GENETIC EXPLANATIONS FOR MOOD AFFECTIVE DISORDERS

Question 1

What is the genetic explanation for depression?

Answer 1

• Depression is inherited through genes,
• Meaning individuals with a family history of depression are more likely to develop it.
• Studies on twins and first-degree relatives demonstrate that there is higher concordance rates in thoes who share more genetic material.

Question 2

What are concordance rates?

Answer 2

• The likelihood that if one person in a pair (twins/siblings) has a condition, the other will have it.

Higher concordance rates in identical twins suggests a genetic influence of depression.

Question 3

What is heritability?

Answer 3

• The extent to which a trait is inherited (expressed as a %)

Expressed as a %= showing how much genetics contribute compared to the enviroment.

Question 4

What percentage of DNA do first-degree relatives (parents and siblings) share?

Answer 4

50%

Question 5

How do genetic explanations account for mental disorders like depression?

Answer 5

• Mental disorders may have a genetic basis
• and could be transmitted from one generation to the next.

Question 6

What does research suggest about the inheritance of depressive and bipolar disorders?

Answer 6

• Research indicates that these disorders may be inherited.

Question 7

What did McGuffin et al. (1996) study, and what was the sample size?

Answer 7

• McGuffin et al (1996) examined 214 twin pairs where at least one twin was being treated for depression.

Question 8

Sample size- McGuffin et al (1996)?

Answer 8

• 214 twin pairs

Question 9

What was the concordance rate for depression in MZ (identical) twins in McGuffin et al.’s (1996) study?

Answer 9

• 46%.

Question 10

What was the concordance rate for depression in DZ (fraternal) twins in McGuffin et al.’s (1996) study?

Answer 10

• 20%

Question 11

Why is the concordance rate in MZ twins not 100%?

Answer 11

• This suggests that environmental/nurture factors also play a role in depression.

Question 12

What does the difference in concordance rates between MZ and DZ twins suggest?

Answer 12

• There IS a genetic component in depression, as MZ twins (who share 100% of their DNA) have a higher concordance than DZ twins (who share 50%).

Question 13

What are first-degree relatives?

Answer 13

• Close family members (parents, siblings, and children) who share about 50% of their DNA.

Question 14

What was the aim of McGuffin et al. (1996) study on identical twins and depression?

Answer 14

• To investigate the genetic influence on depression by comparing concordance rates in monozygotic (MZ) and dizygotic (DZ) twins.