biological etiolgoies

Question 1

Caspi aim

Answer 1

To determine whether there is evidence for a gene environment interaction for a mutation of the serotonin transporter gene -5-HTT. Serotonin transporter is involved in getting serotonin to the brain.

Question 2

capsi participants

Answer 2

• 847 new zealand 26 year olds\

Question 3

caspi procedure

Answer 3

• All members has been on an every 2 year assessment for mental health till 21
• 3 groups: 1, two short alleles 2, one short one long allele 3, two long allele of 5-HTT.
• Mutation of 5 HTT is shorter which about 43%of people have

Given a ‘stressful life questionnaire’ about 14 events between 21 and 25
14 Events: financial, employment, health, relationship, stressors

Question 4

results caspi

Answer 4

• People who inherited one or more short 5 HTT had more depressive symptoms and suicidal thoughts from stress
• Effect was strongest for 3= stressful events
• Inheriting one gene was not enough to lead to depression but more likely with stressful events

(Wihlem 2006 looked at the DNA of 127 part of a long study25 years looking at mental health. Every 5 years life events and signs of MDD are recorded. Those with two short 5 HTT things became depressed after 3 negative life events though long genes were more resist)

Question 5

strengths caspi

Answer 5

hollistic - looks at a mixture of factors

Question 6

weaknesses caspi

Answer 6

• Correlational no cause and effect can be identified
• Self reported so those who have salience of negative events can cause them more depression.
  Those that can’t recall neg events may be more reliable
• The study is not reliable, its re test was failed
• Does not confirm the use of 5 HTT for depression cuz some people have it and they are fine.

Question 7

kendler aim

Answer 7

• Past studies show 35-45% heritability of mdd, is this true for a large swedish sample?
• Are there gender differences in heritability
• Is there evidence that genetics and environmental factors on mdd differ over time?

Question 8

participants kendler

Answer 8

15,493 twin pairs from swedish twin registry with verified zygosity (mz=identical dz
=none identical)

Question 9

procedure kendler

Answer 9

• Trained interviewers to do telephone interviews
• March 1998-2003
• Interviewers assessed lifetime MDD by using DSM-4 crit
• 8,056 met the crit for MDD at some point and 322 has previous MDD treatment
• They were also asked about shared environment as children and individual specific environments as adults

Question 10

results kendler

Answer 10

• concordance is highest between females
• highest for male and femlae monozygotic (identical)
• years and such didnt influence
• heridibility of 0.38 alighs with past research
• • different chorots didint differ

Question 11

conclusion kendler

Answer 11

The study suggests both that heritability of MDD is higher for women, and some genetic risk factors are sex specfic. Confirmslevels of heritability with other studies therefore europen twins are reliable.

Question 12

strentghs kendler

Answer 12

• large sample
• twin study
• agrees with old research increasing reliability

Question 13

weknesses kendler

Answer 13

• no cause and effect
• no specific gene is identified
• relied on self report wich could differ between men and women
• no official diagnosis made

Question 14

weissman aim

Answer 14

to study genetic nature of MDD

Question 15

participant and style weissman

Answer 15

Longitudinal family study
- 161 grandchildren, parents, grandparents
20 years long
- The original depressed patients were taken from outpatient clinic that dealt with mood disorders

Question 16

procedure of weissman

Answer 16

-
- None depressed taken from same community
-Original parents and children interviewed 4 times in 20 years
- Clinicians that collected data were blind to past interviews and past MDD diagnosis
- Researcher triangulation used.
- children done by one psychologist and one psychiatrist
- Their reliabilities were 0.82 for mdd, 0.65 for anxiety 0.94 for alcohol disorders

Question 17

results weissman

Answer 17

• Children with two generations above of MDD had high rates of psychiatric disorders
  12 years, 59.2%
• Children with non depressed parents less likely to develop
• Severity of depression in parents plays a role
• If parents were depressed, yet not grandparents, no significant effect on grandchildren

Question 18

conclusion weissman

Answer 18

To conclude this study suggests that two generations of MDD will be highly impactful on psychiatric disorders in kids, therefore representing that genetics does in fact play a role in development of MDD

Question 19

weaknesses weissman

Answer 19

• Amount of time spent between grandparents and grandchildren may be a confounding variable
• Large sample so data may not be reliable
• Lack of genotype specified just a potential link

Question 20

strenghths weissman

Answer 20

• longitudinal
• research triangulation
• large sample