By Peter A. McCullough, MD, MPH

I asked Alter AI about ADHD after many of my patients said their children developed this problem during unnecessary pandemic lockdowns and school closures during 2020 and followed by reckless mRNA vaccination in 2021.

Cui et al. (2026) analyze two decades of population-level data from British Columbia to examine how attention-deficit/hyperactivity disorder (ADHD) diagnosis rates have changed over time, with particular attention to the COVID-19 period. Their central finding is clear and difficult to ignore: ADHD diagnoses did not just continue a gradual upward trend—they surged sharply during and immediately after the pandemic, with especially dramatic increases among adolescents and young adults, particularly females.

Using a large cohort of nearly 2.75 million individuals aged 3 to 29 years between 2003 and 2023, the authors tracked new (incident) ADHD diagnoses based on physician visits, hospital records, and prescriptions. While ADHD incidence had already been rising steadily for years, the post-pandemic period (2021–2023) marked a pronounced acceleration far beyond prior trends. This was not a subtle shift. In several groups, the increase was abrupt and steep, suggesting a structural break rather than a continuation of existing patterns.

Diagnoses didn’t just rise—they surged, with teenage girls and young women at the center of an unprecedented post-pandemic spike