Marijuana Craving Questionnaire: development and initial validation of a self-report instrument.

AIMS: To develop and validate a multi-dimensional questionnaire on marijuana craving. DESIGN AND MEASUREMENTS: Current marijuana smokers (n = 217) not seeking treatment completed a 47-item Marijuana Craving Questionnaire (MCQ) and forms assessing demographics, drug use history, marijuana quit attempts and current mood. FINDINGS: Exploratory and confirmatory factor analyses indicated that a four-factor solution best described the item structure. Factor subscales derived from the 17 items with significant loadings had respectable internal consistencies and were stable across settings and subgroups. The subscales exhibited low to moderate, positive intercorrelations and were significantly correlated with marijuana use history and a wide range of single-item measures of craving. CONCLUSIONS: Findings suggested that four specific constructs characterize craving for marijuana: (1) compulsivity, an inability to control marijuana use; (2) emotionality, use of marijuana in anticipation of relief from withdrawal or negative mood; (3) expectancy, anticipation of positive outcomes from smoking marijuana; and (4) purposefulness, intention and planning to use marijuana for positive outcomes. These data indicate that the MCQ is a valid and reliable instrument for assessing marijuana craving in individuals not seeking drug abuse treatment and that marijuana craving can be measured in the absence of withdrawal.

Ibogaine: complex pharmacokinetics, concerns for safety, and preliminary efficacy measures.

Ibogaine is an indole alkaloid found in the roots of Tabernanthe Iboga (Apocynaceae family), a rain forest shrub that is native to western Africa. Ibogaine is used by indigenous peoples in low doses to combat fatigue, hunger and thirst, and in higher doses as a sacrament in religious rituals. Members of American and European addict self-help groups have claimed that ibogaine promotes long-term drug abstinence from addictive substances, including psychostimulants and opiates. Anecdotal reports attest that a single dose of ibogaine eliminates opiate withdrawal symptoms and reduces drug craving for extended periods of time. The purported efficacy of ibogaine for the treatment of drug dependence may be due in part to an active metabolite. The majority of ibogaine biotransformation proceeds via CYP2D6, including the O-demethylation of ibogaine to 12-hydroxyibogamine (noribogaine). Blood concentration-time effect profiles of ibogaine and noribogaine obtained for individual subjects after single oral dose administrations demonstrate complex pharmacokinetic profiles. Ibogaine has shown preliminary efficacy for opiate detoxification and for short-term stabilization of drug-dependent persons as they prepare to enter substance abuse treatment. We report here that ibogaine significantly decreased craving for cocaine and heroin during inpatient detoxification. Self-reports of depressive symptoms were also significantly lower after ibogaine treatment and at 30 days after program discharge. Because ibogaine is cleared rapidly from the blood, the beneficial aftereffects of the drug on craving and depressed mood may be related to the effects of noribogaine on the central nervous system.

Challenges in the manipulation, assessment and interpretation of craving relevant variables.

The nature of drug craving and its role in the addictive process is a contentious issue in the addiction sciences. There are numerous disputes regarding the definition, assessment, manipulation and interpretation of craving, and progress toward resolving the enigmas of craving confronts numerous conceptual and methodological challenges. Greater attention to certain fundamental principles of measurement and manipulation should generate immediate and substantial improvements in efforts to understand and control alcohol craving. This paper provides suggestions for enhancing the measurement of self-reported alcohol craving and improving the manipulation of alcohol craving under controlled laboratory conditions. With regard to measurement, single-item scales commonly employed in craving research tend to be handicapped by limited reliability and validity. Multi-item craving scales are more likely to provide the accuracy required to accurately discriminate between different levels of craving across individuals or across different settings. Conceptual and practical considerations for the selection of multi-item craving instruments are discussed. With regard to the manipulation of alcohol craving in the laboratory, recent meta-analyses suggest that alcohol craving effects in such research may be relatively weaker than craving effects found in similar research with other addicts. Therefore, laboratory-based investigations into the nature of alcohol craving should utilize procedures and assessments that are particularly sensitive to the detection of alcohol craving. This paper offers methodological recommendations for enhancing the magnitude of alcohol craving effects generated in laboratory research.

Tobacco craving: intensity-related effects of imagery scripts in drug abusers.

Two experiments were conducted to determine whether active imagery would elicit tobacco craving in smokers with histories of drug abuse who were not interested in quitting smoking. In Experiment 1, the authors used scripts that contained positive, negative, or neutral affective content with and without descriptions of smoking urge. Scripts with urge content and negative affect scripts increased subjective reports of tobacco craving. An interaction between affective manipulation and urge content was observed on self-reported mood. In Experiment 2, positive affect scripts that varied in amount of urge content produced an orderly increase in tobacco craving as a function of urge intensity, suggesting that changes were specific to the imagery manipulation. In both experiments, increases in tobacco craving were positively correlated with craving for drug of choice, suggesting that stimuli that engender smoking urges may occasion craving for other drugs of abuse.

Smoking after nicotine deprivation enhances cognitive performance and decreases tobacco craving in drug abusers.

This study investigated the effects of nicotine deprivation and smoking on cognitive abilities and tobacco craving. Twenty smokers with histories of drug abuse completed the Questionnaire on Smoking Urges (QSU) and two cognitive tests before and after smoking two cigarettes during two 90-min sessions. After two cigarettes were smoked at Session 1, subjects were tobacco abstinent for 18 h until Session 2 the next morning. Response time on a logical reasoning test was unchanged by tobacco deprivation and was faster after smoking on Session 2. Deprivation slowed responding on a letter search test, which was reversed by smoking to pre-deprivation baseline. Tobacco deprivation increased scores on the QSU; smoking after deprivation reduced craving scores to smoking baseline levels. These results confirmed the utility of the QSU to measure changes in craving induced by tobacco deprivation and smoking. Further, the data suggest that deprivation-induced deficits and smoking-induced enhancements in performance may be specific to certain cognitive domains.

Laboratory validation study of drug evaluation and classification program: alprazolam, d-amphetamine, codeine, and marijuana.

The Drug Evaluation and Classification (DEC) program is used by police agencies to identify drivers impaired because of drug use and to determine the class(es) of drug causing the impairment. The primary goal of this study was to determine the validity of the DEC evaluation in predicting whether research volunteers were administered alprazolam, d-amphetamine, codeine, or marijuana. A secondary goal was to determine the accuracy of Drug Recognition Examiners (DREs) in detecting if subjects were dosed with these drugs. Community volunteers (n = 48) were administered alprazolam (0, 1, 2 mg), d-amphetamine (0, 12.5, 25 mg), codeine (0, 60, 120 mg), or marijuana (0, 3.58% THC) in a double-blind, randomized, between-subject design. A single drug dose or placebo was administered at each experimental session, and blood samples were obtained before and after dosing. With the exception of marijuana, plasma drug concentration was at or near maximum during the DEC evaluation. The ability of the DEC evaluation to predict the intake of alprazolam, d-amphetamine, codeine, or marijuana was optimal when using 2-7 variables from the evaluation. DREs' decisions of impairment were consistent with the administration of any active drug in 76% of cases, and their drug class decisions were consistent with toxicology in 32% of cases, according to standards of the International Association of Chiefs of Police. These findings suggest that the DEC evaluation can be used to predict accurately acute administration of alprazolam, d-amphetamine, codeine, and marijuana and that predictions of drug use may be improved by focusing on a subset of variables.

Mechanisms of alcohol craving and their clinical implications.

Craving for alcohol is frequently given as a reason for drinking and is often used as a surrogate measure in studies of alcoholism and its treatment. Despite this wide use, there is little consensus on what craving for alcohol means, the best way to measure it, what mechanism accounts for the urge to drink, or what is its true relationship to alcohol use. This chapter reviews theoretical and measurement issues about the possible mechanisms involved in craving for alcohol and the clinical implications of evidence supporting them. Until recently, most instruments for assessing craving assumed it was a univariate construct and usually contained only one or a few items. Several multi-item and multidimensional rating instruments have now been developed that offer the promise of more useful assessment of clinically relevant behavior. Most models of craving have assumed that a consistent and positive relationship exists between craving and drinking. The incentive sensitization model and the cognitive theory of drug use and drug urges may account better than the older models for the frequent clinical observation of a dissociation between craving and drinking. However, no single model or theory of craving accounts for the wide variation in findings reviewed here, suggesting that multiple mechanisms may be involved. A comprehensive, multidisciplinary approach is necessary to elucidate the nature of craving for alcohol and its implications for pharmacological and psychosocial treatment of alcoholism.

Laboratory validation study of drug evaluation and classification program: ethanol, cocaine, and marijuana.

The Drug Evaluation and Classification (DEC) program is used by police agencies to determine if individuals are behaviorally impaired because of drug use, and, if impaired, to determine the class of drug(s) causing the impairment. Although widely used, the validity of the DEC evaluation has not been rigorously tested. The primary goal of this study was to determine the validity of the variables of the DEC evaluation in predicting whether research volunteers had been administered ethanol, cocaine, or marijuana; a secondary goal was to determine the accuracy of trained police officers (Drug Recognition Examiner, DRE) in detecting whether subjects had been dosed with ethanol, cocaine, or marijuana. Community volunteers (n = 18) with histories of drug use received ethanol (0, 0.28, 0.52 g/kg), cocaine (4, 48, 96 mg/70 kg), and marijuana (0, 1.75, 3.55% THC) in a double-blind, randomized, within-subjects design. A single drug dose or placebo was administered during each of nine experimental sessions, and blood samples were obtained before and periodically after dosing. With the exception of marijuana, plasma drug concentration was at or near the observed maximum during the DEC evaluation. The ability of the DEC evaluation to predict the intake of ethanol, cocaine, or marijuana was optimal when using 17-28 variables from the evaluation. When DREs concluded impairment was due to drugs other than ethanol, their opinions were consistent with toxicology in 44% of cases. These findings suggest that the DEC evaluation can be used to predict accurately acute administration of ethanol, cocaine, or marijuana, and that predictions of drug use may be improved if DREs focused on a subset of variables.

Smoking following myocardial infarction: a critical review of the literature.

This paper critically reviews the available research on the effects of smoking cessation following acute myocardial infarction (MI). Studies that have examined the rate of smoking cessation following an MI indicate that approximately 1/3 to 1/2 of the smokers who suffer from MI subsequently reduce or quit smoking. Furthermore, studies that have examined subsequent mortality and morbidity suggest that individuals who quit smoking following MI exhibit lower mortality and morbidity than those who continue to smoke. It is argued that past studies may have overestimated post-MI smoking cessation rates, and by failing to control for a priori differences between quitters and continuing smokers (e.g., MI severity) may have underestimated the negative effects of smoking following MI. Suggestions for future research are proposed.

The index of choice: indications of methadone patients' selection of naltrexone treatment.

Self-report inventories from 35 male methadone patients were examined for possible indicators of intent to choose naltrexone treatment. The index of choice, a composite score derived from the analysis, was developed for each patient and compared to naltrexone treatment status at 6-month follow-up. There was a highly significant relationship between scores on the index of choice and the actual process of naltrexone selection. Patients who elected to detoxify from methadone, who were less confident of their ability to remain opiate-free, and who also expressed greater fear of losing the security that maintenance had helped them attain, intended to choose, exhibited greater interest in, and actually selected naltrexone treatment more often. A significant number of maintenance patients who had been prescribed methadone at higher doses and for longer periods of time rejected naltrexone. Failure is the factor that seems to motivate methadone patients to respond to the selection process. Although perceptions of "failure to remain free of illicit opiates" may have enhanced interest in naltrexone, perceptions of "failure to detoxify from methadone" diminished naltrexone's appeal, and actual "failure to remain free of illicit opiates" following methadone detoxification precluded patient participation. Thus, dilemmas appeared to exist. The index of choice may prove to be effective in the evaluation of these dilemmas encountered by patients throughout the selection process, and recommendations for intervention are made. Cautious application of the index of choice is advised until the relationships with retention and success in naltrexone treatment are more clearly demonstrated in future research.