Genetic Explanation for Depression

  1. What is meant when it is said that mood disorders have a genetic basis?
    Mood disorders are caused by genetic factors and the inheritance of certain alleles
  2. What types of studies are commonly used to show a genetic basis?
    Family studies and twin studies
  3. What is the prevalence of depression in the general population?
    10% for males and 20% for females
  4. What is the prevalence of depression used as?
    A baseline against which the concordance rates of other studies can be compared
  5. What ethnic group did Egeland study and how many of them did he use?
    Egeland studied 81 members of an Amish family
  6. How many members of Egeland's sample group had manic depression?
  7. What is the baseline percentage for people with manic depression?
  8. How many of Egeland's group had serious depression?
  9. Egeland implicated the genes on which chromosome?
  10. What percentage of the amish family studied by Egeland with the faulty gene fell ill?
  11. What did Gershon investigate in 1990?
    10 studies of pro bands with unipolar depression were reviewed
  12. What did Gershon find during his study of 1990?
    Rates of depression for first degree relatives of the proband were between 7% and 30%, much higher than would be found in the general population
  13. Describe the aim of McGuffin et al (1996)
    To investigate the genetic component of unipolar depression
  14. How many people were studied by McGuffin et al?
    177 same sex twin pairs
  15. How many pairs of monozygotic and dizygotic twin pairs were investigated by McGuffin et al?
    68 Monozygotic and 109 Dizygotic
  16. What did McGuffin et als' results show?
    • DZ twins: 20% concordance
    • MZ twins: 46% concordance
  17. How many of the twins in McGuffin et al had depression?
    One from each pair
  18. Why hasn't a gene for mood disorders been discovered?
    There are many different subtypes for depression making identifying a gene very difficult
  19. What did Brown and Harris find in 1987?
    Other social factors such as unemployment, divorce or caring for children may be more important in determining depression
  20. Why is it difficult to determine cause and effect for genetic influences on depression?
    Many twins or families have the same environment or upbringing so there are many other factors that may account for the results
  21. How is the genetic explanation based on indirect evidence?
    When depression runs in families it is attributed to genetics when other factors could be the cause
  22. What did Wilhelm et al suggest in 2006?
    An abnormal serotonin transporter gene could play a crucial role in depression meaning the neurochemical basis for depression may be caused by a faulty gene
Card Set
Genetic Explanation for Depression