Belief about drug assignment and abstinence in treatment of cigarette smoking using nortriptyline

Abstract

This study assessed the relationship between beliefs about drug assignment and abstinence status in two treatment studies using nortriptyline hydrochloride as an adjunct to smoking cessation. Smokers (N = 345) drawn from two clinical trials were asked at the final follow-up (FFU) at 52 or 64 weeks whether they believed they had received active or placebo drug. Responses were obtained from 262 participants, or 76% of the sample. Biochemically verified abstinence was collected at end of treatment (EOT) and FFU. In both studies, participants were correct in guessing drug assignment. At FFU, belief about drug assignment was not related to abstinence for either active or placebo participants. Participants who received active drug and who were smoking at EOT were more likely to believe they had received placebo than active drug participants who were abstinent at EOT. We found no significant relationship between belief about drug and abstinence status for placebo participants at EOT. Baseline variables did not significantly predict correctness of drug identification. Participants who experienced drug side-effects not easily attributable to nicotine withdrawal were more likely to identify their drug assignment as nortriptyline. We conclude that experience during the active treatment period, including side-effects and treatment success, may be related to belief about drug assignment, that the field would be well served by at least two assessments of blindness in clinical trials, and that discrepancy between these findings and those regarding nicotine replacement therapy may be related to differences in dependent variables.