Improving the Efficacy of Exposure Therapy for the Treatment of Cockroach Phobia

The aim of this study is to test the efficacy and efficiency of the Projection-Based augmented reality therapy under two conditions: multiple stimuli (different types of cockroaches) (P-ARET MS) versus single stimulus (one cockroach) (P-ARET SS) for the treatment of participants diagnosed with cockroach phobia.

Specific phobia (SP) refers to an extreme and persistent fear of a specific object or situation that is out of proportion to the actual danger or threat. SP is the most prevalent anxiety disorder with substantial impairment and comorbidity. Animal fear is one of the most prevalent subtypes of SP. In vivo exposure is the treatment of choice for this problem, but this technique presents limitations in its implementation related to the access and acceptability (i.e., low acceptance on the part of patients and therapists, high dropout rates, limited access to the treatment and, difficulties in its application in the clinical context). Augmented Reality (AR) offers some advantages in delivering the exposure technique: 1) Exposure to multiple virtual stimuli; 2) Going beyond reality; 3) Allowing complete control over the situation; 4) It allows privacy and confidentiality. Particularly, the most significant aspect of AR is that the virtual elements add relevant and helpful information to the physical information available in the real world.

We pretend to go a step beyond and explore ways of optimizing exposure therapy based on the inhibitory learning approach. AR can maximize some strategies like "variability" (varying stimuli, durations, levels of intensity, or the order of the hierarchy items), greater control by the therapists or "exposure to multiple contexts" which can produce a positive effect in terms of fear renewal and generalization of the results. Therefore, the aim of this study is to test the efficacy and efficiency of varying the phobic stimuli during the ARET: using multiple stimuli (MS) (P-ARET MS) versus single stimulus (SS) (P-ARET SS) in participants with cockroach phobia.

The Randomized Clinical Trial (RCT) will be conducted following the Consolidated Standards of Reporting Trials (CONSORT: http://www.consort-statement.org) and the SPIRIT guidelines (Standard Protocol Items: Recommendations for Intervention Trials). Participants (N = 80) who received a diagnosis of SP for cockroaches (DSM-5), will be randomized into two experimental conditions: 1) Projection-based augmented reality therapy (P-ARET) with Multiple Stimuli (MS) (P-ARET MS); 2) Projection-based augmented reality therapy (P-ARET) with Single Stimulus (SS) (P-ARET SS). Five evaluation moments will be included: pre-intervention, post- intervention, and 1-, 6- and 12-month follow-ups.

Eligibility Criteria:
Inclusion Criteria:

* Being at least 18 years old
* Meeting DSM-5 diagnostic criteria for SP (animal subtype) to cockroaches -
* Having a minimum of six-month duration of the phobia
* Sign an informed consent
* Presenting a score of at least 4 on the fear and avoidance scales of the diagnostic interview applied

Exclusion Criteria:

* Presence of another severe mental disorder that requires immediate attention
* Having current alcohol or drug dependence or abuse, psychosis or severe organic illness
* Currently being treated in a similar treatment program
* Being capable of inserting their hands in a plastic container with a cockroach (during the behavioral test)
* Receiving other psychological treatment during the study for cockroach phobia
* Start receiving pharmacological treatment during the study (or in case of being already taking them, change the drug or dose)