title: ApoE alleles, depression and positive affect in multiple sclerosis.
abstract: BACKGROUND
  The role of apolipoprotein E (ApoE) alleles has received recent attention in depressive disorders, the ApoE epsilon4 conferring greater risk for poorer outcomes, and the ApoE epsilon2 allele providing some protective effects. Depression is common in multiple sclerosis (MS) and the role of ApoE alleles is unknown.
  
  
  OBJECTIVE
  To evaluate ApoE alleles in relation to symptoms of depression in a cohort of patients with MS participating in the Sonya Slifka Longitudinal Multiple Sclerosis Study (Slifka Study). To examine risk and protection, depressed mood and positive affect were each investigated with respect to the ApoE epsilon4 and ApoE epsilon2 alleles, respectively.
  
  
  RESULTS
  Of the total 101 participants, 22.8% were ApoE epsilon2 carriers and 21.8% were ApoE epsilon4 carriers. Hierarchical linear regression analyses suggested that after controlling for demographics, disease duration, and disability, ApoE epsilon2 significantly predicted increased positive affect (R2Delta=0.05, F(1,94)=5.44, P=0.02) and was associated with decreased severity of depressive symptoms, although this did not reach statistical significance (R2Delta=0.03, F(1,94)=3.44, P=0.06). ApoE epsilon4 did not significantly predict depression status.
  
  
  CONCLUSIONS
  The presence of the ApoE epsilon2 allele in this study is suggested to be protective against depressive symptoms in our subsample of patients recruited from the Slifka Study. These findings are consistent with reports in psychiatric populations linking ApoE epsilon2 with decreased incidence of depressive disorders. Further investigation would be warranted to understand the role of ApoE genotypes and risk for depressive symptoms.
authors.affiliation: Department of Medicine, University of California San Francisco, San Francisco, CA, USA. laura.julian@ucsf.edu
authors.forename: L J
authors.initials: LJ
authors.lastname: Julian
authors.forename: L
authors.initials: L
authors.lastname: Vella
authors.forename: D
authors.initials: D
authors.lastname: Frankel
authors.forename: S L
authors.initials: SL
authors.lastname: Minden
authors.forename: J R
authors.initials: JR
authors.lastname: Oksenberg
authors.forename: D C
authors.initials: DC
authors.lastname: Mohr
mesh_terms: D000328:Adult; D000483:Alleles; D053329:Apolipoprotein E2 / Q000235:genetics*; D053327:Apolipoprotein E4 / Q000235:genetics*; D003863:Depression / Q000453:epidemiology* / Q000235:genetics*; D004185:Disability Evaluation; D005260:Female; D020022:Genetic Predisposition to Disease / Q000453:epidemiology; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000453:epidemiology* / Q000235:genetics* / Q000523:psychology; D011788:Quality of Life; D012044:Regression Analysis; D012307:Risk Factors
chemical_list: D053329:Apolipoprotein E2; D053327:Apolipoprotein E4