1. Child and Adolescent Neuropsychiatry, Dipartimento di Scienze Mediche e Pediatriche, University of Catania, Italy
2. Department of Clinical and Health Psychology, Utrecht University/Altrecht Academic Anxiety Outpatient Services, Utrecht, the Netherlands
3. Department of Pediatrics and Pediatric Emergency, Azienda Ospedaliera-Universitaria O.V.E. Policlinico, University of Catania, Catania, Italy
4. Department of Neurology, University Medical Centre Groningen, Groningen, the Netherlands
5. Department of Neurology, St Georges Hospital, University of London, London, United Kingdom
6. Department of Mental Health Sciences, St Georges Medical School, University of London, London, United Kingdom
7. Department of Mental Health Sciences, University College London, London, United Kingdom
8. Department of Psychiatry, University of Cape Town, Rondebosch, Cape Town, South Africa