[Comment] Reflecting on progress, envisioning the future for research in Down syndrome

Individuals with Down syndrome are at risk for several neurodevelopmental and neurodegenerative conditions that cause cognitive, behavioural, and functional decline across the lifespan.1 Two conditions contributing to these challenges are Down syndrome regression disorder and Down syndrome-related Alzheimer's disease, which manifest at an average age of 17 and 53 years, respectively.1 Although both conditions lead to functional impairments, they differ in their onset, speed of progression, and underlying mechanisms.