APOE = Apolipoprotein E genotype, investigated (+) or not investigated (-); TA = telomerase activity, investigated (+) or not investigated (-);∈3 &∈4 = APOE alleles; MDD = Major Depressive Disorder;a = Age was not given for imaging subsample, age for whole healthy subsample substituted;b = Median and interquartile range. The gene discussed is APOE; the disease is major depressive disorder.