Addiction genes

Question 1

Virginia twin study

Answer 1

in early adolescence use of nicotine, alcohol and canibis more strongly determined by familial and social factors. genetic factors become maximal in young/middle adulthood.

Question 2

Goldman

Answer 2

heritability of addictions range from +.39 (hallucinogens) to +.72 (cocaine)

Question 3

comings et al (1996)

Answer 3

25.9% of general population have A1 variant of DRD2. found in 48.7% of smokers and ex smokers and 50.9% of gamblers.

Question 4

Higuchi (2006)

Answer 4

lower activity variants of ADH genes associated with increased risk of alcohol dependence in oriental populations

Question 5

Anton et al

Answer 5

Naltrexone given to people with certain gene mutation more likely to abstain that heavy drinkers without the mutation. different treatments work best on different genes. pharmacogenetics

Question 6

Kendler

Answer 6

Swedish twins born between 1910 and 1958. women born earlier had low heritability of tobacco use, heritability for women born later in study was 60%. changing attitudes of what is acceptable for women had large influence, overtime increased chance of predisposition being expressed. link to diathesis stress

Question 7

Ojelade et al

Answer 7

when Rsu1 gene malfunctioned in fruit fly it had lowered sensitivity to alcohol, brain imaging showed it to also be true in humans with alcohol dependence. potentially more undiscovered genes that could lead to treatment also means there’s no ‘one gene’. different genes interact differently with different substances.

Question 8

CHRNA5

Answer 8

people with two copies of certain form of CHRNA5 2x more likely to be nicotine dependent.