1 Département de Psychopédagogie et d'andragogie, Université de Montréal, Montreal, Canada.
2 School of Psychology, University of Ottawa, Ottawa, Canada.
3 Substantive-Methodological Synergy Research Laboratory, Department of Psychology, Concordia University, 7141 Sherbrooke W, Montreal, QC, H4B 1R6, Canada. alexandre.morin@concordia.ca.
4 Substantive-Methodological Synergy Research Laboratory, Department of Psychology, Concordia University, 7141 Sherbrooke W, Montreal, QC, H4B 1R6, Canada.
5 Département de Psychoéducation et de Psychologie, Université du Québec en Outaouais, Saint-Jérome, Canada.
6 School of Education, Western Sydney University, Sydney, Australia.
7 Institute for Positive Psychology and Education, Australian Catholic University, Sydney, Australia.
8 Cyberpsychology Laboratory, Department of Psychoéducation and Psychology, Université du

This study proposes a revision (R) of the Center for Epidemiologic Studies Depression Scale for youth with ID (CESD-ID) in English and French. 346 youth (36.02% girls) with mild (51.26%) and moderate (48.78%) ID (11-22 years; M = 15.69), enrolled in secondary schools in Canada (French-speaking; n = 115), and Australia (English-speaking; n = 231), as well as their parents and teachers, participated in this study. Results support the reliability, factor validity, equivalence (sex, ID level, comorbidities, and country), and convergent validity (with youth-, parent-, and teacher-rated measures of depression, anxiety, and loneliness/social isolation) of the CESD-ID-R. The CESD-ID-R allows youth with ID to provide a reliable and valid assessment of their depressive mood and happiness suitable for epidemiological studies.