Caspi et al (2003)

Question 1

When did this study take place?

Answer 1

2003

Question 2

What were the aims of this study?

Answer 2

To investigate whether stressful events are more likely to cause depression in those with a certain variation of the 5-HTT gene`

Question 3

What is the significane of the 5-HTT gene?

Answer 3

Linked to availability of serotonin in brain

Question 4

What were the procedures used?

Answer 4

1. 847 ppts
2. Longitudinal study - same ppl tested over a period of time
3. Questionnaire about life events between 21st and 26th bday involving problems with money, health and relationships
4. Questionnaire about experience of depression symptoms before 26th bday
   
   • quantitative data in the form of a depression score

Question 5

What were the results?

Answer 5

At least 1 short gene and after stressful live event = significant increase in incidence, severity and likeliness of depression symptoms than those with 2 long copies

Question 6

What were the conclusions?

Answer 6

1. May be a link between live events and genes in increasing likelihood of depression
2. Ppl may require both the specific gene and a stressful life event to develop depression

Question 7

What are the strengths of this study?

Answer 7

1. Large sample
   - Increases generalisability
2. Has practical applications
   - Encourages investigation of wider variety of depression-causing factors
   - Helps understand why some get depressed and others don’t

Question 8

What are the weaknesses of this study?

Answer 8

1. Some may be more likely to put themselves into situations where stressful events occur
   - Short version of gene could instead increase proneness to these events
2. Self-report data may not be reliable
   - Some may exaggerate or downplay symptoms