Neural correlates of symptom provocation in pediatric obsessive-compulsive disorder (OCD)

Pediatric obsessive-compulsive disorder (OCD) is a neuropsychiatric illness that has a 1-4 percent prevalence rate in children and youth. OCD is characterized by intrusive thoughts and repetitive behaviours, and although treatments, such as cognitive behavioural therapy (CBT), are available, better treatment selection could improve response rates.

To advance our understanding of the dysfunctional brain mechanisms underlying OCD, and eventually find predictive biomarkers of treatment response, functional magnetic resonance imaging (fMRI) has been used to find the neural correlates of OCD, particularly during symptom provocation tasks (i.e. tasks that allow researchers to probe the brain areas involved in emotional processing by exposing OCD patients to OCD-related stimuli). This research has given us neural correlates of OCD, but fMRI is expensive to implement in clinics.

The goal of this proposal is to use electroencephalography (EEG) to study OCD symptom provocation because it is less costly than fMRI and easily implemented in clinics. EEG also provides an innovative way to investigate OCD, as it provides a fine-grained temporal measure of brain activity, whereas fMRI provides a fine-grained spatial measure of brain activity. Thus, EEG could provide a new set of temporal psychophysiological correlates of OCD that would be easily and inexpensively collected in clinics, and that could predict CBT outcome. In the proposed study, clinically diagnosed pediatric OCD patients (12-18 years old), siblings unaffected by OCD (12-18 years), and matched healthy controls (HCs) will complete an OCD symptom provocation task that elicits emotional responses while EEG is recorded. Event-related potentials (ERPs) will then be derived from the EEG data and will be used to characterize the OCD group in comparison to the sibling and HC group, and to use as potential predictors of CBT response.

The proposed study is novel because few EEG studies of OCD symptom provocation exist, and no emotional-related ERP studies have been conducted in children, although pediatric studies are essential to our understanding of early brain differences.

Our findings will be presented to clinicians and researchers at annual conferences and published in leading peer-reviewed journals. Lay-friendly articles will also be written and submitted to the Canadian OCD Network’s and the International OCD Foundation’s newsletters.