Varenicline Pharmacological and Expectancy Effects on Medication Adherence (Balanced Placebo Design With Varenicline: Pharmacological and Expectancy Effects on Medication Adherence)

The current proposal will utilize the double-blind balanced placebo design to differentiate expectancies versus pharmacologic mechanisms of varenicline administered to varenicline naïve smokers seeking treatment (N = 80) for two-weeks. Race block randomization (controlling for baseline expectancies) will be used to randomize participants. The double-blind balanced placebo design includes a cross-balanced medication administration (active medication v. placebo) and instructional set (told truth v. deception) resulting in four groups of smokers seeking treatment (n = 20 for each): (1) told therapeutic dose (TD) medication + received TD medication; (2) told TD medication + received placebo; (3) told low dose (LD) medication+ received TD dose medication; (4) told LD medication + received placebo. Participants will be told they received low dose (rather than placebo) due to concerns that participants will not take a medication that they believe to be a placebo. Ecological momentary assessments (EMA) in the form of Daily Dairies delivered via smartphone will assess real-time side effects, withdrawal symptoms, cigarettes smoked, medication use, and reasons for medication non-adherence. The current proposal will test the following specific aims:

Specific Aim 1: Examine the main effects of instructional set and pharmacology. Hypothesis 1: Main effects for TD instructional set and active medication administration will result in reduced medication adherence compared with LD instructional set and placebo medication.

Specific Aim 2: Examine the interaction between instructional set and pharmacology. Hypothesis 2: There will be a synergistic (i.e., non-additive) effect between instructional set and pharmacology. Specifically, those assigned to the TD instructional set and active medication group will result in a 50% discontinuation compared to a 20% discontinuation in the TD instructional set and placebo medication group.

Exploratory Aim: Evaluate moderators of pharmacology and expectancy effects on medication adherence. First, we will conduct exploratory examination of baseline medication expectancies moderating the relationship between pharmacology and medication adherence. Second, we will conduct an exploratory evaluation of potential moderators (e.g., gender and race) of pharmacology and baseline medication expectancy.