Results : We confirmed the importance of the 4 main factors influencing SC : ( 1 ) environmental factors , ( 2 ) genomic factors , ( 3 ) gene-environment interactions , and ( 4 ) evidence -based interventions .
The model demonstrates the complex network of factors influencing SC .
Background : Smoking behaviour is a major public health problem worldwide .
Several sources have confirmed the implication of genomic factors in smoking behaviour .
These factors interact both with environmental factors and interventions to develop a certain behaviour .
Objectives : Describing the environmental and genomic factors as well as the interventions influencing smoking cessation  ( SC ) and developing a working model incorporating the different factors influencing SC were our main objectives .
Pharmacogenetic investigation of smoking cessation treatment.
Despite the efficacy of bupropion for smoking cessation , smokers exhibit variability in treatment outcome . The CYP2B6 gene has been implicated in bupropion kinetics and nicotine metabolism , and is a plausible c and i date for pharmacogenetic studies of treatment response . We investigated whether a functional genetic polymorphism in the CYP2B6 gene predicts smoking outcomes in a placebo-controlled r and omized trial . Four hundred and twenty-six smokers of European Caucasian ancestry provided blood sample s and received bupropion ( 300 mg/day for 10 weeks ) or placebo , plus counseling .  Smoking status , abstinence symptoms and side-effects were recorded weekly , and smoking status was verified at the end of treatment and at 6-month follow-up . Smokers with a decreased activity variant of CYP2B6 reported greater increases in cravings for cigarettes following the target quit date and had higher relapse rates . These effects were modified by a significant gender x genotype x treatment interaction , suggesting that bupropion attenuated the effects of genotype among female smokers . We conclude that smokers with the CYP2B6 variant may be more vulnerable to abstinence symptoms and relapse .  Bupropion may attenuate these effects , especially among females . Additional trials are warranted to confirm these results , as are studies to explore the neurobiological mechanisms . Such research could ultimately enable practitioners to select the optimal type and dose of medication for individual smokers
Results : We confirmed the importance of the 4 main factors influencing SC : ( 1 ) environmental factors , ( 2 ) genomic factors , ( 3 ) gene-environment interactions , and ( 4 ) evidence -based interventions .
The model demonstrates the complex network of factors influencing SC .
Background : Smoking behaviour is a major public health problem worldwide .
Several sources have confirmed the implication of genomic factors in smoking behaviour .
These factors interact both with environmental factors and interventions to develop a certain behaviour .
Objectives : Describing the environmental and genomic factors as well as the interventions influencing smoking cessation  ( SC ) and developing a working model incorporating the different factors influencing SC were our main objectives .