1 Department of Psychology, Queen's University, Kingston, Canada.
2 Department of Psychology, Concordia University, Montreal, Canada.
3 Department of Psychiatry, Queen's University, Kingston, Canada.
4 Department of Developmental Psychopathology, Radboud University, Nijmegen, The Netherlands.

Objective: Anxiety disorders are the most prevalent form of psychopathology among youth. Because demand for treatment far exceeds availability, there is a need for alternative approaches that are accessible, engaging, and incorporate practice to reach as many youth as possible. MindLight is a novel videogame intervention that combines evidence-based anxiety reduction techniques with neurofeedback mechanics that has been shown to reduce anxiety symptoms in youth. This study examined the effectiveness of MindLight compared with online cognitive behavioral therapy (CBT) to replicate and extend those findings by testing the reduction of reactivity to anxiety-eliciting laboratory stressors. Materials and Methods: A randomized controlled trial was conducted with laboratory assessments at pre-intervention, post-intervention, and 3-month follow-up. Participants were 117 anxious youth (66.7% female, 33.3% male; age range: 8.05-15.93 years) who were randomized into MindLight (n = 56) and CBT (n = 60) conditions. Both interventions were completed in five 1-hour sessions within a 3-week period. At each time point, anxiety symptoms were assessed through self-report, and state anxiety and anxious arousal were measured during laboratory stress tasks. Results: All measures of anxiety significantly decreased over time in both conditions (P < 0.05). Moreover, youth in the MindLight condition showed greater pre-to-post reductions in anxiety symptoms compared with youth in the CBT condition (P < 0.05). Conclusion: Findings demonstrate that the effects of MindLight and online CBT are not only associated with reductions in anxiety symptoms, but also impact how youth react to laboratory stressors in the moment. ClinicalTrials.gov Identifier: NCT02326545.