Important methodological note: ADHD diagnosis rates are significantly influenced by evolving diagnostic criteria (DSM-III 1980 → DSM-IV 1994 → DSM-5 2013), growing clinical awareness, and improved access to assessment services — particularly in the UK where ADHD services were historically under-resourced. These factors independently drive measured prevalence upward. The correlation with insulin resistance does not imply causation. However, emerging research does link metabolic dysfunction and neuroinflammation to neurodevelopmental conditions, and the parallel rise across both countries warrants serious scientific attention.