Table 3:

Working memory, IQ and focused attention as mediators of the relationship between PRS for ADHD and hyperactivity-impulsivity for the White non-Hispanic subpopulation (N = 438). The five levels of ADHD polygenic risk that were associated with hyperactivity-impulsivity were tested across six cognitive domains. Results for associations with impulsivity can be seen in Supplemental Table B6. Results for processing speed, sustained attention and perseverative/impulsive responding as mediators are given in Supplemental Table B7. The percent of the total effect accounted for by the mediation model is given where there was significant cognitive mediation.

		Cognitive Mediators
		Working Memory		IQ		Focused Attention
Symptoms	PRS threshold	β (CI)	p-value [%]	β (CI)	p-value [%]	β (CI)	p-value [%]
Hyperactivity-impulsivity	0.1	0.027 (0.0051 to 0.053)	0.01 [28%]**	0.019 (0.0036 to 0.042)	0.009 [20%]**	0.016 (0.0021 to 0.037)	0.02 [17%]**
	0.2	0.032 (0.0098 to 0.059)	0.002 [31%]**	0.02 (0.0041 to 0.042)	0.008 [19%]**	0.015 (0.0016 to 0.036)	0.02 [14%]*
	0.3	0.026 (0.0043 to 0.052)	0.02 [25%]**	0.02 (0.0038 to 0.042)	0.009 [18%]**	0.015 (0.0013 to 0.035)	0.03 [13%]*
	0.4	0.027 (0.0052 to 0.053)	0.01 [28%]**	0.021 (0.0039 to 0.043)	0.007 [20%]**	0.014 (0.0006 to 0.033)	0.04 [13%]*
	0.5	0.025 (0.0032 to 0.051)	0.03 [24%]*	0.019 (0.0031 to 0.04)	0.01 [17%]**	0.012 (−0.00018 to 0.031)	0.05 [11%]

^*nominal p < 0.05

^**FDR corrected, q < .05