Relating individual differences in the reinforcing value of smoking and dependence severity to nicotine exposure levels in vulnerable populations

Cigarette smoking is overrepresented in populations with psychiatric conditions and socioeconomic disadvantage. Greater understanding of the role of reinforcement and nicotine dependence in smoking among vulnerable populations may facilitate development of better targeted interventions to reduce smoking. Prior research demonstrated that individual differences in the reinforcing value of smoking and nicotine-dependence severity predicted total nicotine-exposure in vulnerable populations. The present study uses multivariate regression to address two aims: (1) Quantify the degree to which the reinforcing value of smoking, assessed using the Cigarette Purchase Task (CPT), and dependence severity assessed using the Fagerström Test of Nicotine Dependence and Brief Wisconsin Inventory of Smoking Dependence Motives (B-WISDM) each account for individual differences in cotinine-plus-3'-hydroxycotinine (COT+3HC) levels. (2) Explore whether there is overlap in the variance accounted for by the CTP, FTND, and B-WISDM. Participants were 628 adults with co-morbid psychiatric conditions or socioeconomic disadvantage who smoked daily. The CPT, FTND, and B-WISDM models accounted for 23.76%, 32.45%, and 29.61% of the variance in COT+3HC levels, respectively. Adding CPT to the FTND model failed to increase the variance accounted for and adding it to the B-WISDM model did so by only 1.2% demonstrating considerable overlap in the variance in nicotine exposure levels accounted for by these three instruments. These results provide new knowledge on the relationship between individual differences in the reinforcing value of smoking and nicotine-exposure levels and suggest differences in reinforcing value may underpin a considerable portion of the variance in nicotine exposure accounted for by dependence severity.

Relating individual differences in nicotine dependence severity to underpinning motivational and pharmacological processes among smokers from vulnerable populations

We examined whether elucidating underpinning smoking motivation and related pharmacological processes enhances understanding of nicotine dependence among smokers from vulnerable populations. Data were obtained between Oct, 2016 and Sept, 2019 from 745 adult smokers with co-morbid psychiatric conditions or socioeconomic disadvantage at University of Vermont, Brown University, Johns Hopkins University. Smoking motivation was assessed using the Cigarette Purchase Task (CPT), a behavioral-economic task that models the relative reinforcing value of smoking under varying monetary constraint. Dependence severity was measured using the Heaviness of Smoking Index (HSI), Fagerström Test for Nicotine Dependence total scores (FTND), and FTND total scores minus items 1 and 4 (FTND_2,3,5,6). We also assessed associations between dependence severity and smoking motivation with nicotine levels and metabolism rate. Principal Component Analysis was used to examine the latent structure of the conventional five CPT indices; bivariate and multivariable modeling was used to test associations. Factor analysis resulted in a two-factor solution, Amplitude (demand unconstrained by price) and Persistence (price sensitivity). CPT latent factors were associated with each dependence-severity measure (ps ≤ 0.0001), with associations stronger for Amplitude than Persistence across each, especially HSI which was exclusively associated with Amplitude_. Amplitude and each dependence measure were associated with nicotine intake (ps ≤ 0.0002); Persistence was not (p = .19). Demand Amplitude more than Persistence appears key to understanding individual differences in dependence severity. Regarding potential application, the results suggest a need for interventions that more effectively target demand Amplitude to make greater headway in reducing smoking in vulnerable populations. Trial Registration:clinicaltrials.gov identifiers: NCT02232737, NCT02250664, NCT02250534.

[Comparative study of acupoint catgut embedding and bupropion hydrochloride sustained-release tablets for tobacco dependence]

OBJECTIVE

To compare the clinical efficacy of acupoint catgut embedding and bupropion hydrochloride sustained-release tablets in the treatment of tobacco dependence.

METHODS

A total of 100 patients with tobacco dependence who met the inclusion criteria were randomly divided into an acupoint catgut embedding group and a drug group, 50 cases in each group. In the acupoint catgut embedding group, acupoint catgut embedding was applied at Xinshu (BL 15), Shenmen (HT 7), Tianmei (Extra), Taichong (LR 3), the treatment was given once every 2 weeks for 4 times; The bupropion hydrochloride sustained-release tablets was orally administered in the drug group for 7 weeks, 150 mg each time, once a day for the first 3 days, twice daily from day 4 to day 7, and once a day after day 8. The Fagerström test for nicotine dependence (FTND) score before and after treatment, the 4th and 8th week smoking cessation rate, the continuous smoking cessation rate and efficacy, compliance rate and adverse reaction rate were compared in the two groups.

RESULTS

A total of 100 patients were enrolled, and 97 patients completed the study (loss rate was 3%), including 49 cases in the acupoint catgut embedding group and 48 cases in the drug group. The FTND scores in the two groups were lower than those before treatment (both P<0.05). There was no significant difference between the two groups after treatment (P>0.05). At the 4th and the 8th week, the smoking cessation rate in the acupoint catgut embedding group was 40.8% (20/49) and 79.6% (39/49) respectively, the smoking cessation rate in the drug group was 41.7% (20/48) and 83.3% (40/48) respectively, the two groups were equally effective (both P>0.05). The continuous smoking cessation rate in the acupoint embedding group was 40.8% (20/49), which was equivalent to 41.7% (20/48) in the drug group (P>0.05). The rate of complete compliance in the acupoint embedding group was 61.2% (30/49), which was significantly better than 37.5% (18/48) in the drug group (P<0.05). The adverse reaction rate in the acupoint catgut embedding group was 12.2% (6/49), which was significantly lower than 29.2% (16/48) in the drug group (P<0.05).

CONCLUSION

Acupoint catgut embedding can effectively improve the symptoms of tobacco dependence after smoking cessation. Its curative effect is close to that of bupropion hydrochloride sustained-release tablets, and it has good clinical compliance and less adverse reactions.

Is the Fagerström test for nicotine dependence invariant across secular trends in smoking? A question for cross-birth cohort analysis of nicotine dependence

BACKGROUND

The Fagerström Test for Nicotine Dependence (FTND), a derivation of the Fagerström Tolerance Questionnaire, was first published in 1991. The FTND remains one of the most widely used measures of nicotine dependence for studying genetic and epidemiological risk factors and the likelihood of smoking cessation. However, it is unclear whether secular trends in patterns of smoking alter the psychometric properties of the FTND and its interpretation.

METHODS

We examined measurement invariance in the lifetime and current FTND scores across birth cohorts using participants drawn from six study samples (N = 13,775).

RESULTS

We found significant (p < 0.05) measurement non-invariance in means and factor loadings of most FTND items by birth cohort, but effect sizes, ranging from r2 = 0.0001 to r2 = 0.0035, indicated that less than 0.5% of the model variance was explained by the measurement non-invariance for each factor loading. To assess its impact, we regressed the lifetime FTND latent variable on well-established factors associated with nicotine dependence (quitting smoking and the nicotinic acetylcholine receptor gene [CHRNA5] variant rs16969968, separately), and we observed that the regression coefficients were unchanged between models with and without adjustment for measurement non-invariance.

CONCLUSIONS

These findings suggest that possible FTND non-invariance that occurs across study samples of various birth years has a negligible impact on study results.