Virtual reality for research and treatment of psychosis

This thesis reports on two clinical research studies. The first study researched mechanisms of paranoid ideation, including the ecological validity of virtual reality social environments for eliciting paranoid ideations and behavior, and safety of use concerning cybersickness (chapter 2-4). The second study was a randomized controlled trial examining the effects of virtual reality-based cognitive behavioral therapy for paranoid ideations and social functioning (chapter 5-7). Chapter 2 explored mechanisms of paranoid ideation using controlled virtual social environments100. We found both paranoid thoughts and subjective distress increased in congruence with the degree of social stress added to the virtual social environment. Psychosis liability and pre-existing symptoms positively impacted the level of paranoia and distress in response to social stress. These results provide experimental evidence that heightened sensitivity to environmental social stress may play an important role in the onset and course of psychosis. Cognitive biases are associated with psychosis liability and paranoid ideation225. Chapter 3 investigated the moderating relationship between pre-existing self-reported cognitive biases and the occurrence of paranoid ideation in response to different levels of social stress in a virtual reality environment. Results showed an additive effect of separate cognitive biases on paranoid response to social stress. The effect of social environmental stressors on paranoid ideation is enhanced by attention to threat bias and external attribution bias. Cybersickness is a negative side effect of virtual reality exposure and is associated with treatment dropout. Chapter 4 aimed to investigate the occurrence of cybersickness226. A large majority of patients and controls reported at least one symptom of cybersickness after exposure to the virtual reality environment. Interestingly, many of these physical symptoms were already reported before participants were exposure to the virtual reality environment. This study replicated gender differences in cybersickness symptoms. It also replicated findings that a significant correlation between anxiety and cybersickness can be found in healthy individuals, but not in patients. Anxiety partially mediated cybersickness symptoms, particularly nausea and disorientation. Cybersickness symptoms appear to overlap with anxiety symptoms and are therefore expected to decline during treatment. The second study was an intervention study. We developed a virtual reality-based cognitive behavioral therapy for patients with a psychotic disorder, which was assessed in a single-blind multisite randomized controlled trial. Chapter 5 outlines the study protocol developed to investigate the effects of virtual reality-based cognitive behavioral treatment on social participation in real life among patients with a psychotic disorder114. Chapter 6 presents the main results of the clinical trial213. The post-treatment assessment showed that paranoid ideation and anxiety during real-life social situations were significantly reduced in the virtual reality-based cognitive behavioral treatment group compared with the control group, and these improvements were maintained at the follow-up assessment. According to the post-treatment assessment, virtual reality-based cognitive behavioral treatment did not significantly increase the amount of time spent with other people. The virtual reality-CBT group did show significant improvements in self-stigmatization and social functioning at the follow-up assessment, whereas the control group did not. Safety behaviors and social cognition problems were mediators of change in paranoid ideation. No adverse events were reported relating to the therapy or assessments. Chapter 7 demonstrated that offering virtual reality-based cognitive behavioral treatment to patients with paranoid delusions is an economically viable approach for improving the patients’ health in a cost-effective manner227. The mean incremental costs for a treatment responder on social participation ranged between €8,079 and €19,525, with 90.74%-99.74% of participants showing improvement. The average incremental cost per QALY was €48,868 over the six months of follow-up, with 99.98% of participants showing improved QALYs.