Measurement of smoking behavior: Comparison of self-reports, returned cigarette butts, and toxicant levels.

A basic tenet of empirical research on cigarette smoking behavior is the systematic assessment of patterns of use. However, the large majority of extant research relies on smokers' retrospective reports of their average number of cigarettes per day (CPD), a measure that may be variable in terms of reliability and validity. Using data from 3 previously published studies of non-treatment-seeking daily smokers (combined N = 89), this analysis examined the reliability of self-reported CPD, the consistency of returned cigarette butts each day over 4 consecutive 24-hr periods, the validity of self-reported CPD compared with returned cigarette butts, and the relationship of CPD and returned cigarette butts to toxicant exposure. Results showed that self-reported CPD was reliable across telephone and in-person screening interviews (r = .87, p < .01). Although average self-reported CPD and returned cigarette butt counts did not differ significantly, t(87) = -1.5 to 0.3, all ns, butt counts revealed a wider range of variability in daily smoking behavior. In addition, self-reported cigarette use exhibited substantial digit bias (Whipple's index = 413.8), meaning that participants tended to round their estimates to values ending in 0 or 5. Cigarette butt counts, but not self-reported CPD, were significantly associated with exposure to smoke toxicants. However, this former relationship was revealed to be linear, but not curvilinear, in nature. These findings have implications for both research and treatment efforts, as researchers often rely on accurate assessment of CPD to predict a variety of smoking-related outcomes. (PsycINFO Database Record

Effects of gender on ketamine-induced conditioned placed preference and urine metabonomics.

OBJECTIVE: The aim of this study was to examine whether or not there was a gender difference in CPP (conditioned placed preference) induced by ketamine and to further explore the effect of sex on metabolic responses to ketamine inducing in SD rats. METHODS: We measured ketamine-induced conditioned place preference and ketamine-induced metabolic changes in urine by using (1)H nuclear magnetic resonance (NMR) coupled with principal component analysis (PCA), partial least squares (PLS) and orthogonal signal correction (OSC) analysis. RESULTS: In the CPP experiment, ketamine served as a positive reinforcing agent in both male and female rats, but, in particularly, the preference score of female rats was significantly higher than that of male rats. Compared with male rats, the metabolic trajectory fluctuation of the female rats was relatively larger. At the same time, different metabolites (1, 3-dimethyluric acid, cysteine-S-sulfate, glyceraldehydes, glycine, ribitol, acetoacetic acid, creatine, 3-methyladenine, hypotaurine, taurine, dimethylglycine and theobromine) between male and female rats were found. CONCLUSIONS: Female Sprague-Dawley rats were more sensitive to the ketamine-induced CPP than male rats. The fluctuation ranges of metabolic trajectory and metabolite contents in urine were both different between female and male rats. This would provide targeted suggestions for ketamine abuser, for example, men and women should take different drug withdrawal therapeutic methods.

Contingency management for the treatment of methamphetamine use disorders.

OBJECTIVE: Theory and some preliminary evidence suggest that contingency management may be an effective treatment strategy or adjunct to psychosocial treatment for methamphetamine use disorders. An experimentally rigorous investigation on the topic was provided by a large multisite trial conducted under the auspices of the Clinical Trials Network of the National Institute on Drug Abuse. METHOD: The authors report data on 113 participants who were diagnosed with methamphetamine abuse or dependence. They were randomly assigned to receive 12 weeks of either treatment as usual or treatment as usual plus contingency management. Urine samples were tested for illicit drugs, and breath samples were tested for alcohol. The reinforcers for drug-negative samples were plastic chips, some of which could be exchanged for prizes. The number of plastic chips drawn increased with each week of negative samples but was reset to one after a missed or positive sample. RESULTS: The participants in both groups remained in treatment for equivalent times, but those receiving contingency management in addition to usual treatment submitted significantly more negative samples, and they were abstinent for a longer period of time (5 versus 3 weeks). CONCLUSIONS: These results suggest that contingency management has promise as a component in treatment strategies for methamphetamine use disorder.

A controlled trial of daily versus thrice-weekly buprenorphine administration for the treatment of opioid dependence.

This study was aimed at determining whether thrice-weekly administration of buprenorphine is as effective as daily administration for treating opioid dependence. A total of 60 treatment-seeking opioid addicts were randomly assigned to take buprenorphine tablets sublingually either every day (8 mg) or thrice-weekly (16 mg on Mondays and Wednesdays and 24 mg on Fridays) over the course of a 12-week, double-blind, parallel trial. The buprenorphine dosing schedule had no significant effect on treatment retention. The rates of opioid-positive urine tests were significantly higher among those subjects who were given buprenorphine thrice weekly (58.5%) than among those who took it daily (46.6%). An analysis of the completers did not detect a significant effect of buprenorphine dosing schedule. The results obtained in our clinical trials indicate the advisability of daily doses of buprenorphine, at least at the beginning of a maintenance programme.

Smoking behaviour and compensation: a review of the literature.

RATIONALE: Compensation or compensatory smoking, accurately defined, deals with the question of whether switching to cigarette brands with different smoke yields is associated with a change in smoke uptake proportional to the change in machine-derived yields. The issue of compensation is important because it bears on whether switching to "lighter" brands means lower overall smoke intake or not. OBJECTIVES: The present review investigated whether and to what extend low yield cigarettes are smoked more intensively. In addition, published data on whether nicotine, "tar", or any other smoke constituent or property influence compensational smoking are summarized. METHODS: The studies on compensation were classified as follows: (1) studies on smoking behaviour in relation to cigarette yields (with and without brand switching); (2) studies on compensation for nicotine (switching between cigarettes which differ "only" in their nicotine yield, nicotine supplementation, manipulation of renal nicotine excretion, administration of nicotine agonists or antagonists); (3) studies on compensation for other factors (influence of tar, taste, irritation, draw resistance). In order to quantify the degree of compensation, an index is defined and applied to selected brand switching studies. This compensation index determines, in relative units, the degree to which a smoker responds to a change in smoke yields with a change in smoke uptake measured by suitable biomarkers. The role of vent blocking is also briefly discussed. RESULTS: Most of the studies which compare the smoking behaviour when smoking cigarettes with different smoke yields supply evidence for "partial" compensation, suggesting that cigarettes with lower yields are smoked more intensively than those with higher yields. These studies also show that a change in the daily number of cigarettes is not a common mechanism of compensation. Effective vent blocking during smoking is a rare event and can therefore also be regarded as an uncommon mechanism of compensation. Evaluation of a suitable subset of brand-switching studies revealed an average compensation of 50-60% of the nicotine yield. Compensation tended to be more complete when changing to cigarettes with higher yields than when changing to cigarettes with lower yields. In general, brand-switching studies do not supply information on the underlying causal factors responsible for compensatory smoking. Results of the nicotine supplementation studies are not conclusive: some report evidence of nicotine titration, others do not. A general problem with this type of investigation is that continuous nicotine application does not mimic the spike-wise application with cigarette smoking, and may lead to nicotine tolerance. There is limited evidence that cigarettes were smoked more intensively when the urinary clearance of nicotine was increased. A small number of studies provide some evidence that smoking intensity increased after smokers were administered a nicotine antagonist. Several reports indicate that tar, taste and sensory properties of the smoke as well as the draw resistance of the cigarette may play a role in compensatory smoking. Low-yield cigarettes usually have reduced pressure drops which smoke researchers have suggested leads to increased puff volume. This effect seems to be independent of the smoke yield of the cigarette. There is also some evidence that some smokers maintain a consistent pattern of smoking which works independent of any changes in nicotine or tar yields, taste or design features of the cigarette ("functional autonomy"). CONCLUSIONS: The available data suggest that smokers partially compensate for a different smoke yield. While the factors and their interaction responsible for compensational smoking are not fully understood, there are data suggesting that a subgroup of smokers may partially compensate for nicotine. Even in this subgroup of smokers, however, the relative importance of the pharmacological versus