Is Continued Improvement After Automated Virtual Reality Exposure Therapy for Spider Phobia Explained by Subsequent in-vivo Exposure? A First Test of the Lowered Threshold Hypothesis.

Consumer Virtual Reality (VR) technology offers a powerful, immersive medium for scalable dissemination of mental health interventions. Decades of research has shown VR exposure therapy to be efficacious in the treatment of anxiety disorders and that the fear reduction generalizes to real-world stimuli. Many studies also report continued improvement over time, after discontinuing VR use. The lowered threshold hypothesis states that this continued improvement is moderated by lowering the threshold to conduct subsequent in-vivo exposure. The current study is the first to formally test this hypothesis, using data from a recent trial on automated VR exposure therapy for spider phobia, in which participants (n = 49) were followed for 1 year, completing assessments 1 week, 3 and 12 months post-treatment. The assessment included validated self-report of phobia symptoms, a standardized behavioral approach test featuring a real spider, and a questionnaire for self-reporting frequency of in-vivo exposures since last assessment. Number of in-vivo exposures was found to be independently associated with greater symptom decrease in longitudinal outcome models. In sequential structural equation models, immediate post-treatment symptom reduction was associated with subsequent in-vivo exposures, which in turn was associated with continued symptom reduction. However, this applied only to self-reported phobia symptoms (not behavioral avoidance) and no associations were found past 3 months. Our findings offer preliminary, partial support for the lowered threshold hypothesis, suggesting that VR exposure interventions may benefit from including explicit in-virtuo to in-vivo transitioning components.

Automated virtual reality exposure therapy for spider phobia vs. in-vivo one-session treatment: A randomized non-inferiority trial.

OBJECTIVE: This study compared the efficacy of a technician-assisted single-session virtual reality exposure therapy (VRET) for the treatment of spider phobia featuring low-cost consumer-available hardware and novel automated software to gold-standard in-vivo one-session treatment (OST), using a parallel group randomized non-inferiority design. Method Participants (N = 100) were randomized to VRET and OST arms. Assessors blinded to treatment allocation evaluated participants at pre- and post-treatment as well follow-up (3 and 12 months) using a behavioral approach test (BAT) and self-rated fear of spider, anxiety, depression and quality-of-life scales. A maximum post-treatment difference of 2-points on the BAT qualified as non-inferiority margin. Results Linear mixed models noted large, significant reductions in behavioral avoidance and self-reported fear in both groups at post-treatment, with VRET approaching the strong treatment benefits of OST over time. Non-inferiority was identified at 3- and 12- months follow-up but was significantly worse until 12-months. There was no significant difference on a questionnaire measuring negative effects. Conclusions Automated VRET efficaciously reduced spider phobia symptoms in the short-term and was non-inferior to in-vivo exposure therapy in the long-term. VRET effectiveness trials are warranted to evaluate real-world benefits and non-specific therapeutic factors accruing from the presence of a technician during treatment. ClinicalTrials.gov (NCT02533310).