How hard quitting is turns out to be partly a metabolic question.
Why this topic Vaping made quitting a live question again for a generation that never smoked.
Counted in Europe PMC, where the title or abstract names both this topic and that rsID. The number is papers, not evidence of a cause.
CHRNA3
Smoking behavior
69 papers →BDNF
Smoking behavior
9 papers →CHRNA5
Lung cancer
8 papers →OPRM1
Opioid receptor sensitivity
7 papers →CYP2A6
Smoking behavior
4 papers →ADH1B
Alcohol metabolism speed
3 papers →DBH
Smoking behavior
3 papers →ALDH2
Alcohol flush reaction
2 papers →FTO
Obesity
1 paper →Europe PMC, title and abstract only, searched for “smoking cessation”, “nicotine dependence”, “smoking initiation” alongside each published rsID. Full text was not counted: it returns every paper with an rsID buried in a supplementary table. Recounted monthly.