BIOLOGICAL MODELS OF ADDICTION
THE GENETIC MODEL OF ADDICTION
AO1-
INITIATION
The D₂ dopamine receptor gene (DRD₂) was linked to severe alcoholism.
Individuals with the A1 variant of this gene appeared to have significantly fewer dopamine
receptors in the pleasure centres of the brain.
People who inherit the A1 variant of this gene are more likely to become addicted to drugs that
increase dopamine levels as this compensates for the deficiency by stimulating what few
dopamine receptors they do have.
MAINTENANCE
The addiction is maintained because it is only with the drug that they can feel good.
RELAPSE
The individual may relapse if the few dopamine receptors they have (which appears to be a
characteristic of inheriting the A1 variant of the DRD₂ gene) are not sufficiently stimulated –
they may take the drug again to increase dopamine levels.
↓
AO2 –
RESEARCH – Noble (1998)
POINT – supports the link between the A1 variant of the DRD₂ gene and addiction.
EVIDENCE – meta-analysis – found 48% of severe alcoholics, 32% of less severe
alcoholics + 16% of controls (non-alcoholics/drug-abusers) carried the A1 variant of
the DRD₂ gene.
EXPALIN – supports because it shows how those with addictions are more likely to
have this variant of the gene.
EVALUATE – strength – meta-analysis – big sample size – possibly increases
population validity + so increases generalisability of findings beyond the study –
↓
APPROACH – biological
STATE – takes the biological approach to psychology.
EXPLAIN – this approach explains behaviour by relating it to the functioning of the brain.
Argue chemical processes in the brain have an important influence on behaviour.
RELATE – takes this approach because it explains addiction as being the result of a gene
that causes the individual to have fewer dopamine receptors, so they may seek drugs to
stimulate the few dopamine receptors they do have, which can result in an addiction to
that substance.
EVALUATE – weakness – this approach underplays the role of social factors such as
socialisation and cultural influences – so may miss important contributing factors to
THE GENETIC MODEL OF ADDICTION
AO1-
INITIATION
The D₂ dopamine receptor gene (DRD₂) was linked to severe alcoholism.
Individuals with the A1 variant of this gene appeared to have significantly fewer dopamine
receptors in the pleasure centres of the brain.
People who inherit the A1 variant of this gene are more likely to become addicted to drugs that
increase dopamine levels as this compensates for the deficiency by stimulating what few
dopamine receptors they do have.
MAINTENANCE
The addiction is maintained because it is only with the drug that they can feel good.
RELAPSE
The individual may relapse if the few dopamine receptors they have (which appears to be a
characteristic of inheriting the A1 variant of the DRD₂ gene) are not sufficiently stimulated –
they may take the drug again to increase dopamine levels.
↓
AO2 –
RESEARCH – Noble (1998)
POINT – supports the link between the A1 variant of the DRD₂ gene and addiction.
EVIDENCE – meta-analysis – found 48% of severe alcoholics, 32% of less severe
alcoholics + 16% of controls (non-alcoholics/drug-abusers) carried the A1 variant of
the DRD₂ gene.
EXPALIN – supports because it shows how those with addictions are more likely to
have this variant of the gene.
EVALUATE – strength – meta-analysis – big sample size – possibly increases
population validity + so increases generalisability of findings beyond the study –
↓
APPROACH – biological
STATE – takes the biological approach to psychology.
EXPLAIN – this approach explains behaviour by relating it to the functioning of the brain.
Argue chemical processes in the brain have an important influence on behaviour.
RELATE – takes this approach because it explains addiction as being the result of a gene
that causes the individual to have fewer dopamine receptors, so they may seek drugs to
stimulate the few dopamine receptors they do have, which can result in an addiction to
that substance.
EVALUATE – weakness – this approach underplays the role of social factors such as
socialisation and cultural influences – so may miss important contributing factors to
