gene x environment interactions

Question 1

diathesis stress model

Answer 1

idea that negative psychological outcomes result from the interaction between
- a genetic predisposition (diathesis)
- stressful life events (stress)

means that when an individual with a predisposition encounters a stressful life event, they are more likely to develop negative psychological outcomes than those without this predisposition

Question 2

serotonin transporter (5-HTT) Gene

Answer 2

gene that codes for the serotonin transporter, which removes serotonin released into the synaptic cleft (serotonin reuptake)

Question 3

serotonin

Answer 3

neurotransmitter involved in the modulation of emotions

Question 4

5 HTTLPR

Answer 4

region of the serotonin transporter gene that regulates transcription of the gene

Question 5

short allele vs long allele in 5-HTTLPR

Answer 5

short (s) allele: lower efficient transporter function - serotonin remains in the synapse longer, is recycled more slowly, resulting in a net reduction in circulating serotonin

long (l) allele: most common; higher efficiency causing more serotonin reuptake and less extracellular serotonin - ultimately leads to more circulating serotonin

Question 6

5 HTTLPR Life Events and Depression

Answer 6

5-HTTLPR moderates effect of life events on depression

people with one or more of the short allele (s) showed more symptoms of depression and greater suicidality following stressful life events vs those with 2 copies of the long allele

Question 7

differential susceptibility model

Answer 7

some individuals are more biologically susceptible/sensitive to both negative and positive environmental conditions

not that genes make someone more “vulnerable” but instead make them more “malleable” and “reactive” to the environment
so more positive outcomes in response to positive events and more negative outcomes in response to negative events

Question 8

what are the strengths of differential susceptibility model?

Answer 8

• more complete by examining what happens under positive circumstances (greater reactivity/malleability extends to positive circumstances)
• from evolutionary perspective, explains why “risk” genes would have persisted across human history

Question 9

dot probe task

Answer 9

short allele associated with attentional bias for emotional info

Question 10

5-HTTLPR and emotion processing

Answer 10

short allele associated with:
-attentional bias for emotional info
-more activation in brain areas associated with emotion processing(amygdala, prefrontal cortex)

differences in emotional processing and regulation may be mechanism responsible for short allele as susceptibility factor

Question 11

malleability genes

Answer 11

DRD4: dopamine receptor gene
- dopamine system is involved in motivation and reward processing
- 7 repeat allele associated with lower dopamine receptor efficiency

applies DRD4 and maternal sensitivity - externalizing behaviour in insensitive vs highly sensitive parenting