Perkins Kenneth A, Kunkle Nicole, Karelitz Joshua L, Perkins K A, Kunkle N, Karelitz J L
Western Psychiatric Institute and Clinic, University of Pittsburgh School of Medicine, 3811 O'Hara Street, Pittsburgh, PA 15213, USA.
Western Psychiatric Institute and Clinic, University of Pittsburgh School of Medicine, 3811 O'Hara Street, Pittsburgh, PA 15213, USA.
Drug Alcohol Depend. 2017 Jun 1;175:36-41. doi: 10.1016/j.drugalcdep.2017.01.033. Epub 2017 Mar 23.
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.
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; 16M, 5F) or non-dependent (n=7; 4M, 3F) smokers were tested on ability to discriminate between cigarettes with nicotine contents of 17, 11, 5, 2, and 1mg/g, one per session, from an "ultra-low" cigarette with 0.4mg/g (all had 9-10mg "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.
Discrimination thresholds (and most perceptions) did not differ between dependent and non-dependent smokers, with median thresholds of 11mg/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.
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.
尽管了解烟草依赖具有潜在意义，但通过吸烟对尼古丁进行行为辨别尚未作为尼古丁依赖水平的函数进行正式研究。
使用光谱研究香烟，比较非依赖吸烟者和依赖吸烟者对他们能够辨别的最低尼古丁含量（即“阈值”）。对依赖吸烟者（n = 21；16名男性，5名女性）或非依赖吸烟者（n = 7；4名男性，3名女性）进行测试，以确定他们区分尼古丁含量为17、11、5、2和1mg/g的香烟（每次测试一种）与尼古丁含量为0.4mg/g的“超低”香烟（所有香烟的“焦油”含量均为9 - 10mg）的能力。所有参与者在测试前一晚戒烟，测试次数由他们在超过80%的试验中能够可靠区分的最低尼古丁含量决定（即6次中有≥5次）。还评估了主观感受和香烟选择行为，并将其与辨别行为相关联。
依赖吸烟者和非依赖吸烟者的辨别阈值（以及大多数感受）没有差异，两个亚组的中位数阈值均为11mg/g。然而，依赖吸烟者对阈值香烟的“喜好”和抽吸选择更大，而非依赖吸烟者则不然，而尼古丁含量低于阈值的香烟在两组中均不支持“喜好”或选择。
总之，这项初步研究表明，通过吸烟辨别尼古丁的阈值可能不会因依赖水平而有所不同，需要进一步研究以确认无法辨别的香烟也不会起到强化作用。
