Association of the apolipoprotein E epsilon 4 allele with late-onset depression

Apolipoprotein E (ApoE) phenotyping was determined in 42 subjects with Alzh eimer's disease (AD), 49 with depression, including 26 with early-onset dep ression (EOD) and 23 with late-onset depression (LOD), and 49 controls. In the EOD group, the frequency of the ApoE epsilon4 allele was not different from the control frequency (p = 0.532) but was significantly lower than in AD (p < 0.001). In the LOD group, the ApoE epsilon4 frequency was significa ntly higher than in the controls (p = 0.034) but was not different from tha t in the AD group (p = 0.229). Individuals with ApoE epsilon4 were at great er risk of getting AD (odds ratio, OR = 5.5, 95% confidence interval, CI, 2 .0-14.0) or LOD (OR = 6.1, 95% CI, 1.9-19.0) than of EOD (OR = 0.7, 95% CI, 0.2-2.5). These results suggest an association between the ApoE e4 allele frequency and LOD. Patients with LOD could be at risk of developing AD by a n epsilon4-dependent pathway. Copyright (C) 2001 S. Karger AG. Basel.