Circulating leptin levels are associated with increased craving to smoke in abstinent smokers

► This study examined leptin's associations with craving for cigarettes and smoking relapse among smokers interested in cessation. ► It was conducted to extend recent evidence suggesting that leptin was associated with increased craving for alcohol. ► High circulating leptin levels were associated with increased craving, withdrawal symptoms, negative affect, physical symptoms, and reduced positive affect. ► The results indicate that circulating leptin is a promising biological marker of craving for smoking and warrant further investigation of the links between appetite regulation and nicotine dependence