DRD2-related TaqIA polymorphism modulates motivation to smoke.
BACKGROUND
TaqIA polymorphism, a genetic variant associated with the expression level of dopamine D2 receptors in the brain, has been linked to various aspects of smoking behavior, including smoking prevalence, affective withdrawal symptoms, and smoking cessation outcome. However, its involvement in motivation to smoke cigarettes has not been elucidated.


METHODS
The present study examined the possible differences in self-reported reasons to smoke and craving for smoking in 160 smokers participating in a clinical trial.


RESULTS
Individuals with at least one A1 allele of the TaqIA polymorphism were more likely to report smoking for stimulating effects and to reduce negative affect compared with those lacking an A1 allele. The association of the A1 genotype with a higher probability and stronger motive to smoker to enhance cognitive functioning was evident in female but not in male smokers. Female A1 carriers also expected a greater likelihood of smoking for pleasure than those without an A1 allele. A1 subjects reported stronger craving for cigarettes during early days and the last phase of a 6-week abstinence period.


CONCLUSIONS
These results support the idea that dopaminergic transmission plays an important role in the neurobiological basis of reasons for smoking and that the TaqIA variant is one of the genetic factors underlying individual differences in these aspects. These findings also have implications for improving treatment strategies to help individuals quit smoking by controlling their motivation to continue cigarette consumption.
Zuo
Yantao
Y
Department of Psychology, Southern Illinois University-Carbondale, IL, USA.
Gilbert
David G
DG
Rabinovich
Norka E
NE
Riise
Hege
H
Needham
Rachel
R
Huggenvik
Jodi I
JI
D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics; D005838:Genotype; D006801:Humans; D008297:Male; D009042:Motivation / Q000235:genetics; D011110:Polymorphism, Genetic / Q000235:genetics*; D017448:Receptors, Dopamine D2 / Q000235:genetics*; D012907:Smoking / Q000235:genetics*; D011795:Surveys and Questionnaires
D017448:Receptors, Dopamine D2