Non-treatment-seeking smokers (n=169) were recruited from the New Haven, Connecticut area for a laboratory study examining factors that moderate nicotine withdrawal and reward. Subjects from this population have been included in previous studies, including genetic studies.26, 27 All participants smoked at least 10 cigarettes/day and were otherwise medically healthy. Subjects were evaluated with the Structured Clinical Interview for DSM-IV28 and subjects that were dependent on alcohol or drugs (other than nicotine) or affected with any major psychiatric disorder were excluded from the study. A urine drug screen verified lack of drug use other than nicotine. Demographic information and smoking-related characteristics for the laboratory subjects are shown in Supplemental Information (Table S1).
