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 .
Dopamine D4 Receptor Gene Variation Moderates the Efficacy of Bupropion for Smoking Cessation
Smokers ( ⩾10 cigarettes per day , N=331 ) of European ancestry taking part in a double-blind placebo-controlled r and omized trial of 12 weeks of treatment with bupropion along with counseling for smoking cessation were genotyped for a variable number of t and em repeats polymorphism in exon III of the dopamine D4 receptor gene . Generalized estimating equations predicting point-prevalence abstinence at end of treatment and 2 , 6 and 12 months after the end of treatment indicated that bupropion ( vs placebo ) predicted increased odds of abstinence . The main effect of Genotype was not significant . A Genotype × Treatment interaction ( P=0.005 ) showed that bupropion predicted increased odds of abstinence in long-allele carriers ( odds ratios (OR)=1.31 , P<0.0001 ) , whereas bupropion was not associated with abstinence among short-allele homozygotes ( OR=1.06 , P=0.23 ) . The Genotype × Treatment interaction remained when controlling for demographic and clinical covariates ( P=0.01 ) and in analyses predicting continuous abstinence ( P's⩽0.054 ) . Bupropion may be more efficacious for smokers who carry the long allele , which is relevant to personalized pharmacogenetic treatment approaches
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 .