Nicotine Differences in Smokers

Twenty participants will have 2 Experimental Session on 2 separate days. Experimental Session 1 will determine if smokers can reliably discriminate 0.1mg nicotine/pulse nicotine from saline. Experimental Session 2 will determine if smokers can discriminate 0.05, 0.025, and 0.0125 mg nicotine/pulse of nicotine from saline.

Hypothesis: The threshold for discrimination will be 0.05 mg nicotine/pulse and the doses below that (0.025, and 0.0125 mg nicotine/pulse) will be subthreshold.

Exploratory Aim: To explore the relationship between the threshold for subjective drug effects and drug discrimination.

Inclusion criteria

• Female and male smokers, aged 18 to 65 years veterans and non-veterans who have been smoking tobacco cigarettes for at least a year
• smoke ≥ 5 cigs/day ;
• urine cotinine levels > 100 ng/mL consistent with nicotine intake of an active smoker (23)
• not seeking treatment at the time of the study for nicotine dependence
• Good health as verified by medical history, screening examination, and screening laboratory tests
• For women, not pregnant as determined by pregnancy screening, nor breast feeding, and using acceptable birth control methods.

Exclusion criteria

• History of major medical or psychiatric disorders that the physician investigator deems as contraindicated for the subject to be in the study
• regular use of psychotropic medication (antidepressants, antipsychotics, or anxiolytics)
• current alcohol or substance dependence for any other recreational or prescription drugs other than nicotine
• use of e-cigarettes more than 10 days in the past 30 days
• urine drug screening indicating recent illicit drugs use (with the exception of marijuana).