For clarity of presentation, cases of schizophrenia, bipolar disorder, or intellectual development disorder are excluded (“ADHD-1” is thus excluded, as it includes those cases. ADHD-2 is just ADHD-1 with those rule out cases removed). The black bar represents the non-ADHD youth; the yellow is ADHD-Tier 2; the red is ADHD Tier 3, and the blue is ADHD Tier 4. The values graphed here represent the standardized mean within each group for General Ability, Executive Function, and Learning/Memory. WISV-V Matrix reasoning is the total scaled score. PRS is polygenic risk for ADHD computed by the LD-pred method (see Methods).