The Frederick W. Thompson Anxiety Disorders Centre has experienced significant demand for services related to the treatment of Obsessive Compulsive Disorder (OCD), resulting in a significant wait time for service. Although Cognitive Behavior Therapy (CBT) is the most efficacious treatment intervention for OCD, there is a growing literature indicating the mindfulness based approaches can be beneficial in terms of managing acute mood and anxiety symptoms as well as reducing relapse risk following treatment.The goal of this study is to examine the potential benefits of using a consumer grade EEG-based biofeedback device that allows clients to engage in home based mindfulness meditation practices while they are waiting to receive clinical services. Specifically, this study will investigate the effects of meditation home practice on symptom alleviation, as related to specific OCD related cognitive processes.

The goal of this study is to examine the potential benefits of using a consumer grade EEG-based biofeedback device that allows clients to engage in home based mindfulness meditation practices while they are waiting to receive clinical services. Specifically, this study will investigate the effects of meditation home practice on symptom alleviation, as related to specific OCD related cognitive processes.The study will be a randomized trial where subjects (N=100) will be randomly assigned to receive either 1) an eight week meditation program involving use of an EEG-based biofeedback device, or 2) wait list as per usual. The experimental design is a 2 (treatment condition: Group 1: Mindfulness, Group 2: Control) by 3 (assessment phase: baseline (week 0), mid-treatment (week 4), post-treatment (week 8)) repeated measures factorial design. Group randomization will be completed by the principal investigator, using the "GraphPad Quick Calcs" online calculator which offers simple random allocation into equal-sized groups.Outcome measures will involve ratings of OCD symptom severity, OCD beliefs, mindfulness, and use of thought control strategies. At baseline, mid treatment (session 4), and post intervention, participants will complete the Yale-Brown Obsessive Compulsive Scale, Obsessive Compulsive Inventory, Obsessive Beliefs Questionnaire, Five Factor Mindfulness Questionnaire, Thought Control Questionnaire, Acceptance and Action Questionnaire, Mind Wandering Scale and the Metacognitions Questionnaire. Once per week, participants will complete the YBOCS, TCQ, and MW. This weekly data will be collected online using the "Survey Monkey" web portal. Daily practice data from the EEG headsets will be automatically uploaded to an encrypted server.

Inclusion Criteria:

• All inclusion and exclusion criteria are consistent with the established guidelines for our service - there are no additional study specific criteria. Potential subjects are referred to the service with a query of OCD. Due to the nature of the assessment procedures, which include English-language self-report questionnaires and scales, the ability to communicate in written and spoken English is an inclusion criterion. disorder

Exclusion Criteria:

• Exclusion criteria include a) those with active substance abuse/dependence, b) suspected organic pathology, c) recent suicide attempt/active suicidality, d) active bipolar, psychotic disorder or post-traumatic stress