Preliminary test of cigarette nicotine discrimination threshold in non-dependent versus dependent smokers

Abstract

Background Despite its potential for understanding tobacco dependence, behavioral discrimination of nicotine via smoking has not been formally examined as a function of nicotine dependence level. Methods Spectrum research cigarettes were used to compare non-dependent with dependent smokers on the lowest content of nicotine they could discriminate (i.e., “threshold”). Dependent (n=21; 16 M, 5 F) or non-dependent (n=7; 4 M, 3 F) smokers were tested on ability to discriminate between cigarettes with nicotine contents of 17, 11, 5, 2, and 1 mg/g, one per session, from an “ultra-low” cigarette with 0.4 mg/g (all had 9–10 mg “tar”). All abstained from smoking overnight prior to sessions, and number of sessions was determined by the lowest nicotine content they could reliably discriminate from the ultra-low on >80% of trials (i.e., ≥5 of 6). Subjective perceptions and cigarette choice behavior were also assessed and related to discrimination behavior. Results Discrimination thresholds (and most perceptions) did not differ between dependent and non-dependent smokers, with median thresholds of 11 mg/g for both subgroups. Yet, “liking” and puff choice for threshold cigarettes were greater in dependent but not non-dependent smokers, while cigarettes with nicotine contents below threshold did not support “liking” or choice in both groups. Conclusions In sum, this preliminary study suggests threshold for discriminating nicotine via smoking may not vary by dependence level, and further study is needed to confirm that cigarettes unable to be discriminated are also not reinforcing.

Evaluation of menthol per se on acute perceptions and behavioral choice of cigarettes differing in nicotine content

“…Finally, the association of perceptions with cigarette choice observed here may be specific to smokers who are nicotine dependent, as non-dependent smokers may have similar perceptions but less choice of the moderate nicotine cigarette. Such a finding would be consistent with their lack of dependence on nicotine reinforcement (virtually by definition) and comparable to our prior test of nicotine discrimination threshold and choice between groups due to their presence vs absence of dependence (Perkins et al, 2017).…”

“…Among the implications of our results, differences in perception ratings and choice behavior should be smaller in response to cigarettes differing less markedly in nicotine content, and the association between perception and choice of cigarettes may be comparably attenuated, relative to the moderate vs very low nicotine cigarettes here (Perkins et al, 2017). The current study intentionally compared those Spectrum cigarettes differing most widely in nicotine content while similar in "tar" and matched on menthol.…”

“…Yet, that was why exposure to each cigarette on each trial was limited to four controlled puffs, to avoid smoke toxicity or satiation across the half of all trials in which the moderate nicotine cigarette was administered. We have not observed carry-over effects of this pattern and timing of controlled smoking of different cigarettes following overnight abstinence (Perkins et al, 2017). We also chose four puffs per exposure based on prior research with Spectrum cigarettes (Hatsukami et al, 2013), and the fact that subjective ratings of cigarettes are often formed within the first few puffs (Hasenfratz et al, 1993).…”

“…Hatsukami et al, 1988). Note that half the exposures here involved very low nicotine intake, further minimizing chances of nicotine toxicity or satiation, as in similar research comparing responses between cigarettes within a session (Perkins et al, 2002(Perkins et al, , 2017. After the four puffs in each of these 10 trials, participants completed the brief ACP measure on their subjective perceptions of that cigarette (see Measures section of Methods, above).…”

Research on Behavioral Discrimination of Nicotine May Inform FDA Policy on Setting a Maximum Nicotine Content in Cigarettes

“…12 Also assessed for each cigarette smoked in each session were ratings on the Acute Cigarette Perception (ACP) scale, 17 a brief self-reported measure of subjective perceptions of the cigarette just smoked, similar to perceptions often related to drug discrimination behavior. 16,25 The ACP consists of five items asking how much “nicotine,” “liking,” and “flavor” were experienced, and how “satisfying” and “strong” the cigarette was, with each item rated on a 0–100 visual analog scale, anchored by “not at all” to “very much.” Aside from the ACP, a separate rating obtained here assessed how “similar to own brand” the cigarette was. Finally, after completing all discrimination trials, a “choice” test as to which cigarette they preferred to smoke (ie, self-administer) ended the session.…”