3.1.2 Genetics & Addiction Flashcards
what is the genetic explanation useful to explain?
why some people become addicted and others dont
what does the genetic explanation say addicts are?
predisposed to addiction via genetic vulnerabilities
what are first degree relatives (family studies)?
parents
children
siblings
how much genetic similarity do 1st degree relatives show?
50%
what are second degree relatives?
grandparents and grandchildren
how much genetic similarity do second degree relatives show?
25%
what are 3rd degree relatives?
cousins aunties uncles nieces nephews
how much genetic similarity do third degree relatives show?
12.5%
what is the concordance rate?
percentage likelihood of people showing the same behaviours
do genetics predict a positive or negative correlation of people showing the same behaviours as their relatives?
positive
what is a term for identical twins?
monozygotic twins
how much genetic similarity do monozygotic twins show?
100%
if genetic theory is correct what concordance rate would be predicted for addiction between identical twins?
100%
what do adoption studies aim to separate out?
effects of nature and nurture
if genetic theory were correct what concordance rate would we predict for addiction, when biological parents are addicts and the child is adopted and raised in a non addict environment?
still predict a high concordance rate
on the basis of twin studies it has been found genetic factors are involved in what?
a persons susceptibility to addictive substances e.g. alcohol
we inherit different versions in some genes which results in variation in what?
the way some substances are metabolised
Genes can alter levels of what chemicals?
neurotransmitters helping brain cells signal each other
other genes influence aspects of behaviour such as what?
desire for new experiences or risk taking
what might make an individual inherently vulnerable to addiction?
genes life environment susceptibility to substances due to biochemistry behaviour patterns e.g. impulsivity
what is the A1 variant of the DRD2 gene associated with?
addictive behaviours such as smoking, alcoholism and gambling
individuals with the A1 variant of the DRD2 gene have fewer what?
dopamine receptors in the mesolimbic dopamine reward pathway
how do individuals with lower dopamine receptors (DRD2) compensate for it?
overstimulating by engaging in addictive behaviours
what are the ADH & ALDH linked to an increase risk of?
alcoholism
what are the ADH & ALDH genes responsible for the process of?
how alcohol is metabolised by the body
variation of the ADH & ALDH genes means alcohol breakdown is what?
much slower
as alcohol breakdown is slower what are individuals with the ADH and ALDH genes more likely to do more?
drink a lot more and become addicted
