title: Are there common familial influences for major depressive disorder and an overeating-binge eating dimension in both European American and African American female twins?
abstract: OBJECTIVE
  Although prior studies have demonstrated that depression is associated with an overeating-binge eating dimension (OE-BE) phenotypically, little research has investigated whether familial factors contribute to the co-occurrence of these phenotypes, especially in community samples with multiple racial/ethnic groups. We examined the extent to which familial (i.e., genetic and shared environmental) influences overlapped between Major Depressive Disorder (MDD) and OE-BE in a population-based sample and whether these influences were similar across racial/ethnic groups.
  
  
  METHODS
  Participants included 3,226 European American (EA) and 550 African American (AA) young adult women from the Missouri Adolescent Female Twin Study. An adaptation of the Semi-Structured Assessment for the Genetics of Alcoholism (SSAGA) was administered to assess lifetime DSM-IV MDD and OE-BE. Quantitative genetic modeling was used to estimate familial influences between both phenotypes; all models controlled for age.
  
  
  RESULTS
  The best-fitting model, which combined racial/ethnic groups, found that additive genetic influences accounted for 44% (95% CI: 34%, 53%) of the MDD variance and 40% (25%, 54%) for OE-BE, with the remaining variances due to non-shared environmental influences. Genetic overlap was substantial (rg  = .61 [.39, .85]); non-shared environmental influences on MDD and OE-BE overlapped weakly (re  = .26 [.09, .42]).
  
  
  CONCLUSIONS
  Results suggest that common familial influences underlie MDD and OE-BE, and the magnitude of familial influences contributing to the comorbidity between MDD and OE-BE is similar between EA and AA women. If racial/ethnic differences truly exist, then larger sample sizes may be needed to fully elucidate familial risk for comorbid MDD and OE-BE across these groups.
authors.affiliation: Department of Psychiatry, Washington University School of Medicine, St. Louis, Missouri; Midwest Alcoholism Research Center, Washington University School of Medicine, St. Louis, Missouri.
authors.forename: Melissa A
authors.initials: MA
authors.lastname: Munn-Chernoff
authors.forename: Julia D
authors.initials: JD
authors.lastname: Grant
authors.forename: Arpana
authors.initials: A
authors.lastname: Agrawal
authors.forename: Rachel
authors.initials: R
authors.lastname: Koren
authors.forename: Anne L
authors.initials: AL
authors.lastname: Glowinski
authors.forename: Kathleen K
authors.initials: KK
authors.lastname: Bucholz
authors.forename: Pamela A F
authors.initials: PA
authors.lastname: Madden
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Heath
authors.forename: Alexis E
authors.initials: AE
authors.lastname: Duncan
mesh_terms: D000293:Adolescent; D000328:Adult; D001741:Black or African American / Q000208:ethnology / Q000235:genetics / Q000523:psychology; D000437:Alcoholism / Q000208:ethnology / Q000235:genetics / Q000523:psychology; D056912:Binge-Eating Disorder / Q000208:ethnology / Q000235:genetics* / Q000523:psychology; D003865:Major Depressive Disorder / Q000208:ethnology / Q000235:genetics*; D039721:Diagnostic and Statistical Manual of Mental Disorders; D004200:Diseases in Twins / Q000208:ethnology / Q000235:genetics / Q000523:psychology; D004777:Environment; D005260:Female; D006801:Humans; D006963:Hyperphagia / Q000208:ethnology / Q000235:genetics* / Q000523:psychology; D008923:Missouri / Q000208:ethnology; D014427:Twins; D044465:White People / Q000208:ethnology / Q000235:genetics / Q000523:psychology; D055815:Young Adult
keywords: African American; binge eating; major depression; overeating; race/ethnicity; twins