Effects of marijuana smoking on subjective ratings and tobacco smoking

Effects of Cannabis-Delivered THC on mood and negative attentional bias in the context of positive vs. neutral Alternatives-a pilot study

OBJECTIVE

To assess: (1) the acute effects of smoked marijuana (MJ) on negative attentional bias (NAB), (2) moderation of these effects by positive versus neutral alternatives, and (3) the associations of tetrahydrocannabinol (THC)-induced changes in NAB with changes in affect.

METHODS

Fourteen MJ users (1-4 uses/wk) smoked a THC cigarette on 1 day and a placebo cigarette on the other counterbalanced day. After smoking, participants freely gazed back and forth at a series of two side-by-side pictures pairs presented for 3000 ms (one negative, while the other was either positive or neutral) while eye gaze was tracked.

RESULTS

The effects of THC relative to placebo varied across time such that THC increased NAB during the early temporal component of threatening picture viewing, 333-858 ms after dual-picture onset, regardless of alternative picture valance. However, contrary to the attentional bias-causes affect hypothesis, during the early viewing phase THC-enhanced positive affect (PA) correlated positively with THC-induced NAB. In contrast, during the late phase (891-3000 ms) THC-enhanced PA did not correlate significantly with NAB, though THC-induced negative affect (NA) change did correlate positively with THC-induced change in NAB in the positive alternative condition.

CONCLUSIONS

We replicated findings of others showing that THC can enhance NAB during the early stages of threatening picture viewing. We extended previous results by demonstrating the THC-induced NAB is associated with increased PA during initial threat viewing, but with increased NA during later processing if positive alternatives are present.

Simulation of nanoparticle transport and adsorption in a microfluidic lung-on-a-chip device

The effect of air-borne nanoparticles (NPs) on human health is an active area of research, with clinical relevance evidenced by the current COVID-19 pandemic. As in vitro models for such studies, lung-on-a-chip (LOAC) devices can represent key physical and physiological aspects of alveolar tissues. However, widespread adoption of the LOAC device for NP testing has been hampered by low intra-laboratory and inter-laboratory reproducibility. To complement ongoing experimental work, we carried out finite-element simulations of the deposition of NPs on the epithelial layer of a well-established LOAC design. We solved the Navier-Stokes equations for the fluid flow in a three-dimensional domain and studied the particle transport using Eulerian advection-diffusion for fine NPs and Lagrangian particle tracking for coarse NPs. Using Langmuir and Frumkin kinetics for surface adsorption and desorption, we investigated NP adsorption under different exercise and breath-holding patterns. Conditions mimicking physical exercise, through changes in air-flow volume and breathing frequency, enhance particle deposition. Puff profiles typical of smoking, with breath-holding between inhalation and exhalation, also increase particle deposition per breathing cycle. Lagrangian particle tracking shows Brownian motion and gravitational settling to be two key factors, which may cooperate or compete with each other for different particle sizes. Comparisons are made with experimental data where possible and they show qualitative and semi-quantitative agreement. These results suggest that computer simulations can potentially inform and accelerate the design and application of LOAC devices for analyzing particulate- and microbe-alveolar interactions.

Cocaine + nicotine mixture enhances induction and expression of behavioral sensitization in rats

BACKGROUND

Psychoactive substance abuse is a health problem worldwide. Has been reported a high prevalence of use of tobacco and cocaine, either separately or in combination. Clinical and animal studies have suggested that the concurrent use of cocaine and nicotine reinforces the potency of one or both drugs and that nicotine may enhance the reinforcing effects of cocaine. Our study evaluated the combined effects of cocaine and nicotine on locomotor activity during the induction and expression phases of locomotor sensitization-a physiological mechanism that plays an important role in establishing some of the defining characteristics of drug abuse.

METHODS

We used Wistar rats which were dosed with cocaine, nicotine or cocaine and nicotine combination and recorded their locomotor activity in different phases of the experiment.

RESULTS

We found that a daily dose of cocaine combined with nicotine enhanced cocaine- and nicotine-induced locomotor activity, as well as induction and expression of locomotor sensitization. Moreover, we found that pretreatment with nicotine enhanced the locomotor sensitization expression.

CONCLUSION

These results suggest that concurrent use of cocaine and nicotine may result in co-abuse of these drugs.

Pregnenolone blocks cannabinoid-induced acute psychotic-like states in mice

Cannabis-induced acute psychotic-like states (CIAPS) represent a growing health issue, but their underlying neurobiological mechanisms are poorly understood. The use of antipsychotics and benzodiazepines against CIAPS is limited by side effects and/or by their ability to tackle only certain aspects of psychosis. Thus, safer wide-spectrum treatments are currently needed. Although the blockade of cannabinoid type-1 receptor (CB1) had been suggested as a therapeutical means against CIAPS, the use of orthosteric CB1 receptor full antagonists is strongly limited by undesired side effects and low efficacy. The neurosteroid pregnenolone has been recently shown to act as a potent endogenous allosteric signal-specific inhibitor of CB1 receptors. Thus, we tested in mice the potential therapeutic use of pregnenolone against acute psychotic-like effects of Δ⁹-tetrahydrocannabinol (THC), the main psychoactive component of cannabis. We found that pregnenolone blocks a wide spectrum of THC-induced endophenotypes typically associated with psychotic-like states, including impairments in cognitive functions, somatosensory gating and social interaction. In order to capture THC-induced positive psychotic-like symptoms (e.g. perceptual delusions), we adapted a behavioral paradigm based on associations between different sensory modalities and selective devaluation, allowing the measurement of mental sensory representations in mice. Acting at hippocampal CB1 receptors, THC impaired the correct processing of mental sensory representations (reality testing) in an antipsychotic- and pregnenolone-sensitive manner. Overall, this work reveals that signal-specific inhibitors mimicking pregnenolone effects can be considered as promising new therapeutic tools to treat CIAPS.

A review of the additive health risk of cannabis and tobacco co-use

INTRODUCTION

Cannabis and tobacco are the most widely used substances, and are often used together. The present review examines the toxicant exposure associated with co-use (e.g., carbon monoxide, carcinogens), co-use via electronic nicotine delivery systems (ENDS), and problematic methodological issues present across co-use studies.

METHOD

An extensive literature search through PubMed was conducted and studies utilizing human subjects and in vitro methods were included. Keywords included tobacco, cigarette, e-cigarette, ENDS, smoking, or nicotine AND marijuana OR cannabis OR THC.

RESULTS

Co-use may pose additive risk for toxicant exposure as certain co-users (e.g., blunt users) tend to have higher breath carbon monoxide levels and cannabis smoke can have higher levels of some carcinogens than tobacco smoke. Cannabis use via ENDS is low and occurs primarily among established tobacco or cannabis users, but its incidence may be increasing and expanding to tobacco/cannabis naïve individuals. There are several methodological issues across co-use research including varying definitions of co-use, sample sizes, lack of control for important covariates (e.g., time since last cigarette), and inconsistent measurement of outcome variables.

CONCLUSIONS

There are some known additive risks for toxicant exposure as a result of co-use. Research utilizing consistent methodologies is needed to further establish the additive risk of co-use. Future research should also be aware of novel technologies (e.g., ENDS) as they likely alter some toxicant exposure when used alone and with cannabis.

Acute subjective effects after smoking joints containing up to 69 mg Δ9-tetrahydrocannabinol in recreational users: a randomized, crossover clinical trial

RATIONALE

An increase in the potency of the cannabis cigarettes has been observed over the past three decades.

OBJECTIVES

In this study, we aimed to establish the impact of Δ9-tetrahydrocannabinol (THC) on the rating of subjective effects (intensity and duration of the effects), up to 23 % THC potency (69 mg THC) among recreational users.

METHODS

Recreational users (N = 24) smoked cannabis cigarettes with four doses of THC (placebo 29, 49 and 69 mg of THC) on four separate test days in a randomized, double-blind, placebo-controlled, crossover study. The participants filled in three different questionnaires measuring subjective effects during the exposure up to 8 h post-smoking. The 'high' feeling, heart rate, blood pressure and THC serum concentrations were also regularly recorded during these 8 h.

RESULTS

THC significantly increased the high feeling, dizziness, dry-mouthed feeling, palpitations, impaired memory and concentration, and 'down', 'sedated' and 'anxious' feelings. In addition, THC significantly decreased alertness, contentment and calmness. A cubic relationship was observed between 'feeling the drug' and 'wanting more'. The THC-induced decrease in 'feeling stimulated' and increase in anxiety lasted up to 8 h post-smoking. Sedation at 8 h post-smoking was increased by a factor of 5.7 with the highest THC dose, compared to the placebo.

CONCLUSIONS

This study shows a strong effect of cannabis containing high percentages of THC on the rating of subjective effects. Regular users and forensic toxicologists should be aware that the THC-induced increase in 'feeling sedated' continues longer with a 69 mg THC dose than with a 29 mg THC dose.

Achieving smoking abstinence is associated with decreased cocaine use in cocaine-dependent patients receiving smoking-cessation treatment

BACKGROUND

Past research suggests that a significant relationship exists between cigarette smoking and illicit-stimulant abuse. The present study evaluated the association between achieving smoking abstinence in response to smoking-cessation treatment (SCT) and illicit-stimulant abstinence in cocaine- and/or methamphetamine-dependent participants.

METHODS

Secondary analysis of a randomized, 10-week trial conducted at 12 substance use disorder (SUD) treatment programs. Two hundred and sixty seven adults, meeting DSM-IV-TR criteria for cocaine and/or methamphetamine-dependence and interested in quitting smoking were randomized to SUD treatment as usual plus SCT consisting of weekly individual smoking cessation counseling, extended-release (XL) bupropion (300 mg/day), nicotine inhaler, and contingency management for smoking abstinence. Illicit-stimulant-abstinence was measured by self-report and urine drug screens. Smoking abstinence was assessed via self-report and carbon monoxide levels.

RESULTS

A significant effect was found for the cocaine-dependent subsample (N=147) in which participants who stopped smoking were abstinent for illicit stimulants an average of 78.2% of the post-smoking-quit weeks (weeks 4-10) relative to 63.6% in participants who continued smoking (X(2)(1)=8.55, p<.01, d=0.36). No significant effects were found for the sample as a whole (N=249) or for the methamphetamine-dependent subsample (N=102).

CONCLUSIONS

The present results suggest that cocaine-dependent patients achieving smoking abstinence in response to SCT might evidence not only improved smoking outcomes but improved cocaine-use outcomes as well. Future research to replicate this finding appears warranted.

Marijuana's dose-dependent effects in daily marijuana smokers

Active marijuana produces significant subjective, psychomotor, and physiological effects relative to inactive marijuana, yet demonstrating that these effects are dose-dependent has proven difficult. This within-subject, double-blind study was designed to develop a smoking procedure to obtain a marijuana dose-response function. In four outpatient laboratory sessions, daily marijuana smokers (N = 17 males, 1 female) smoked six 5-s puffs from 3 marijuana cigarettes (2 puffs/cigarette). The number of puffs from active (≥5.5% Δ⁹-tetrahydrocannabinol/THC) and inactive (0.0% THC) marijuana varied according to condition (0, 2, 4, or 6 active puffs); active puffs were always smoked before inactive puffs. Subjective, physiological, and performance effects were assessed prior to and at set time points after marijuana administration. Active marijuana dose-dependently increased heart rate and decreased marijuana craving, despite evidence (carbon monoxide expiration, weight of marijuana cigarettes post-smoking) that participants inhaled less of each active marijuana cigarette than inactive cigarettes. Subjective ratings of marijuana "strength," "high," "liking," "good effect," and "take again" were increased by active marijuana compared with inactive marijuana, but these effects were not dose-dependent. Active marijuana also produced modest, non-dose-dependent deficits in attention, psychomotor function, and recall relative to the inactive condition. In summary, although changes in inhalation patterns as a function of marijuana strength likely minimized the difference between dose conditions, dose-dependent differences in marijuana's cardiovascular effects and ratings of craving were observed, whereas subjective ratings of marijuana effects did not significantly vary as a function of dose.

Illicit drug use among pregnant women enrolled in treatment for cigarette smoking cessation

INTRODUCTION

Smoking during pregnancy is the leading preventable cause of poor pregnancy outcomes in the United States. In population studies and nationwide surveys, pregnant smokers report more illicit drug use than pregnant nonsmokers. The purpose of this study was to examine the prevalence of illicit drug use among pregnant women enrolled in clinical trials for smoking cessation.

METHODS

Urine specimens from 115 pregnant women were tested for illicit drug use during a study intake visit (~10th week of pregnancy) and during the final antepartum (FAP) smoking-status assessment (~28th week of pregnancy). Participants smoked about 18 cigarettes/day prepregnancy, were generally young (<25 years), Caucasian, with a high school education and without private insurance.

RESULTS

About 34% of specimens from the intake visit and 25% of those from the FAP assessment tested positive for an illicit drug. The most common drug detected was marijuana (90% of positive specimens), followed by opioids (18%), cocaine (5%), benzodiazepines (3%), and methadone (3%). None tested positive for amphetamines. The majority of women (53%) who tested positive for an illicit substance at intake also tested positive at the FAP assessment.

CONCLUSIONS

Approximately a quarter to a third of pregnant women enrolled in these smoking-cessation trials were determined to be using illicit drugs, with marijuana use being the most prevalent. Those providing smoking-cessation services to pregnant women may want to be prepared to assist with obtaining services for other drug use as well.

The co-occurring use and misuse of cannabis and tobacco: a review

AIMS

  Cannabis and tobacco use and misuse frequently co-occur. This review examines the epidemiological evidence supporting the life-time co-occurrence of cannabis and tobacco use and outlines the mechanisms that link these drugs to each other. Mechanisms include (i) shared genetic factors; (ii) shared environmental influences, including (iii) route of administration (via smoking), (iv) co-administration and (v) models of co-use. We also discuss respiratory harms associated with co-use of cannabis and tobacco, overlapping withdrawal syndromes and outline treatment implications for co-occurring use.

METHODS

  Selective review of published studies.

RESULTS

  Both cannabis and tobacco use and misuse are influenced by genetic factors, and a proportion of these genetic factors influence both cannabis and tobacco use and misuse. Environmental factors such as availability play an important role, with economic models suggesting a complementary relationship where increases in price of one drug decrease the use of the other. Route of administration and smoking cues may contribute to their sustained use. Similar withdrawal syndromes, with many symptoms in common, may have important treatment implications. Emerging evidence suggests that dual abstinence may predict better cessation outcomes, yet empirically researched treatments tailored for co-occurring use are lacking.

CONCLUSIONS

  There is accumulating evidence that some mechanisms linking cannabis and tobacco use are distinct from those contributing to co-occurring use of drugs in general. There is an urgent need for research to identify the underlying mechanisms and harness their potential etiological implications to tailor treatment options for this serious public health challenge.

Characterizing smoking topography of cannabis in heavy users

RATIONALE

Little is known about the smoking topography characteristics of heavy cannabis users. Such measures may be able to predict cannabis use-related outcomes and could be used to validate self-reported measures of cannabis use.

OBJECTIVES

The current study was conducted to measure cannabis smoking topography characteristics during periods of ad libitum use and to correlate topography assessments with measures of self-reported cannabis use, withdrawal and craving during abstinence, and cognitive task performance.

METHODS

Participants (N = 20) completed an inpatient study in which they alternated between periods of ad libitum cannabis use and abstinence. Measures of self-reported cannabis use, smoking topography, craving, withdrawal, and sleep measures were collected.

RESULTS

Participants smoked with greater intensity (e.g., greater volume, longer duration) on initial cigarette puffs with a steady decline on subsequent puffs. Smoking characteristics were significantly correlated with severity of withdrawal, notably sleep quality and architecture, and craving during abstinence, suggesting dose-related effects of cannabis use on these outcomes. Smoking characteristics generally were not significantly associated with cognitive performance. Smoking topography measures were significantly correlated with self-reported measures of cannabis use, indicating validity of these assessments, but topography measures were more sensitive than self-report in predicting cannabis-related outcomes.

CONCLUSIONS

A dose-effect relationship between cannabis consumption and outcomes believed to be clinically important was observed. With additional research, smoking topography assessments may become a useful clinical tool.

Marijuana use and tobacco smoking cessation among heavy alcohol drinkers

BACKGROUND

Whereas problem drinking impedes smoking cessation, less is known whether marijuana use affects smoking cessation outcomes and whether smoking cessation treatment leads to changes in marijuana smoking.

METHODS

In a randomized clinical trial that recruited 236 heavy drinkers seeking smoking cessation treatment, we examined whether current marijuana smokers (n=57) differed from the rest of the sample in tobacco smoking and alcohol use outcomes and whether the patterns of marijuana use changed during treatment.

RESULTS

Half of the marijuana users reported smoking marijuana at least weekly (an average of 42% of possible smoking days), the other half used infrequently, an average of 5% of possible days. There were no significant differences between the marijuana use groups and non-users on smoking outcomes and marijuana use did not predict smoking lapses. All participants made large reductions in weekly alcohol consumption during the trial, with weekly marijuana users reducing their drinking by 47% and at a faster rate than non-marijuana users after the 8-week follow-up. Weekly marijuana smokers also steadily decreased their marijuana use over the course of the study (at 8-, 16-, and 26-week follow-ups) by more than 24%.

CONCLUSIONS

These data suggest that frequent marijuana smokers may benefit from smoking cessation interventions, even when marijuana use is not explicitly discussed. These individuals do not show any more difficulty than other cigarette smokers in making efforts to reduce tobacco smoking and in fact, make meaningful changes in marijuana use and heavy drinking. Future clinical trials should examine whether smoking cessation treatment that addresses both marijuana and tobacco smoking leads to substantial reductions in marijuana use.

Design considerations for a study to evaluate the impact of smoking cessation treatment on stimulant use outcomes in stimulant-dependent individuals

Cigarette smoking is prevalent in cocaine/methamphetamine-dependent patients and associated with significant morbidity and mortality, yet, the provision of smoking cessation treatment in conjunction with substance use disorder (SUD) treatment is not standard practice. This is due, in part, to clinician concern that combining smoking cessation treatment with SUD treatment could lead to poorer SUD outcomes. The NIDA Clinical Trials Network is conducting a 10-week, two-group, randomized trial to evaluate the impact of providing smoking cessation treatment (SCT) with SUD treatment as usual (TAU), compared to TAU alone, in smokers who are in outpatient treatment for cocaine or methamphetamine dependence. Approximately 528 participants, recruited from 12 community treatment programs, will be randomized into the trial. The present paper describes key design decisions made during protocol development. The trial is designed to evaluate the relationship between cigarette smoking and stimulant use, which prior research suggests is linked, and should contribute to our understanding of how best to address the co-occurring problems of nicotine dependence and cocaine/methamphetamine-dependence. Unique aspects of the trial include the primary question of interest, which concerns the impact of providing SCT on SUD outcomes rather than on smoking outcomes, and the intensity of the SCT chosen, which includes bupropion, nicotine replacement, and two psychosocial interventions.

Tobacco and cannabis co-occurrence: does route of administration matter?

BACKGROUND

Qualitative research suggests that a shared route of administration (i.e. via inhalation) for the common forms of both tobacco (i.e. cigarettes) and cannabis (i.e. joints) may contribute to their co-occurring use.

METHODS

We used data on 43,093 U.S. adults who participated in the 2001-2002 National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) to examine whether cannabis use and abuse/dependence were associated with smoked (cigarettes, cigars, pipes) versus smokeless (snuff, chewed tobacco) forms of tobacco use, even after controlling for socio-demographic, psychiatric and substance-related covariates.

RESULTS

Tobacco smoking was associated with a 3.3-4.5 times increased risk for cannabis use and abuse/dependence respectively. After covariate adjustment, importantly for nicotine dependence, smoking tobacco (but not smokeless tobacco) was still significantly associated with both cannabis use (multinomial odds-ratio (MOR) 1.99) and cannabis dependence (MOR 1.55). In contrast, use of smokeless tobacco was not significantly correlated with elevated rates of cannabis use (MOR 0.96) or abuse/dependence (MOR 1.04).

CONCLUSIONS

Route of administration may play an important role in the observed association between tobacco and cannabis use. This may represent a physiological adaptation of the aero-respiratory system and/or index social and cultural influences surrounding the use of smoked versus smokeless forms of tobacco.

Cannabis potency and contamination: a review of the literature

AIMS

Increased potency and contamination of cannabis have been linked in the public domain to adverse mental health outcomes. This paper reviews the available international evidence on patterns of cannabis potency and contamination and potential associated harms, and discusses their implications for prevention and harm reduction measures.

METHODS

A systematic literature search on cannabis potency and contamination was conducted.

RESULTS

Cannabis samples tested in the United States, the Netherlands, United Kingdom and Italy have shown increases in potency over the last 10 years. Some countries have not shown significant increases in potency, while other countries have not monitored potency over time. While there are some grounds to be concerned about potential contaminants in cannabis, there has been no systematic monitoring.

CONCLUSION

Increased potency has been observed in some countries, but there is enormous variation between samples, meaning that cannabis users may be exposed to greater variation in a single year than over years or decades. Claims made in the public domain about a 20- or 30-fold increase in cannabis potency and about the adverse mental health effects of cannabis contamination are not supported currently by the evidence. Systematic scientific testing of cannabis is needed to monitor current and ongoing trends in cannabis potency, and to determine whether cannabis is contaminated. Additionally, more research is needed to determine whether increased potency and contamination translates to harm for users, who need to be provided with accurate and credible information to prevent and reduce harms associated with cannabis use.

Differential responses to cannabis potency: A typology of users based on self-reported consumption behaviour

AIMS

To determine whether a classification of cannabis users into different types can help to clarify the relationship between cannabis potency and consumption behaviour, harmful physical effects and psychological dependency.

METHODS

A field sample of 388 respondents was recruited who had smoked cannabis at least once in the past month. They were contacted and interviewed in 28 cannabis coffee shops located in five Dutch cities. Data were collected with an assisted self-completion questionnaire. Cluster analysis was performed using the k-means method.

FINDINGS

Various ways were observed in which cannabis users in natural settings adjusted their intake to the potency of the drug. Cluster analysis identified three broad types of cannabis users. The strongest high type was the youngest, consumed the highest monthly dose, inhaled higher-potency cannabis more deeply, and scored highest on psychological cannabis dependency. The consistent high type preferred milder cannabis, consumed the lowest monthly dose, and compensated for stronger cannabis by inhaling less deeply and smoking less. The steady quantity type was the oldest, usually smoked alone, consumed an intermediate monthly dose, and did not tend to adjust the depth of inhalation to the potency of the cannabis. The results suggest that this typology might also reflect three successive stages in the careers of continuing cannabis users.

CONCLUSIONS

Laboratory studies to assess the effects of higher THC concentrations on external and internal exposure to cannabis should allow for the possibility that the types of users studied can affect the results.

Analysis of the endocannabinoid system by using CB1 cannabinoid receptor knockout mice

The endocannabinoid system has been involved in the control of several neurophysiological and behavioural responses. To date, three lines of CB1 knockout mice have been established independently in different laboratories. This chapter reviews the main results obtained with these lines of CB1 knockout mice in several physiological responses that have been previously related to the activity of the endocannabinoid system. Studies using CB1 knockout mice have demonstrated that this receptor participates in the control of several behavioural responses including locomotion, anxiety- and depressive-like states, cognitive functions such as memory and learning processes, cardiovascular responses and feeding. Furthermore, the CB1 cannabinoid receptor is involved in the control of pain by acting at peripheral, spinal and supraspinal levels. The involvement of the CB1 cannabinoid receptor in the behavioural and biochemical processes underlying drug addiction has also been investigated. These CB1 knockouts have provided new findings to clarify the interactions between cannabinoids and the other drugs of abuse such as opioids, psychostimulants, nicotine and ethanol. Recent studies have demonstrated that endocannabinoids can function as retrograde messengers, modulating the release of different neurotransmitters, including opioids, gamma-aminobutyric acid (GABA), and cholecystokinin (CCK), which could explain some of the responses observed after the stimulation of the CB1 cannabinoid receptor. This review provides an update of the apparently controversial data reported in the literature using the three different lines of CB1 knockout mice, which seem to be mainly due to the use of different experimental procedures rather than any constitutive alteration in these lines of knockouts.

Self-administration of cannabinoids by experimental animals and human marijuana smokers

Drug self-administration behavior has been one of the most direct and productive approaches for studying the reinforcing effects of psychoactive drugs, which are critical in determining their abuse potential. Cannabinoids, which are usually abused by humans in the form of marijuana, have become the most frequently abused illicit class of drugs in the United States. The early elucidation of the structure and stereochemistry of delta-9-tetrahydrocannabinol (THC) in 1964, which is now recognized as the principal psychoactive ingredient in marijuana, activated cannabinoid research worldwide. This review examines advances in research on cannabinoid self-administration behavior by humans and laboratory animals. There have been numerous laboratory demonstrations of the reinforcing effects of cannabinoids in human subjects, but reliable self-administration of cannabinoids by laboratory animals has only recently been demonstrated. It has now been shown that strong and persistent self-administration behavior can be maintained in experimentally and drug-naïve squirrel monkeys by doses of THC comparable to those in marijuana smoke inhaled by humans. Furthermore, reinforcing effects of some synthetic CB1 cannabinoid agonists have been recently reported using intravenous and intracerebroventricular self-administration procedures in rats and mice. These findings support previous conclusions that THC has a pronounced abuse liability comparable to other drugs of abuse under certain experimental conditions. Self-administration of THC by squirrel monkeys provides the most reliable animal model for human marijuana abuse available to date. This animal model now makes it possible to study the relative abuse liability of other natural and synthetic cannabinoids and to preclinically assess new therapeutic strategies for the treatment or prevention of marijuana abuse in humans.

Transdermal nicotine alters some of marihuana's effects in male and female volunteers

Despite the fact that tobacco and marihuana are often used together, relatively little is known about the effects of this combination. In order to investigate the effects of the principal psychoactive component in tobacco smoke, nicotine, on marihuana-induced intoxication, we conducted a double blind, cross-over experiment using nicotine transdermal patches. Ten male and 10 female participants received either placebo or a 21 mg transdermal nicotine patch 4 h before smoking one of two marihuana cigarettes (1.99 or 3.51% delta-9-tetrahydrocannabinol (Delta(9) THC) content). Measurements of physiological activity (heart rate, blood pressure, and skin temperature) and subjective effects (self-reports of drug effects on visual analog scales (VAS) and the Addiction Research Center Inventory (ARCI)) were made periodically before and for 3h after smoking. Nicotine pre-treatment enhanced several responses to marihuana, in particular, heart rate, reports of "stimulated" on the visual analog scales, and scores on the Amphetamine scale of the ARCI. Male participants reported a more pronounced effect of marihuana that persisted longer than that of the female participants. Compared to the male participants, female participants experienced an attenuated response to marihuana and were less affected by the drug combination. The results of this study show that nicotine can have an important influence on the subjective and physiological effects of smoked marihuana. These effects have implications for the safety and efficacy of marihuana smokers who are self-medicating with the nicotine transdermal patch to manage their tobacco dependence.

Grey lungs and blue moods: smoking cessation in the context of lifetime depression history

OBJECTIVE

To present an overview of the relationship between depression and cigarette smoking and to provide recommendations for clinicians who wish to help patients with a history of depression to stop smoking.

METHOD

English language journal articles published in the last 15 years on clinical material related to depression history, smoking cessation and related health issues were collected via MEDLINE, PsycINFO and Cochrane Library database searches.

RESULTS

Nicotine dependence is associated with increased rates of depression prior to and after taking up smoking as well as increased rates of suicidal ideation. Depression history is associated with increased rates of nicotine dependence, problems with smoking cessation and depression after cessation. While nicotine replacement and counselling are effective for smoking cessation, standard smoking cessation strategies may not pay sufficient attention to the needs of smokers with a depression history. Some antidepressants (bupropion and nortriptyline) are particularly effective for those with a lifetime depression history as they appear to assist with dysphoria during withdrawal and prevent relapse. Psychological and lifestyle strategies, such as motivational interviewing, relaxation exercises and mood charts, assist in mood regulation over and above the standard smoking cessation treatments for smokers with a depression history, who require more attention to relapse of depression and smoking after quitting.

CONCLUSIONS

There is a complex and circular relationship between depression, smoking and medical illness that complicates smoking cessation in those who have a history of depression. Depression-history smokers require a multimodal approach to assist with mood regulation and nicotine withdrawal. Further research is required to identify effective strategies to reduce smoking in this context.

A review of the influence of particle size, puff volume, and inhalation pattern on the deposition of cigarette smoke particles in the respiratory tract

Ventilation of the cigarette was designed to allow dilution of the cigarette smoke and thereby reduce the dose delivered to the smoker. Following the toxicological principle of dose response, a lower concentration of cigarette smoke should be associated with a lower toxicological response. However, there have been many studies reporting on the phenomenon of compensation whereby the smoker increases puff volume and/or frequency in order to obtain higher volumes of smoke This article reviews studies of the particle size of cigarette smoke and examines, based on available literature, the associated differences in the tobacco smoke and smoking behavior and their relationship to deposition patterns in the lung. The data available indicate that particle size of the cigarette smoke does not significantly change as a function of cigarette type or smoking behavior. The cigarette smoke particle size is in the same range as the minimum deposition particle size in the lung. While varying concentrations of particles are taken into the mouth, the subsequent inhalation pattern has been reported as remaining constant and also does not appear to change significantly under different smoking types and conditions. The dynamics of what happens to the smoke in the short time it is retained in the mouth have not been studied, and this perhaps should be the subject of future investigations. The current data therefore suggest that the particle deposition pattern of the smoke within the lung would not change significantly if compensation occurs.

History of marijuana use and tobacco smoking topography in tobacco-dependent adolescents

Adolescent tobacco smokers have higher rates of marijuana (MJ) use than nonsmokers. Because MJ smoking typically involves deeper inhalation and longer breathholding than tobacco smoking, we hypothesized greater puff volume, longer puff duration and puff interval, and higher puff velocity during tobacco smoking among (1) MJ-using teens; (2) teens whose onset of MJ smoking occurred before tobacco (MBT). One hundred and three tobacco-dependent adolescents presented for smoking cessation treatment (66.0% female, 71.0% European American, mean age 15.3+/-1.25 years) smoked one cigarette of their own brand in the laboratory prior to study entry. Topography and associated physiological measures among current recreational (<5 days in a 14-day period) MJ users (n=25), current heavy (>/=5 days in a 14-day period) MJ users (n=22) and current non-MJ-smoking teens (n=56) were compared. There were no differences in tobacco smoking topography or physiological measures by recent MJ-smoking history or by order of substance initiation. Significantly more African American than European American adolescent smokers reported MJ use before tobacco. Our findings in adolescent smokers are consistent with results from adult studies in which history of MJ smoking was not associated with changes in tobacco smoking topography.

Transdermal nicotine maintenance attenuates the subjective and reinforcing effects of intravenous nicotine, but not cocaine or caffeine, in cigarette-smoking stimulant abusers

The effects of transdermal nicotine maintenance on the subjective, reinforcing, and cardiovascular effects of intravenously administered cocaine, caffeine, and nicotine were examined using double-blind procedures in nine volunteers with histories of using tobacco, caffeine, and cocaine. Each participant was exposed to two chronic drug maintenance phases (21 mg/day nicotine transdermal patch and placebo transdermal patch). Within each drug phase, the participant received intravenous injections of placebo, cocaine (15 and 30 mg/70 kg), caffeine (200 and 400 mg/70 kg), and nicotine (1.0 and 2.0 mg/70 kg) in mixed order across days. Subjective and cardiovascular data were collected before and repeatedly after drug or placebo injection. Reinforcing effects were also assessed after each injection with a Drug vs Money Multiple-Choice Form. Intravenous cocaine produced robust dose-related increases in subjective and reinforcing effects; these effects were not altered by nicotine maintenance. Intravenous caffeine produced elevations on several subjective ratings; nicotine maintenance did not affect these ratings. Under the placebo maintenance condition, intravenous nicotine produced robust dose-related subjective effects, with maximal increases similar to the high dose of cocaine; nicotine maintenance significantly decreased the subjective and reinforcing effects of intravenous nicotine. The results of the present study demonstrate that chronic nicotine maintenance produces tolerance to the effects of intravenous nicotine, but does not affect the subjective or reinforcing effects of cocaine or caffeine.

Acute effects of D-amphetamine on progressive-ratio performance maintained by cigarette smoking and money

RATIONALE

Psychomotor stimulants often increase cigarette smoking, although the mechanisms responsible for that effect remain unclear.

OBJECTIVE

The present study was conducted to extend our investigation of the effects of psychomotor stimulant use on the reinforcing effects of cigarette smoking.

METHODS

A progressive-ratio (PR) schedule was used to examine the acute effects of orally administered D-amphetamine (placebo, 5, 10, 15 mg/70 kg) on the reinforcing effects of smoking (2 puffs/ratio) and money (1.00 US dollar/ratio) in 18 adult smokers.

RESULTS

Among the overall sample of 18 smokers, D-amphetamine produced only a modest, non-significant increase in the amount of responding maintained by smoking (PR break point), but effects varied systematically between subjects. D-Amphetamine increased the smoking break point among ten subjects (responders), while leaving unchanged or decreasing the break point in the remaining eight individuals (non-responders). Responders also were more sensitive than non-responders to d-amphetamine's effects on visual-analog ratings of "high", "good effects", "drowsy", and "slurred speech", but not on other subject ratings (i.e., "bad effects", "jittery", "confused") or on any physiological measures (i.e., heart rate, blood pressure, skin temperature). D-Amphetamine did not significantly alter PR break point maintained by money.

CONCLUSIONS

These results provide further evidence that D-amphetamine can increase the reinforcing effects of cigarette smoking, at least among a subset of smokers.

Current perspectives on smoking cessation among substance abusers

The prevalence of nicotine dependence among alcohol or other substance abusers is extremely high, and surveys have revealed that many patients in drug or alcohol treatment programs are interested in smoking cessation. However, smoking cessation has not been a traditional focus in clinical interventions for this population. Recent evidence from clinical trials among individuals abusing alcohol, marijuana, cocaine, or opioids have shown the following: 1) smokers with a past but not current history of alcohol dependence have a similar rate of success compared with non-alcoholic smokers; 2) tobacco abstinence does not increase alcohol relapse; 3) continued smoking adversely affects treatment for marijuana dependence; 4) patterns of cocaine and nicotine use are interrelated; 5) smoking cessation rates among opioid-dependent individuals are several times lower than in the general US population. Smoking cessation is indicated for substance dependent persons already in recovery and may protect against relapse to the illicit drug of abuse.

Marijuana use and cessation of tobacco smoking in adults from a community sample

Tobacco smokers are more likely to use marijuana than those who do not smoke tobacco. Little is known about how marijuana use affects the probability of tobacco smoking cessation. This analysis was based on 431 adults less than 45 years of age who reported recent tobacco smoking in the 1981 baseline interview in the household-based Baltimore Epidemiologic Catchment Area study and were re-interviewed 13 years later. At baseline, 41% of the tobacco smokers reported ever use of marijuana, 27% reported use of marijuana in the previous 30 days, and 9% reported daily use of marijuana for 2 weeks or more in the last 30 days. Marijuana users in the past 30 days at baseline were more likely than nonusers to still be using tobacco at follow-up after adjusting for race, educational level and marital status (OR = 1.94, 95% CI = 1.03, 3.63). Daily use of marijuana at baseline was even more strongly related to continued tobacco smoking 13 years later. Difficulty in tobacco cessation might be considered one of the most important adverse effects of marijuana use. Clinicians working with patients who are trying to stop tobacco smoking may be aided by routinely assessing marijuana use history, particularly with the recent increase in co-smoking of marijuana and tobacco.

Nicotine alters some of cocaine's subjective effects in the absence of physiological or pharmacokinetic changes

Tobacco smoking and cocaine use often co-occurs and the frequency of smoking has been positively correlated with the likelihood of cocaine use. In addition, nicotine pretreatment has been shown to increase the rate of cocaine self-administration in rats and to enhance cue-induced cocaine craving in humans. The present study was conducted to investigate whether nicotine pretreatment via a transdermal patch alters the behavioral, physiological, and pharmacokinetic effects of an acute dose of cocaine in nondependent human volunteers. Seven male tobacco smokers who used cocaine occasionally provided informed consent and participated in this placebo-controlled, four-visit study. Following pretreatment with a transdermal nicotine patch (placebo, 14 mg), subjects were challenged with an acute dose of intranasal cocaine (placebo, 0.9 mg/kg). Nicotine pretreatment attenuated cocaine-induced increases in reports of "high" and "stimulated" and increased the latency to detect cocaine effects and cocaine-induced euphoria. Nicotine did not alter cocaine's effects on heart rate, skin temperature, and blood pressure or plasma cocaine, benzoylecgonine (BE), or ecgonine methylester (EME) concentrations. Our findings indicate that nicotine pretreatment alters some of the positive subjective effects of cocaine in humans without affecting cocaine's effects on physiologic responses or pharmacokinetic profiles.

The relationship of tobacco and marijuana smoking characteristics

In an ongoing study of the pulmonary effects of heavy, habitual marijuana smoking, detailed marijuana and tobacco smoking histories were obtained from 467 adult regular smokers of marijuana and/or tobacco. Frequency and cumulative amounts of tobacco and marijuana smoking were similar for smokers and nonsmokers of tobacco, except that pack-years and cigarettes/day at the time of the interview were both significantly less for tobacco smokers who also smoked marijuana compared those who did not. For all subjects who smoked both substances at any time, changes in tobacco and marijuana smoking amounts after commencement of regular smoking of the other substance were similar for tobacco and marijuana; the existing smoking habit decreased in approximately one third of the subjects and remained the same in slightly more than one half of the subjects. Of the dual smokers, 49% began smoking tobacco before marijuana, while 33% began smoking marijuana first; 85% of marijuana smokers who quit tobacco smoking did so after beginning regular marijuana smoking. Self-reported depth of inhalation and breath-holding time of marijuana smoke were similar for tobacco and non-tobacco smokers; smoking topography for tobacco was also comparable for smokers and non-smokers of marijuana.

Preference for high- versus low-potency marijuana

With many drugs of abuse, humans and other species display a preference for higher doses (or more potent dosage forms) over lower doses (or less potent dosage forms). The present study was designed to determine whether this generalization would hold for marijuana smoking by humans. Twelve regular marijuana smokers participated in two independent and identical choice trials in which, on separate sessions, they first sampled marijuana of two different potencies (0.63% and 1.95% delta-9-tetrahydrocannabinol; THC) and then, on the next session, chose which of the two, as well as how much, to smoke. During sampling sessions, the high-potency marijuana produced a greater heart rate increase and greater subjective effects than the low-potency marijuana. Subjects chose the high-potency marijuana significantly more often than the low-potency marijuana (21 out of 24 choice occasions). These results support the hypothesis that the reinforcing effects of marijuana, and possibly its abuse liability, are positively related to THC content.

Variability in subjective responses to marijuana: initial experiences of college students

A short self-report questionnaire that probed initial and most recent experiences with marijuana was administered to 197 undergraduate psychology students. Measures of Global Positive and Global Negative responses to marijuana use were obtained. There was substantial variability in the response to marijuana on both of these scales, which were moderately correlated with each other. The self-reported Global Positive score for initial use of marijuana was correlated with latency to next use of marijuana and with lifetime use of the drug, suggesting that abuse potential of the drug is related to magnitude of initial positive effect. Self-reported Global Negative scores for initial use did not correlate with either of these outcome measures. These data are compared and contrasted to those from a study that examined these responses to cocaine. The findings suggest that the abuse potential for both of these drugs is related to the magnitude of the positive response to first use.

Behavioral effects of cocaine alone and in combination with ethanol or marijuana in humans

Intranasal cocaine (COC) and oral ethanol (ETOH) were administered to one group of seven research volunteers during daily experimental sessions. Following the determination of baseline subjective and performance measures, an ETOH cocktail (0, 19.4, 38.7 or 58.1 g of ETOH in lemonade) was consumed over a 10-min period. COC hydrochloride (4, 48, 96 mg) was inhaled 35-min after the start of ETOH drinking. In a separate experiment, seven research volunteers received intravenous cocaine and smoked marijuana (MJ), alone and in combination during daily experimental sessions. Following the determination of baseline measures, a 1-g MJ cigarette (0-2.7% delta 9-THC, w/w) was smoked and 13 min after the start of MJ smoking COC hydrochloride (0, 16, 32 mg) was given intravenously. ETOH increased simple-reaction time and decreased DSST trials. COC decreased DSST trials, increased incorrect responses on a list-learning task and attenuated the effect of ETOH on DSST performance. Only combinations of the high COC dose and the high MJ dose increased errors on a repeated acquisition task. Intranasal COC increased ratings of 'Stimulated,' and 'High' and LSD scores on the ARCI which were unaffected by ETOH. Increased ratings of 'Sedated' following ETOH alone were attenuated by intranasal (i.n.) COC. Intravenous COC and smoked MJ alone both increased ratings of 'Stimulated' and 'High.' There was a trend for combinations of i.v. COC and MJ to prolong these elevations. The results suggest that the interactive effects of COC in combination with ETOH or MJ, after acute administration, are subtle and in need of further analyses to better understand polydrug abuse.

Patterns of alcohol, cigarette, and caffeine and other drug use in two drug abusing populations

Relationships were explored among the frequencies of use of various drugs by a sample of drug-abusing clients of the Addiction Research Foundation (ARF) in Toronto and by drug abusers volunteering to participate in research at the Addiction Research Center (ARC) in Baltimore. The two groups of drug-abusing individuals differed in a number of characteristics. Those from ARF were admitted primarily for diagnosis and possible treatment for alcohol and non-opioid drug problems, whereas those from the ARC were admitted for participation in research on other drugs of abuse, primarily involving opioids. Patterns of use of certain drugs tended to covary in both groups. Of particular interest was the finding that severity of alcoholism was directly related to various measures of tobacco and caffeinated beverage use. In contrast, there was little correlation between the frequency of use among other drugs of abuse (e.g., heroin, cannabis, glue) and the use of tobacco and caffeine. These findings suggest that dependence on nicotine, caffeine, and alcohol may be governed by the same factors and possibly should be considered jointly in the treatment of alcoholic persons. Frequency of use of other drugs examined may be controlled by other factors than those which determine level of use of tobacco and caffeine.

Nicotine and caffeine use in cocaine-dependent individuals

Nicotine and caffeine use in 87 cocaine-dependent persons seeking treatment at an outpatient clinic were compared to use of those substances in a matched general population sample (n = 78). The prevalence of cigarette smoking was significantly greater in the cocaine-dependent sample (75% vs. 22%). Within the cocaine-dependent sample, smokers were younger, less educated, employed in lesser skilled jobs, and reported an earlier onset and more frequent use of cocaine. The prevalence of caffeine use was significantly less in the cocaine-dependent group (68% vs. 83%), although, among caffeine users, the cocaine group drank significantly more caffeinated beverages per day than matched controls (4.9 vs. 3.3). Interestingly, regular caffeine use was associated with less frequent cocaine use within the cocaine-dependent sample. To our knowledge, this study is the first to report on prevalence of smoking and caffeine use among cocaine-dependent individuals, and suggests that use of these other substances may influence the onset and pattern of cocaine use.

Tar, CO and delta 9THC delivery from the 1st and 2nd halves of a marijuana cigarette

Previous in vitro studies suggest that, with successive puffs from a marijuana cigarette, delta-9-THC becomes concentrated in the remaining uncombusted portion of the cigarette. These observations are consistent with the common practice of smoking marijuana cigarettes to a smaller butt length than that to which tobacco cigarettes are smoked. The purpose of the present study was to compare the delivery of delta-9-THC, as well as total insoluble smoke particulates (tar) and carbon monoxide, from the distal ("first") versus the proximal ("second") halves of a standard marijuana cigarette during "natural" smoking of marijuana. On 4 separate days, ten habitual marijuana users smoked nearly all or approximately 1/2 of a standard marijuana cigarette (83 mm length; 800-900 mg; 1.24% THC), as follows: day 1, "whole" cigarette (60 mm smoked, leaving a 23-mm butt); day 2, "first" half (first 30 mm); day 3, "second" half (second 30 mm) after the "first" half was presmoked with a syringe; and day 4, "second" half after the "first" half was excised. A previously described smoking apparatus (20) was used for measurement of puff volume and inhaled tar. Puff volume and number were allowed to vary spontaneously (provided that the specified length of cigarette was consumed), while inhaled volume (1.5 liters), breathholding time (14 s) and interpuff interval (30 s) were held constant. Blood samples were withdrawn prior to smoking and serially after completion of smoking for analysis of blood carboxyhemoglobin (COHb) and serum delta-9-THC. Heart rate was measured before and 5 min after smoking. Subjects rated their level of "high" 20 min after completion of smoking.(ABSTRACT TRUNCATED AT 250 WORDS)

Multidimensional behavioral effects of marijuana

1. Five groups of three healthy adult male volunteers (n = 15), all reporting occasional, controlled marijuana use, gave written consent and participated in residential studies lasting 6 to 15 days. 2. Subjects smoked marijuana cigarettes (0, 1.3, 2.3 or 2.7% THC, w/w) at 0945, 1330, 1700 and 2030 every day, and each subject received both active and placebo marijuana cigarettes in 2-5 consecutive day phases, with placebo and active doses presented in an alternating fashion. 3. In comparison with placebo, active marijuana produced a variety of effects on measures of human behavior, including increases in food consumption and errors on psychomotor tasks, decreases in bouts of tobacco-cigarette smoking and verbal interactions and no changes in rates of task performance, time spent under social conditions or social cooperation. 4. Dimensions of human behavior were differentially sensitive to the effects of smoked marijuana. 5. The simultaneous measurement of multiple dimensions of human behavior is a useful procedure for determining dose potency following marijuana administration.

Effects of tetrahydrocannabinol content on marijuana smoking behavior, subjective reports, and performance

This study investigated the smoking topography of marijuana and its effect on heart rate, subjective reports, and cognitive/psychomotor task performance. Male subjects (N = 12) with histories of moderate marijuana use smoked ad lib one cigarette containing 0, 1.3, or 2.7% delta 9-THC on separate days. Smoking topography measures revealed smaller puff and inhalation volumes and shorter puff duration for the high marijuana dose compared to the low dose. No other smoking behavior differed between the active doses. Heart rate was increased dose dependently over placebo levels. Active marijuana also increased subjective reports of drug effect over placebo, but not dose dependently. Significant memory impairment was observed on a forward and reverse digit span task, and performance was impaired on the digit symbol substitution task by the high, but not low, dose of marijuana. Performance on a divided attention task was not affected by marijuana. Thus, although subjects adjusted their smoking of cigarettes varying in THC content, dose-related effects of marijuana were obtained on several measures. The observed differences and individual variation in smoking topography measures suggest that precise control of smoking behavior would improve the accuracy of marijuana dose delivery.

Delta-9-tetrahydrocannabinol content and human marijuana self-administration

The role of marijuana delta-9-tetrahydrocannabinol (THC) content in controlling marijuana smoking behavior was examined in ten regular marijuana smokers. Each subject was allowed to self-administer marijuana of low, medium or high THC content freely over a 30-min period. Each potency of marijuana was color coded, and subjects smoked each potency on five separate occasions to provide the opportunity for them to learn from prior exposures the relative potencies of each marijuana type. Total intake of marijuana smoke during each session was estimated by measuring the post-smoking increase in expired air carbon monoxide (CO) level. Measures of marijuana effect included heart rate and standardized subjective effects scales. There were no differences among the three potencies of marijuana in post-smoking CO boost, and all measures that were sensitive to marijuana showed a clear dose response. Tolerance was observed over the course of the study to the heart-rate increasing effect of marijuana. These results indicate that subjects failed to regulate their intake of marijuana smoke in response to substantial (4-fold) changes in marijuana THC content.

Alcohol and marijuana: comparative dose effect profiles in humans

This study compared subjective and performance dose effect profiles of oral alcohol and smoked marijuana. Male subjects (N = 6) with histories of moderate alcohol and marijuana use received three doses of alcohol (0, 0.6, 1.2 g/kg) and three doses of marijuana (0, 1.3, 2.7% delta 9-THC) in a double-blind, randomized crossover design. Physiological indices indicated that active drug was delivered to subjects dose dependently. Alcohol produced dose-related elevations on several subjective measures of drug effect. The high dose of alcohol impaired performance on circular lights, tracking and digit-symbol substitution (DSST) tasks, whereas the low alcohol dose impaired only circular lights performance. Marijuana produced elevations on subjective report measures, but effects were similar for the two active doses. Minimal performance impairment was seen with marijuana on only one measure (DSST speed). The subjective and performance effect profiles produced by smoked marijuana were similar to that of the low (0.6 g/kg) dose of alcohol. These data are useful for understanding the relative performance impairment produced by alcohol and marijuana and the relationship between their subjective and behavioral effects.

Pharmacological treatment of tobacco dependence

Pharmacologically based approaches for the treatment of tobacco dependence are reviewed. The rational basis for pharmacologic treatment approaches is that tobacco dependence is partially, and critically, mediated by the actions of tobacco-delivered nicotine to the central nervous system. These actions include direct reinforcing properties of nicotine itself, tolerance and physiologic dependence, possible beneficial effects of nicotine in the alleviation of anxiety and control of weight, and neurohormonal regulation which can become important to the maintenance of emotional well-being and performance at work. Insofar as tobacco abstinence leads to negative consequences, via these biobehavioral mechanisms, pharmacologic intervention should be able to assist in initial tobacco detoxification and help tobacco abstinent persons to avoid subsequent relapse. The purpose of this review is to survey some of the efforts to develop such interventions, as well as to elucidate some of the issues relevant to such development. Four distinct approaches are discussed: (1) Nicotine replacement, in which physiologic dependence is transferred to a safer and more therapeutically manageable nicotine delivering formulation; this category includes nicotine polacrilex gum; (2) Blockade therapy, in which a drug is taken that blocks the reinforcing properties of nicotine should relapse occur; (3) Nonspecific pharmacotherapy, in which the biobehaviorally mediated correlates of tobacco abstinence are treated on a symptomatic basis; (4) Deterrent therapy, in which a drug is taken prior to smoking such that any tobacco use would produce reliable aversive effects.

Alcohol use across the menstrual cycle among marihuana users

Thirty women completed alcohol, marihuana, and tobacco use diaries and Form T of the Moos Menstrual Distress Questionnaire (MDQ) every day for three consecutive menstrual cycles. A 99.0% response rate was obtained: 2750 of a possible 2778 diaries were returned. Women reported drinking an average of 1.2 (+/- 1.9) alcoholic drinks per day (range for individuals: 2.7 [+/- 1.7] to 0.2 [+/- 0.5]). Frequency of alcohol use was unrelated to menstrual cycle phase. Seven of the 8 MDQ factors were significantly (p less than 0.04 to p less than 0.001) but weakly related to alcohol use: distress and alcohol use were positively related. There was a significant relationship between tobacco and alcohol use in 11 subjects who smoked at least half a pack of tobacco cigarettes per day but not in 10 occasional smokers. Further, heavier drinkers were considerably more likely to smoke tobacco than were more moderate drinkers. These data indicate that in the absence of severe premenstrual distress, menstrual cycle phase is not a good predictor of alcohol use among female social drinkers.

Nicotine gum: dose-related effects on cigarette smoking and subjective ratings

The effects of nicotine-containing chewing gum on cigarette smoking and subjective and physiological response were evaluated in eight normal volunteers. Isolated subjects smoked their regular brand of cigarettes freely in a naturalistic laboratory environment while watching television or reading. Before 90-min smoking sessions subjects chewed two pieces of placebo or nicotine-containing gum (0, 2, 4, or 8 mg) under double-blind conditions. Each subject received each treatment four times in a mixed order across days. Analysis of the chewed gum for remaining nicotine revealed that the mean delivered nicotine doses were 0, 1.02, 2.39, and 5.20 mg nicotine. Nicotine preloading produced dose-related increases in plasma nicotine, while producing dose-related decreases in various measures of cigarette smoking including number of cigarettes smoked, number of puffs taken, expired air carbon monoxide level, and ratings of smoking satisfaction. Nicotine preloading produced dose-related increases in ratings of gum dose-strength, while producing decreases in ratings of gum dose acceptability and liking. Heart rate and blood pressure were not significantly affected by nicotine gum. Taken together, the present results confirm that responses to nicotine in the gum preparation are orderly and related to dose, and the results suggest that the efficacy of treating tobacco dependence with nicotine gum may be enhanced by increasing the administered dose.