Baseline and covariate adjusted mean scores at 18 months for each group and Cohen’s d of the difference in mean score change over 18 months, relative to the Aβ- ε4 non-carrier group.

Abbreviations: DETIDN, Psychomotor/Attention composite; DET, Detection task; IDN, Identification task; OCLOBK, Learning/Working Memory composite; OCL, One Card Learning task; OBK, One Back Learning task; CVLT-II Total, California Verbal Learning Test, Second Edition, total recall; CVLT-II Delay, CVLT-II, 20 minute delayed recall. NOTE. Bolded values are significant at the p < .05 level. Means are adjusted for age, premorbid IQ, levels of anxiety symptoms, and baseline performance.