CSF cortisol levels were significantly higher in subjects with AD compared to the control group (p<0.01).In the evaluation according to ApoE genotype, the difference in CSF cortisol was significant in ApoE ε4 carriers (p<0.05) but not in ApoE ε4 non-carriers (p=0.25).Subjects with AD and at least one ApoE-ε4 allele exhibited higher CSF cortisol levels compared to AD patients without ApoE ε4 alleles. Here, APOE is linked to Alzheimer disease.