder. Interview by Margraf & Cwik (2017) |
| Behavioral Approach Test Pre | Right before the randomization to treatment / placebo condition - within 1 hour before treatment or placebo intervention | Participants are asked to walk up fire exit stairs of the university building where the treatment is applied. The number of steps upstairs is counted as dependent measure. BAT pre is assessed in order to ensure an effective randomization. |
| Acrophobia Questionnaire Pre | Within a month before the treatment / placebo intervention | Questionnaire by Cohen (1977); Screening for people with fear of hights and in order to ensure an effective randomization. The scale ranges from 0 - not at all frightening to 6 - very frightening with a higher score indicating more anxiety. A total maximum score is 120 and minimum score 0. |
| Anxiety Sensitivity Scale 3 Pre | Right before the randomization to treatment / placebo condition - within 1 hour before intervention / placebo intervention | Questionnaire by Kemper, Ziegler & Taylor (2009); Scale ranges from 0 - very little to 4 - very much; a total maximum score is 64 and a minimum 0 with a higher score indicating more anxiety sensitivity. |
Contacts
Primary ContactJohannes Michalak, PhD
Backup ContactNaomi Lyons, M.Sc.
Outcome results
None listed