Genetic and environmental influences on depressive symptoms by age and gender in African American twins.


Journal Article

Depression is typically considered relative to individuals and thought to originate from both biological and environmental factors. However, the environmental constraints and insults that African Americans experience likely influence the concordance by age and gender for depression scores among adult African American twins. Monozygotic (MZ) (n = 102) and Dizygotic (DZ) (n = 110) twins, age 25-88 years in the Carolina African American Twin Study of Aging were examined using an 11-item version of the CES-D measure of depressive symptomatology. Those participants with scores above nine were considered depressed. Overall, the MZ pairs had a higher concordance than the DZ pairs implying genetic influence. Both MZ and DZ males had higher concordances than either female zygosity groups. The difference between the concordance rates for MZ and DZ twin pairs was greater in males than females. By age group, the difference between the concordance rates for younger MZ and DZ twin pairs was much larger than for older pairs. The results suggest that, even though African Americans may be at risk for depression due to contextual/environmental factors, genetic influences remain important.

Full Text

Cited Authors

  • Whitfield, KE; Edwards, CL; Brandon, D; McDougald, C

Published Date

  • March 2008

Published In

Volume / Issue

  • 12 / 2

Start / End Page

  • 221 - 227

PubMed ID

  • 18389402

Pubmed Central ID

  • 18389402

Electronic International Standard Serial Number (EISSN)

  • 1364-6915

International Standard Serial Number (ISSN)

  • 1360-7863

Digital Object Identifier (DOI)

  • 10.1080/13607860801951820


  • eng