Addiction- biological addiction genes

Question 1

Genes and addiction?

Answer 1

Unlikely that there is a single gene for addiction, its more likely that there are a number of genes that can increase the susceptibility to addiction to various substances or behaviour
-May be difference in addictive behaviour can be explained by genetic make up of individual, perhaps some carry gene that makes them more prone to develop an addiction when consuming a potentially addictive substance or engage in behaviour

Question 2

What are inheritance study?

Answer 2

We can use inheritance studies to investigate the roles genes play
Family studies, twin studies and adoption studies

Question 3

Inheritance study- Prescott and Kendler 1999?

Answer 3

Used personal interviews to assess alchol abuse and dependance among 3,516 twins from male and male pairs born in birginia between 1940s and 74
Concordance rates were much higher between MZ twins when compared to DZ twins
Concluded 48-58% of variance of addiction is genetic

Question 4

Inheritance study- Kendler et al?

Answer 4

conducted a large scale adoption study in Sweden
Cjildren of biological parents or who had genetic full and hald siblings who had drug addiction had a significantly higheer risk of much higher activity
However, they noted that the risk was much higher if there were environmental factors in the adopted family such as criminal activity, divorce, alchol problems or death

Question 5

Inheritance study- Agrawal and Lynskey?

Answer 5

Previous reaserch into the genetic basis of addiction, in particular twin studys
Genetic influence of addiction ranging from 30-70%
However, highlighted importance of interplay between genes and the environment

Question 6

Inheritance study- Winokur et al 1970, Reich et al 1980s and Guze et al 1986?

Answer 6

Many family studies into alchol abuse found there may be some truth to the classic udea of an alcholic family
Data here comes from 3 studies into alcholoc family

Question 7

What are the two genes assoicated by addiction?

Answer 7

DRD2
ADH

Question 8

Gene- what is the DRD2 gene?

Answer 8

Codes with how many amount of receptors you have

Question 9

Gene- DRD2 what is A1?

Answer 9

those with A2 have fewer dopamine receptor sites

Question 10

Gene- how does A1 DRD2 effect behaviour?

Answer 10

Means increased so theres overcopensation on behaviour to get more feelings of pleasure and reward
Try and overstimukate through engaging behaviour

Question 11

Gene- DRD2 comings et al?

Answer 11

Found that 48.7% of smokers and ex smokers carried the A1 gene of DRD2 compared to 25.9% of genral population

Question 12

Gene- DRD2 what does this suggest about A1?

Answer 12

A1 gener can acount for addictive behaviour

Question 13

What do ADH and ALDH genes do?

Answer 13

Responsible for how alchol is metabolised

Question 14

How do ADH and ALDH decrease risk of alcholism?

Answer 14

A fast ADH enzyme and a slow ALDH can cause toxic acetaldehyde to build in the body causing unplesant effectscausig toxic affects of alchol like flushing nausea etc shows why people with this gene are less liekly to have alcoholism

Question 15

ADH gene- why are alchol rates in east asia support this?

Answer 15

Because people from east asia have genes causing them to noot part take in drinking activity
Thus there drinking culture very differet from the west

Question 16

ADH- how do other varients of gene increase alcholism?

Answer 16

People with the ADH gene and arent there and cause alchol to be absorbed and metabolised faster causing no unplesant effect e.g. no hangovers

Question 17

What does the diathesis stress model say?

Answer 17

Its to simplistic to suggest addictions caused by just genetics its important to consider genetic interactions with enviroment, suggesting addiction only occurs when predisposition to disorder is triggered by environmental stress