APOE and major depressive disorder: Moreover, we further compared the baseline characteristics of participants with (n = 344) and without (n = 1,274) MRI, and the analysis showed no significant differences between the 2 groups in terms of sex, education, BMI, alcohol consumption, smoking, hypertension, diabetes, heart disease, stroke, depression, or APOE ε4 carrier status (all p > 0.05) (eTable 1, links.lww.com/WNL/D98).