title: ApoE4 allele is associated with late-life depression: a population-based study.
abstract: OBJECTIVE
  This study aimed to clarify the relationship between the epsilon4 allele and late-life depression, taking into account lipid profile, vascular diseases, and sociodemographics.
  
  
  METHODS
  Using a multilevel stratified random sampling strategy, a total of 500 subjects aged 65 to 74 years were recruited for this cross-sectional study from the official household records of an entire county in southern Taiwan. Depressive symptoms were assessed by the Taiwanese Depression Questionnaire (TDQ). Cognitive function was assessed by the Short Portable Mental Status Questionnaire. Blood samples were collected for the determination of the apolipoprotein E (ApoE) polymorphism and the lipid profile.
  
  
  RESULTS
  A total of 283 subjects (58.7% male, with a mean age of 69.2 +/- 2.7 years) completed all questionnaires and collection of blood samples. Using the chi(2) test, the overall difference for frequency of the presence of the epsilon4 allele was significant among the severe group (TDQ score >18), moderate group (TDQ score 9-18), and mild group (TDQ score <9). The proportion of history of heart disease was significantly higher in the severe group than in the mild or moderate group. Kruskal-Wallis statistics revealed that the mean total and low-density lipoprotein cholesterol levels were significantly higher in the severe group than in the moderate or mild group. With our two-level four-class latent class regression model, the presence of the epsilon4 allele was significantly associated with the severely depressed group as compared to the nondepressed group, adjusting for vascular diseases and lipid profile.
  
  
  CONCLUSIONS
  The ApoE epsilon4 allele may be correlated with severe depression in the elderly through ways other than the "vascular depression" hypothesis.
authors.affiliation: Department of Mental Health, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA.
authors.forename: Yung-Chieh
authors.initials: YC
authors.lastname: Yen
authors.forename: George W
authors.initials: GW
authors.lastname: Rebok
authors.forename: Joseph J
authors.initials: JJ
authors.lastname: Gallo
authors.forename: Ming-Jen
authors.initials: MJ
authors.lastname: Yang
authors.forename: For-Wey
authors.initials: FW
authors.lastname: Lung
authors.forename: Chun-Hua
authors.initials: CH
authors.lastname: Shih
mesh_terms: D000367:Age Factors; D000368:Aged; D000483:Alleles; D053327:Apolipoprotein E4 / Q000235:genetics*; D002318:Cardiovascular Diseases / Q000175:diagnosis / Q000453:epidemiology; D002784:Cholesterol / Q000097:blood; D008076:Cholesterol, HDL / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D003072:Cognition Disorders / Q000175:diagnosis / Q000453:epidemiology; D003625:Data Collection; D003865:Major Depressive Disorder / Q000453:epidemiology / Q000235:genetics*; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics; D006801:Humans; D008297:Male; D008954:Models, Biological; D011569:Psychiatric Status Rating Scales; D012307:Risk Factors; D012494:Sampling Studies; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D013624:Taiwan / Q000453:epidemiology; D014280:Triglycerides / Q000097:blood
chemical_list: D053327:Apolipoprotein E4; D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D014280:Triglycerides; D002784:Cholesterol