Biography

Title

• Clinical Associate Professor, Department of Pediatrics, Université de Montréal Medical School (June 2024-)
• Pediatrician, Division of Adolescent Medicine, CHU Sainte-Justine (August 2019-)

• Master of Public Health, Clinical Effectiveness, Harvard School of Public Health (2019)
• Pediatric Addiction Medicine Fellowship, Boston Children’s Hospital, Harvard medical School (2017-2019)
• Fellowship in Global Journalism, Munk School of Global Affairs, University of Toronto (2016-2017)
• Adolescent Medicine Subspecialty training, Hospital for Sick Children, University of Toronto (2015-2017)
• Residency training, general pediatrics, CHU Sainte-Justine, Université de Montréal (2012-2015)
• Undergraduate medical degree, McGill University (2012)

Dr Chadi’s research focuses on the prevention and treatment of substance use issues in adolescents health as well as on the well-being impacts of gender-affirming care in youth. Dr. Chadi’s work aims to improve clinical practices and drive policy changes to better support gender-diverse youth, as well as those experiencing mental health and/or substance use challenges. His lab employs quantitative, qualitative, and participatory research methods, involving patient partners and community-based collaborators. As codirector of the Mental Health axis at the Observatory for Education and Health (OPES), Dr. Chadi is also interested in population-level administrative data analysis and in evaluating in-person and technology-based interventions to improve the health and wellbeing of adolescents with substance use and mental health issues, including eating disorders. 

• Adolescent risky behaviors
• Substance use disorders
• Gender diversity
• Eating disorders in adolescents
• Adolescent mental health
• Mindfulness-based interventions
• Qualitative and quantitative research
• Healthcare services utilisation
• Public health

Career Summary

Dr. Chadi is a pediatrician and clinician-scientist specialized in adolescent and addiction medicine. He is currently Associate Clinical Professor at Université de Montréal and a Junior 2 Clinical Research Scholar with the Fonds de recherche du Québec. In 2019, he became the first pediatrician in North America to complete a fellowship in pediatric addiction medicine.

As the director of the substance use clinic and co-director and co-founder of the gender diversity Clinique at CHU Sainte-Justine, his clinical activities focus on the prevention and treatment of mental health disorders, including eating disorders and substance use disorders during adolescence as well as on treatment of transgender and non-binary youth.

Dr. Chadi is the author of more than 100 peer-reviewed publications including several position statements on tobacco and vaping for the Canadian Paediatric Society and the Society for Adolescent Health and Medicine. A passionate advocate for the improvement of child and adolescent health, he often appears in regional and national media. 

Laboratory

The CHAD Lab
(Child and Adolescent Development Lab)

Awards and Distinctions

• 2025, Emerging Leader Award, large academic centre, Pediatric Chairs of Canada
• 2025, Prix Professions Santé, Équipe hospitalière multidisciplinaire, clinque de diversité de genre du CHU Sainte-Justine
• 2025, Early Investigator Award, AMERSA
• 2023, Prix de l’excellence en engagement social de la santé du département de pédiatrie de l’Université de Montréal, Département de Pédiatrie, Université de Montréal
• 2022, Victor-Marchessault Advocacy Award, Canadian Paediatric Society
• 2020, Best workshop award, AMERSA Annual meeting
• 2020, DuRant award for statistical rigour, SAHM Annual Meeting
• 2022, Victor-Marchessault Advocacy Award, Canadian Paediatric Society
• 2017-2019, Research in Addiction Medicine Scholar Program, National Institute for Drug Abuse
• 2018, Honorable Mention, Best Presentation, American Society of Addiction Medicine
• 2017, Ruth Fox Scholar, American Society of Addiction Medicine
• 2012, Provincial Leadership Award, Canadian Medical Association
• 2012, Lieutenant-Governor of Quebec Award, McGill University
• 2007-201, Millenium Scholarship Award

Major Financing

• Instituts de recherche en santé du Canada et Fonds de Recherche du Québec (2025-2026) : Pluréalités : Amélioration des soins de santé liés à l’identité de genre chez les jeunes : une recherche-action participative
• Instituts de recherche en santé du Canada (2024-2030) : Efficacité d’une intervention de dépistage et référencement facilité à des ressources de cessation tabagique avec navigateurs de la santé pour des parents avec besoins sociaux non comblés : L’étude randomisée contrôlée CanCEASE
• Fondation de la recherche pédiatrique (2024-2027) : PARLONSMAAT : Étude de cohorte PARticipative LONgitudinale sur les Soins Médicaux Affirmatifs chez les Adolescents Transgenres
• Agence de santé publique du Canada (2024-2027) : Toxicité aiguë associée avec l’utilisation d’opiacés, de stimulants et de sédatifs chez les adolescents : étude longitudinale du Programme canadien de surveillance pédiatrique
• Instituts de Recherche en Santé du Canada (2021-2024) : Application of a brief digital screening tool to address parental and adolescent tobacco and electronic cigarette use in pediatric medical care
• Fondation des étoiles (2021-2024): Évaluation d’un programme de soins ambulatoires intensifs pour adolescent.e.s avec un trouble de la conduite ailmentaire
• Agence de santé publique du Canada (2021-2023) : Vaping Associated Lung Injuries among Canadian Children and Youth: a retrospective analysis of Canadian Hospitalization Data

Presentations

1. N Chadi, TM Sze TM. Vaping associated lung injury in Canadian children and adolescents: a national retrospective study of hospital discharge data, NIDA International Forum, Montreal, QC, 2024 (poster presentation)
2. N Chadi, C Namuhoranye, E Diamant, T Perez, O Drouin. Use of cessation resources and quit attempts among parents and adolescents participating in a pilot randomized control pediatric clinic based smoking and vaping cessation intervention. Association for Multidisciplinary Education and Research in Substance Use and Addiction, Annual meeting, Chicago IL, USA, 2024.
3. N Chadi, J Kelley, V Taillefer, S Marsolais, L Chiniara. Clinical and demographic characteristics of a cohort of children and adolescents followed at an interdisciplinary gender diversity clinic, World Professional Association for Transgender Health meeting 2022, Montréal, QC, 2022 (platform presentation)
4. F Vergunst, H Barry, K Minor, N Chadi. Climate Change and Harmful Substance Use – A Risk Pathway Framework, 84th CPDD Annual meeting, Minneapolis, ND, 2022 (poster presentation)
5. N Chadi. COVID-19 and Adolescent Mental Health: Responding to the “hidden epidemic”, platform presentation (selected abstract), Society for Adolescent Health and Medicine Annual Meeting, Chicago IL, 2021 (selected abstract)
6. N Chadi, F Vergunst , M Orri, C Brousseau-Paradis, N Castellanos-Ryan, JR Séguin, DS Nagin, F Vitaro, RE Tremblay, SM Côté. Long-term Social and Economic Outcomes of Adolescent Poly-substance Use among Canadian Boys from Low-income Backgrounds, AMERSA annual meeting, Washington, DC, 2020 (selected abstract)

Publications

PubMed

1. M Carwana, E Moore, H Shariati, H Samji, N Chadi (2025). Illicit drug toxicity from opioid, stimulant or sedative use in adolescents: results of a Canadian one-time cross-sectional study. Paediatr Child Health. 2025 Apr 1;30(4):320-326. doi: 10.1093/pch/pxae104. PMID: 40756552; PMCID: PMC12316521.
2. N Chadi, L Walker-Harding L; COMMITTEE ON SUBSTANCE USE AND PREVENTION (2024). Nonmedical Use of Controlled Medications by Adolescents and Young Adults: Clinical Report. Pediatrics. 2024 Dec 1;154(6):e2024069298. doi: 10.1542/peds.2024-069298. PMID: 39552240.
3. V Taillefer, J Kelley, S Marsolais, L Chiniara, N Chadi (2023). Expected vs. perceived effects of gender-affirming hormone therapy among transmasculine adolescents. J Pediatr Endocrinol Metab. 2023 Sep 26;36(11):1072-1078. doi: 10.1515/jpem-2023-0119. PMID: 37747085.
4. J Kelley, A Pullen Sansfaçon, MA Gelly, L Chiniara, N Chadi (2022). School Factors Strongly Impact Transgender and Non-Binary Youths' Well-Being. Children (Basel). 2022 Oct 4;9(10):1520. doi: 10.3390/children9101520. PMID: 36291456; PMCID: PMC9599998.
5. G Beaudry, O Drouin, J Gravel, A Smyrnova, A Bender, M Orri, MC Geoffroy, N Chadi (2022). A comparative analysis of pediatric mental health-related emergency department utilization in Montréal, Canada, before and during the COVID-19 pandemic. Ann Gen Psychiatry. 2022 Jun 13;21(1):17. doi: 10.1186/s12991-022-00398-y. PMID: 35698227; PMCID: PMC9191527.
6. S Zutrauen, MT Do, L Ghandour, C Moore-Hepburn, S Beno, SA Richmond, N Chadi (2021). Acute injury or illness related to the inhalation of vaping aerosols among children and adolescents across Canada: A cross-sectional survey of Canadian paediatricians. Paediatr Child Health. 2021 Aug 23;27(1):43-49.
7. N Chadi, MN Ahun, C Laporte, M Boivin, RE Tremblay, SM Côté, M Orri (2021). Pre- and postnatal maternal smoking and offspring smoking trajectories: Evidence from a 20-year birth cohort. Prev Med. 2021 Jun;147:106499.
8. N Chadi, S Levy, LE Wisk, ER Weitzman (2020). Student Experience of School Screening, Brief Intervention, and Referral to Treatment. J Sch Health. 2020 Jun;90(6):431-438.
9. N Chadi, R Schroeder, JW Jensen, S Levy (2019). Association Between Electronic Cigarette Use and Marijuana Use Among Adolescents and Young Adults: A Systematic Review and Meta-analysis. JAMA Pediatr. 2019 Oct 1;173(10):e192574.
10. N Chadi, J Rodean, JJ Earlywine, BT Zima, SM Bagley, S Levy, SE Hadland (2019). Treatment for Nicotine Use Disorder Among Medicaid-Enrolled Adolescents and Young Adults. JAMA Pediatr. 2019 Nov 1;173(11):1103-1105.