—Twenty47studio—Getty ImagesDespite decades of public health campaigns, smoking remains stubbornly persistent. Around 10% of American adults still smoke cigarettes, while millions more use e-cigarettes and other nicotine products. Nicotine is among the most addictive substances known, altering the brain’s reward pathways and making quitting notoriously difficult. Most people who smoke want to stop. Many try repeatedly before they succeed. I firs…