Grant: DRA : Canada Graduate Research Scholarship - Doctoral Program (CGRS D)

Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental condition marked by persistent difficulties with attention, hyperactivity, and impulsivity. It affects 5-12% of children and, without effective treatment, can negatively impact self-esteem and social functioning. ADHD is commonly divided into three symptom-based subtypes: predominantly inattentive (ADHD-I), predominantly hyperactive-impulsive (ADHD-HI), and combined (ADHD-C). However, this symptom-based approach does not fully reflect underlying brain mechanisms. Treatment responses also vary among children, and predicting outcomes based solely on symptoms is insufficient, as similar symptoms may arise from different brain mechanisms, and the same mechanism may produce different symptoms. In my research, I aim to identify brain-based subtypes of ADHD in children using functional magnetic resonance imaging (fMRI). I will leverage the large-scale Healthy Brain Network (HBN) dataset, which includes fMRI data from approximately 2,600 children with ADHD and 370 neurotypical children who watched an engaging movie during scanning. I will develop a novel version of constrained principal component analysis for fMRI to characterize whole-brain activity patterns and determine how these patterns are altered in children with ADHD. I will then apply cluster analysis to identify brain-based subtypes and incorporate phenotypic measures, such as biological sex, to account for individual variability. Through this work, I aim to provide new insights into the brain-based mechanisms underlying ADHD in children, to contribute to the development of more targeted interventions and advancement toward precision psychiatry.