However, because that study used an untreated control group rather than a placebo control group, the extent to which its results were due to a pharmacological effect versus an expectancy effect are unclear. The present study was designed initially to examine the effects of bupropion compared with placebo http://www.selleckchem.com/products/jq1.html on baseline and cue-elicited smoking urges in adult smokers. In view of the suggestion that treatment-seeking status may moderate the effects of medications for smoking cessation (Perkins et al., 2008), we also examined whether intention to quit moderated the effects of bupropion. Given the clinical efficacy of bupropion in treatment-seeking smokers and its ability to reduce craving and withdrawal symptoms in some human laboratory studies (Mooney & Sofuoglu, 2006), we hypothesized that bupropion would reduce the effects of abstinence on these measures, particularly in participants who intended to quit smoking.
Methods Participants Participants were required to be 18 years or older, to have smoked at least 20 cigarettes/day for at least the past year, and to have Fagerstr?m Test for Nicotine Dependence (Heatherton, Kozlowski, Frecker & Fagerstr?m, 1991) scores of 6 or higher. The Structured Clinical Interview for Diagnostic and statistical manual of mental disorders, fourth edition (First, Spitzer, Gibbon, & Williams, 1994) was used to rule out those with current Axis I disorders. Other exclusionary criteria included positive urine drug or pregnancy tests, positive breath alcohol levels at any visit, use of any psychoactive medication, and the presence of any medical condition that might interact with bupropion.
Procedures were approved by the institutional review board involved. Of the 27 participants enrolled, 25 completed the study. Study design and medication Participants first completed questionnaires on demographics and other individual difference measures. Intention to quit smoking was measured using the stages-of-change algorithm (DiClemente et al., 1991). Participants then underwent three laboratory sessions, spaced 7 days apart. In Session 1, participants were not abstinent and not taking any medication. In Sessions 2�C3, participants were tested under 5-hr abstinent conditions after 1 week of either 300 mg/day sustained-release bupropion (GlaxoSmithKline, Research Triangle Park, NC) or matching placebo (ProClinical Inc., Phoenixville, PA).
The bupropion dose was 150 mg/day for the first 3 days and was increased on day 4 to 300 mg/day (150 mg twice daily), according to the manufacturer’s instructions. Medications were administered under double-blind Entinostat conditions, in divided organizers, with dose order counterbalanced across participants. Medication compliance was checked weekly by pill count. Laboratory procedures Upon arrival, participants provided breath samples for the assessment of carbon monoxide (CO) levels (Smokerlyzer; Bedfont Scientific Ltd., Kent, United Kingdom).