Despite similar genetic risks, ADHD is disproportionately diagnosed in boys, leaving many girls undiagnosed and struggling without support. Harper Walton-Mouw explores the biases in ADHD diagnosis, particularly how inattentive symptoms in girls—such as daydreaming and restlessness—are often overlooked by parents, teachers, and clinicians. The article examines how outdated diagnostic criteria, based on predominantly male studies, contribute to this gap and discusses potential solutions, including increased clinical awareness and sex-specific diagnostic thresholds. Addressing these disparities is crucial to ensuring timely and effective treatment for all individuals with ADHD.