Caspi's study Flashcards
Aim of the study
Aimed to investigate why stressful life events seem to lead to depression in some people and not others. They then investigated whether stressful life events were more likely to lead to depression in people with a certain variation of the 5-HTT gene.
Procedure
Participants were a group of children who had been studied since birth. This was a longitudinal study with each participant completing a questionnaire that measured the life events that occurred between their 21st and 26th birthdays. Another questionnaire assessed whether they had any symptoms of depression in the year before their 26th birthday, which gave the researchers quantitative data in the form of a depression score.
Results
Participants who had at least one short version of the 5-HTT gene and went through stressful life events between 21 and 26 showed an increase in symptoms of depression after the event
Participants with a short version of the gene who experienced a stressful life event were more likely to be diagnosed with depression than those with two long versions of the gene.
Those with a short version of the gene were more likely to develop suicidal thought than those with two long versions
Conclusion
The evidence seems to suggest that there is an interaction between life events and genetic influences in causing depression. This suggests that both nature and nurture work together to increase the likelihood of a person developing depression.
Strengths of the study
There were 847 participants which is a very large sample. This means the results are more generalisable.
Information from this study could be useful for doctors as it tells them that someone with depression could have different causes for their symptoms. Real world applications
Weaknesses of the study
The evidence from the questionnaires is self report data, which might not be reliable. Some may exaggerate their symptoms while others may not make a big deal out of them.
