Competing interests: Daphne Korczak reports funding from the Canadian Institutes of Health Research (CIHR), SickKids Foundation, University of Toronto and Ontario Ministry of Health, and travel support from the Canadian Paediatric Society and the Canadian Academy of Child and Adolescent Psychiatry. She is chair of the Mental Health Task Force with the Canadian Paediatric Society and of the Research and Scientific Program Committee with the Canadian Academy of Child and Adolescent Psychiatry. Clara Westwell-Roper reports funding from the International OCD Foundation, BC Children’s Hospital Research Institute and the University of British Columbia Department of Psychiatry. Roberto Sassi reports funding from CIHR, Juravinski Research Institute and Hamilton Health Sciences, and travel support from the Provincial Health Services Authority. No other competing interests were declared.