-Specific genes can be linked to addiction
-Different people have different versions of the gene that controls dopamine receptors
-If inherited, may be more likely to develop an addiction although a trigger is needed (diathesis stress model)
-These people are more vulnerable at the initiation and relapse stage
-Main way to investigate genetic factors are twin studies
-Recently made possible to carry out genetic analysis
-Family studies tent to illustrate environmental factors in the development of addiction.
MZ = Monozygotic twins (100% genes shared) DZ= Dyzygotic twins (50% genes shared)
Concordance rates between twins = rate at which trait is present/absent in both twins.
Twin studies compare concordance rates of MZ with DZ twins. If a characteristic is present in one MZ twin then it should be present in the other as virtually genetically identical. Concordance rates suggest the extent to…