Caspi et al 2003 Flashcards
(9 cards)
diathesis stress theory
individuals react to stressful life events differently, based on their genetic makeup
certain people might have the genotype of a particular disorder that will be expressed as a result of the environment and such stressors
aim
To investigate whether a functional change in the 5HTT gene (a seratonin transporter responsible for the intake of seratonin in brain synapses) is linked to a higher or lower risk of depression in an individual, and how it correlates with the environment
5-HTT
seratonin transporter gene responsible for teh uptake of seratonin in the brain synapses
participants
247 26year old new zealanders
- assessed for their mental health regularily once a year until they were 21
- all members of a support group
procedure
- the participants divided into 3 groups, based on their 5-HTT gene
- group 1 had 2 short allele (the mutation)
- group 2 had 1 short 1 long allele
- group 3 had 2 long allele
- the participants were given a questionnaire regarding stressor experiences, where they were asked for the frequency of 14 events
(employment, health, relationship, financial stressors) - assessed for depression
results
participants with the mutated 5 - HTT gene demonstrated much more symptoms of MDD
the effect was the strongest for those with stressful lives, from stressful environments
conslusion
the interaction of genes, in particular 5 - HTT with the environment might cause depression
strengths
- takes a holistic approach
weaknesses
- correlational study (cause and effect cannot be established
- assumes that seratonin is responsibe for depression
- self reported (not as reliable ig)
- low reliability (studies that attempted to recreate it did not show simmilar results)
- some participants who did not carry the gene also became depressed so its impossinle to say that this gene expression ALONE causes depression
