Relationships Between the Nicotine Metabolite Ratio and Laboratory Assessments of Smoking Reinforcement and Craving Among Adults in a Smoking Cessation Trial.

Introduction: People who metabolize nicotine more quickly are generally less successful at quitting smoking. However, the mechanisms that link individual differences in the nicotine metabolite ratio (NMR), a phenotypic biomarker of the rate of nicotine clearance, to smoking outcomes are unclear. We tested the hypotheses that higher NMR is associated with greater smoking reinforcement, general craving, and cue-induced cigarette craving in a treatment-seeking sample.

The impact of three weeks of pre-quit varenicline on reinforcing value and craving for cigarettes in a laboratory choice procedure.

Rationale: Varenicline, a partial nicotinic agonist, is theorized to attenuate pre-quit smoking reinforcement and post-quit withdrawal and craving. However, the mechanisms of action have not been fully characterized, as most studies employ only retrospective self-report measures, hypothetical indices of reinforcing value, and/or nontreatment-seeking samples.

Objectives: The current research examined the impact of pre-quit varenicline (vs.

Caffeine enhances sustained attention among adolescents.

Despite the growing interest in caffeine use and its effects among adolescents, and a large literature on caffeine and attention among adults, there is a lack of experimental work examining the impact of caffeine on sustained attention among adolescents. We evaluated the acute effects of caffeine (vs. placebo) during a long (33-min) classic vigilance task among 31 adolescents (aged 12-17; 15 female; median caffeine use = 28 mg/day).