Mood, nicotine, and dose expectancy effects on acute responses to nicotine spray.

INTRODUCTION: We recently showed effects of nicotine dose and nicotine expectancy on some responses to cigarette smoking, with generally no influence of induced mood on these effects. The present study extended this line of research to Nicotrol nasal spray, to determine whether formulation (spray vs. smoking) alters responses. METHODS: Smokers abstained overnight before each of two virtually identical sessions, involving negative or positive mood induction. They were randomized to one of five groups, four comprising the 2 x 2 balanced placebo design, varying actual and expected dose of nicotine in the nasal spray, and the fifth group a no-spray control. Dependent measures included self-reported affect, craving, withdrawal, and spray ratings of "liking" and "how much nicotine." Analyses were limited to those whose nicotine expectancies were manipulated successfully (N = 48). RESULTS: The following results matched those from our smoking study: expecting nicotine increased liking; expected, but not actual, nicotine dose increased dose perception; neither actual nor expected nicotine dose had much influence on affect or withdrawal; and mood had no influence on these effects. However, both actual and expected nicotine dose decreased craving in response to spray, contrary to our prior study with smoking. DISCUSSION: Formulation made little difference in some effects of nicotine and expectancies, but other effects differed by formulation. Some of these findings, particularly for craving reduction, may have implications for enhancing the acute therapeutic effects of nasal spray and, perhaps, other medications in smokers trying to maintain abstinence after quitting.

Dopamine and opioid gene variants are associated with increased smoking reward and reinforcement owing to negative mood.

Negative mood increases smoking reinforcement and risk of relapse. We explored associations of gene variants in the dopamine, opioid, and serotonin pathways with smoking reward ('liking') and reinforcement (latency to first puff and total puffs) as a function of negative mood and expected versus actual nicotine content of the cigarette. Smokers of European ancestry (n=72) were randomized to one of four groups in a 2x2 balanced placebo design, corresponding with manipulation of actual (0.6 vs. 0.05 mg) and expected (told nicotine and told denicotinized) nicotine 'dose' in cigarettes during each of two sessions (negative vs. positive mood induction). Following mood induction and expectancy instructions, they sampled and rated the assigned cigarette, and then smoked additional cigarettes ad lib during continued mood induction. The increase in smoking amount owing to negative mood was associated with: dopamine D2 receptor (DRD2) C957T (CC>TT or CT), SLC6A3 (presence of 9 repeat>absence of 9), and among those given a nicotine cigarette, DRD4 (presence of 7 repeat>absence of 7) and DRD2/ANKK1 TaqIA (TT or CT>CC). SLC6A3, and DRD2/ANKK1 TaqIA were also associated with smoking reward and smoking latency. OPRM1 (AA>AG or GG) was associated with smoking reward, but SLC6A4 variable number tandem repeat was unrelated to any of these measures. These results warrant replication but provide the first evidence for genetic associations with the acute increase in smoking reward and reinforcement owing to negative mood.