A Protocol for a Virtual Reality Exposure Therapy for Fear of Flying.

Virtual Reality Exposure Therapy for Fear of Flying: Protocol for a Randomized Controlled Trial

This study aims to assess whether adding vibrotactile stimulation to visual and auditory stimulation increases the efficacy of VRET for FoF treatment. Eighty-four participants (18-65 years old) will be assigned to one of three intervention arms, namely the VRET with multimodal feedback (visual, auditory, and vibrotactile; VRET-M), the VRET with bimodal feedback (visual and auditory; VRET-B), or the imagery exposure treatment (IET) without sensory feedback. FoF-related symptoms (primary outcomes) will be measured administering the Fear of Flying Questionnaire-II (QPV-II), the Fear of Flying Scale (FFS), and the Visual Analogic Scale (VAS-A) before and after eight sessions of treatment, and at six- and 12-month follow-ups. Anxiety and the sense of presence experienced during exposure sessions (secondary outcome measures: VAS-A and VAS-P) will also be assessed. It is expected that participants in the VRET-M group will report a further reduction of FoF-related symptomatology after the treatment and at follow-ups compared to participants in the VRET-B and IET groups. Likewise, participants in the VRET-M group are expected to show higher sense of presence levels during exposure sessions in comparison to participants in the VRET-B and IET groups. It is expected that the IET group will report the lowest level of sense of presence and the poorest outcome after treatment and at follow-ups.

Participants who meet the inclusion criteria will be invited to participate in the initial treatment session. They will be also required to purchase a flight ticket during the six months after the end of the treatment. Participants will be treated weekly for eight individual sessions. While the first two sessions involve preparation and training, exposure will be conducted between the third and eighth session. The exposure sessions' structure and content will be the same in all conditions. Nevertheless, the VRET-M group will experience vibrotactile cues, while the VRET-B group will not. Furthermore, the IET group will experience its own subjective imagined environment without any external stimulation.

Inclusion Criteria:

• Subjects who meet the Diagnostic and Statistical Manual of Mental Disorders (DSM-5, American Psychiatric Association, APA, 2013) criteria for FoF.

Exclusion Criteria:

• Individuals with a diagnosis of panic disorder, obsessive-compulsive disorder, or psychotic disorder who have received psychotherapy for their FoF, have been taking prescribed medication for their FoF, or have experienced cardiorespiratory disease or an epilepsy attack will be excluded from the study.