TABLE 3.

COMT genotype effects on WM performance. Synthesis of the results of multiple regression analyses performed on the WM measures to identify significant effects of COMT genotype. Models 1, 2, and 3 test for additive, Met dominant, and Val dominant effects of COMT genotype, respectively. Model improvements (ΔR²) are relative to a model that used age and sex only as predictors of WM performance. For each model, the total R², ΔR², and standardized regression coefficients (betas) for each regressor are provided. Significant effects are indicated in bold, and significance values are reported as *:p ≤ .05, **: p < .01.

	VSWM	Backwards digit	Social WM av. RT
Model 1: Age, sex, COMT additive effect
R2	.072*	.037	.064*
ΔR2	.057**	.032*	.006
Age	−.046	−.034	.220*
Sex	.051	−.024	−.064
COMT	–.247**a	–.183*c	.082
Model 2: Age, Sex, Met dominant effect
R2	.041	.022	.059
ΔR2	.026	.017	.001
Age	−.077	−.055	.244**
Sex	.078	−.005	−.077
COMT Met dom.	−.162	−.131	−.038
Model 3: Age, Sex, Val dominant effect
R2	.070*	.032	.085*
ΔR2	.055**	.027	.028*
Age	−.047	−.037	.200*
Sex	.041	−.030	−.044
COMT Val dom.	–.243**b	−.170	.173*d

Notes: a: Effect possibly driven more by males (β_COMT = −.331**) than females (β_COMT = −.157)

^bEffect similar in females (β_COMT = −.253*) and males (β_COMT = −.231)

^cEffect possibly driven more by females (β_COMT = −.207) than males (β_COMT = −.151)

^dEffect possibly driven more by females (β_COMT = .216) than males (β_COMT = .134)