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In our recent article, together with more than 60 of our colleagues, we outlined a proposal for drug policy reform consisting of four specific yet interrelated strategies: (1) de jure decriminalization of all psychoactive substances currently deemed illicit for personal use or possession (so-called “recreational” drugs), accompanied by harm reduction policies and initiatives akin to the Portugal model; (2) expunging criminal convictions for nonviolent offenses pertaining to the use or possession of small quantities of such drugs (and releasing those serving time for these offenses), while delivering retroactive ameliorative relief; (3) the ultimate legalization and careful regulation of currently illicit drugs; and (4) the delivery of a new “Marshall Plan” focused on community-building initiatives, expanded harm reduction programs, and social and health care support efforts (Earp et al. 2021). We were gratified to see so many thoughtful commentaries on our proposal, and we respond to them in part in this reply.

BACKGROUND AND AIMS Stimulant drug users have a greater prevalence of risky driving behaviour. This study aimed to assess how far this association remains after adjusting for aggressiveness. DESIGN Cross-sectional interview study assessing associations between measures of risky driving behaviours as outcomes, measures of stimulant drug use as predictors and a measure of aggressiveness as a covariate. SETTING United States. PARTICIPANTS Data were drawn from wave 3 (2012-13) of the National Epidemiological Survey on Alcohol and Related Conditions (NESARC-III) (n = 36 309 aged ≥ 18 years). MEASUREMENTS Stimulant drug use, past-year DSM-5 stimulant use disorder, aggression and measures of risky driving were assessed using face-to-face interviews conducted using the Alcohol Use Disorder and Associated Disabilities Interview Schedule (AUDADIS-5) and the Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5). FINDINGS Overall, 2714 (8.3%) respondents indicated life-time stimulant use, and 112 (0.3%) met criteria for past-year DSM-5 stimulant use disorder. More than 10% of ongoing stimulant users and one-third of respondents with DSM-5 stimulant use disorder reported stimulant-specific driving under the influence of drugs (DUID) in the past-year (both P

The relationship between amphetamine use and aggressive or violent behaviour is unclear. This review examined laboratory data collected in humans, who were administered an acute dose of amphetamine or methamphetamine, in order to investigate the link between amphetamines and aggression. It is registered with PROSPERO (CRD42019127711). Included in the analysis are data from twenty-eight studies. Behavioural and/or subjective measures of aggression were assessed in one thousand and sixty-nine research participants, with limited amphetamine-use histories, following a single amphetamine dose (0-35 mg). The available published evidence indicates that neither amphetamine nor methamphetamine acutely increased aggression as assessed by traditional laboratory measures. Future research should assess supratherapeutic amphetamine doses as well as include a broader range of multiple aggression measures, facilitating simultaneous assessment of the various components that comprise this complex, multifaceted construct.

Objectives Recently, driven largely by opioid-related deaths, President Donald Trump proclaimed that the opioid problem was now a national emergency. What looks like a radical shift to a more compassionate drug policy-one that favors treatment over incarceration-has encouraged many to hope that there will be far fewer drug-related arrests and deaths than there were in previous decades. Methods and results We present evidence showing that large numbers of drug-related arrests persist and that racial discrimination is evident in opioid-related arrests. In addition, conventional strategies implemented to address opioid-related deaths have proven inadequate. Conclusions We propose solutions grounded in reason and evidence rather than moralism. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Individuals who work nonstandard schedules, such as rotating or night shifts, are more susceptible to workplace injuries, performance decrements, and reduced productivity. This population is also almost twice as likely to use illicit drugs as individuals working a standard day shift. The purpose of this study was to examine the effects of smoked marijuana on performance, mood, and sleep during simulated shift work. Ten experienced marijuana smokers completed this 23-day, within-participant residential study. They smoked a single marijuana cigarette (0, 1.9, 3.56% Δ9-THC) one hour after waking for three consecutive days under two shift conditions: day shift and night shift. Shifts alternated three times during the study, and shift conditions were separated by an ‘off’ day. When participants smoked placebo cigarettes, psychomotor performance and subjective-effect ratings were altered during the night shift compared to the day shift: performance (e.g., vigilance) and a few subjective ratings were decreased (e.g., “Self-Confident”), whereas other ratings were increased (e.g., “Tired”). Objective and subjective measures of sleep were also disrupted, but to a lesser extent. Marijuana attenuated some performance, mood, and sleep disruptions: participants performed better on vigilance tasks, reported being less miserable and tired and sleep a greater number of minutes. Limited negative effects of marijuana were noted. These data demonstrate that abrupt shift changes produce performance, mood, and sleep decrements during night shift work and that smoked marijuana containing low to moderate Δ9-THC concentrations can offset some of these effects in frequent marijuana smokers.

Pharmacotherapy and behavioral treatments for alcohol use disorder are limited in their effectiveness, and new treatments with innovative mechanisms would be valuable. In this pilot study, the authors tested whether a single subanesthetic infusion of ketamine administered to adults with alcohol dependence and engaged in motivational enhancement therapy affects drinking outcomes.Participants were randomly assigned to a 52-minute intravenous administration of ketamine (0.71 mg/kg, N=17) or the active control midazolam (0.025 mg/kg, N=23), provided during the second week of a 5-week outpatient regimen of motivational enhancement therapy. Alcohol use following the infusion was assessed with timeline followback method, with abstinence confirmed by urine ethyl glucuronide testing. A longitudinal logistic mixed-effects model was used to model daily abstinence from alcohol over the 21 days after ketamine infusion.Participants (N=40) were mostly middle-aged (mean age=53 years [SD=9.8]), predominantly white (70.3%), and largely employed (71.8%) and consumed an average of five drinks per day prior to entering the study. Ketamine significantly increased the likelihood of abstinence, delayed the time to relapse, and reduced the likelihood of heavy drinking days compared with midazolam. Infusions were well tolerated, with no participants removed from the study as a result of adverse events.A single ketamine infusion was found to improve measures of drinking in persons with alcohol dependence engaged in motivational enhancement therapy. These preliminary data suggest new directions in integrated pharmacotherapy-behavioral treatments for alcohol use disorder. Further research is needed to replicate these promising results in a larger sample.

Research has suggested that subanesthetic doses of ketamine may work to improve cocaine-related vulnerabilities and facilitate efforts at behavioral modification. The purpose of this trial was to test whether a single ketamine infusion improved treatment outcomes in cocaine-dependent adults engaged in mindfulness-based relapse prevention.Fifty-five cocaine-dependent individuals were randomly assigned to receive a 40-minute intravenous infusion of ketamine (0.5 mg/kg) or midazolam (the control condition) during a 5-day inpatient stay, during which they also initiated a 5-week course of mindfulness-based relapse prevention. Cocaine use was assessed through self-report and urine toxicology. The primary outcomes were end-of-study abstinence and time to relapse (defined as first use or dropout).Overall, 48.2% of individuals in the ketamine group maintained abstinence over the last 2 weeks of the trial, compared with 10.7% in the midazolam group (intent-to-treat analysis). The ketamine group was 53% less likely (hazard ratio=0.47; 95% CI=0.24, 0.92) to relapse (dropout or use cocaine) compared with the midazolam group, and craving scores were 58.1% lower in the ketamine group throughout the trial (95% CI=18.6, 78.6); both differences were statistically significant. Infusions were well tolerated, and no participants were removed from the study as a result of adverse events.A single ketamine infusion improved a range of important treatment outcomes in cocaine-dependent adults engaged in mindfulness-based behavioral modification, including promoting abstinence, diminishing craving, and reducing risk of relapse. Further research is needed to replicate these promising results in a larger sample.

Repeated drug consumption may progress to problematic use by triggering neuroplastic adaptations that attenuate sensitivity to natural rewards while increasing reactivity to craving and drug cues. Using an established laboratory model aimed at evaluating behavioral shifts in the salience of cocaine now vs. money later, we evaluated the effect on cocaine use of a single sub-anesthetic dose of the N-methyl-D-aspartate receptor antagonist ketamine, which converging evidence suggests may work to correct problematic neuroadaptations and restore motivation for non-drug rewards. We found that ketamine, as compared to the control, significantly decreased cocaine self-administration by 67% relative to baseline at greater than 24 hours post-infusion, the most robust reduction observed to date in human cocaine users and the first to involve mechanisms other than stimulant or dopamine agonist effects. These findings signal new directions in medication development for substance use disorders.

In September, 2015, the member states of the UN endorsed Sustainable Development Goals (SDGs) for 2030, which aspire to human-rights-centred approaches to ensuring the health and wellbeing of all people. The SDGs embody both the UN Charter values of rights and justice for all and the responsibility of states to rely on the best scientific evidence as they seek to better humankind. In April, 2016, these same states will consider control of illicit drugs, an area of social policy that has been fraught with controversy and thought of as inconsistent with human rights norms, and in which scientific evidence and public health approaches have arguably had too limited a role.The previous UN General Assembly Special Session (UNGASS) on drugs in 1998—convened under the theme, “A drug-free world—we can do it!”—endorsed drug-control policies with the goal of prohibiting all use, possession, production, and trafficking of illicit drugs. This goal is enshrined in national laws in many countries. In pronouncing drugs a “grave threat to the health and wellbeing of all mankind”, the 1998 UNGASS echoed the foundational 1961 convention of the international drug-control regime, which justified eliminating the “evil” of drugs in the name of “the health and welfare of mankind”. But neither of these international agreements refers to the ways in which pursuing drug prohibition might affect public health. The war on drugs and zero-tolerance policies that grew out of the prohibitionist consensus are now being challenged on multiple fronts, including their health, human rights, and development impact.The Johns Hopkins–Lancet Commission on Drug Policy and Health has sought to examine the emerging scientific evidence on public health issues arising from drug-control policy and to inform and encourage a central focus on public health evidence and outcomes in drug-policy debates, such as the important deliberations of the 2016 UNGASS on drugs. The Commission is concerned that drug policies are often coloured by ideas about drug use and dependence that are not scientifically grounded. The 1998 UNGASS declaration, for example, like the UN drug conventions and many national drug laws, does not distinguish between drug use and drug misuse. A 2015 report by the UN High Commissioner for Human Rights, by contrast, emphasised that drug use “is neither a medical condition, nor does it necessarily lead to drug dependence”. The idea that all drug use is dangerous and evil has led to enforcement-heavy policies and has made it difficult to see potentially dangerous drugs in the same light as potentially dangerous foods, tobacco, and alcohol, for which the goal of social policy is to reduce potential harms.

There have been mixed findings assessing the impact of regular cocaine use on cognitive functioning. This study employed a comprehensive cognitive battery to compare the performance of individuals diagnosed with a cocaine use disorder (N = 3 abusers, N = 17 dependent) against the performance of two control groups: (a) non-drug-users, and (b) marijuana users who report no cocaine use (N = 7 marijuana abusers, N = 0 dependent, N = 13 marijuana users with no Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition, DSM-IV, diagnosis).This one-session, between-participants, outpatient study was conducted at the New York State Psychiatric Institute. Sixty research volunteers completed the study. Drug users in both groups had no signs of current intoxication, but had a positive urine toxicology-which indicated use within 72 hours in the cocaine use disorder group and within the past 30 days (depending on frequency of use) for the marijuana-using control group. The National Institutes of Health (NIH) Toolbox Cognition Battery was used to assess cognitive functioning across six domains: executive function, attention, episodic memory, working memory, processing speed, and language. Each participant's score was also compared against a normative database adjusted for age.Although the mean cognitive scores for all groups fell within the normal range for all tests, marijuana-using control participants outperformed those with a cocaine use disorder on a cognitive flexibility and language measure.Cognitive functioning of individuals diagnosed with cocaine use disorder was observed to be similar to that of control group participants on the majority of tasks and fell within the normal range when compared against normative data.

Introduction Illicit drug use and nicotine dependence (ND) frequently co-occur. Yet, to date very few studies have examined the role of alcohol and illicit drug use in ND persistence. The objectives of this study were to investigate the relationships between specific classes of drug use, abuse, and dependence and the persistence of ND over time among adults in the United States. Methods Data were drawn from the National Epidemiologic Survey on Alcohol and Related Conditions, a national survey of 34,653U.S. adults interviewed between 2001-2002 and reinterviewed 3 years later. Logistic regression analyses were used to investigate the relationships between various classes of drug use, abuse, and dependence among adults with ND at Wave 1 and the odds for persistent ND at Wave 2. Analyses were adjusted for differences in demographic characteristics, mood/anxiety disorders, alcohol use disorders, and other substance use disorders. Results Lifetime drug use was not associated with significantly increased likelihood for persistent ND. Sedative abuse was associated with increased odds for nicotine persistence, but no other types of drug abuse were predictive of ND persistence, after adjusting for demographics, mood/anxiety, and alcohol use disorders. All types of drug dependence were associated with persistence of ND; the strongest associations emerged between opioid and tranquilizer dependence and persistent ND, while the associations between cannabis and cocaine dependence were no longer significant after adjusting for mood/anxiety disorders. Conclusions Clinicians should take care to evaluate the presence and/or history of drug dependence among patients seeking treatment for smoking cessation. These data suggest that a history of substance dependence predicts increased vulnerability to persistent ND.

Background Cocaine dependence involves problematic neuroadaptations that might be responsive to modulation of glutamatergic circuits. This investigation examined the effects of subanesthetic ketamine infusions on motivation for quitting cocaine and on cue-induced craving in cocaine-dependent participants, 24 hours postinfusion. Methods Eight volunteers with active DSM-IV cocaine dependence not seeking treatment or abstinence were entered into this crossover, double-blind trial. Three 52-min intravenous infusions were administered: ketamine (.41 mg/kg or .71 mg/kg) or lorazepam 2 mg, counterbalanced into three orderings in which ketamine .41 mg/kg always preceded the .71 mg/kg dose. Infusions were separated by 48 hours, and assessments occurred at baseline and at 24 hours postinfusion. Outcomes were change between postinfusion and preinfusion values for: 1) motivation to quit cocaine scores with the University of Rhode Island Change Assessment; and 2) sums of visual analogue scale craving ratings administered during cue exposure. Results Compared with the active control lorazepam, a single ketamine infusion (.41 mg/kg) led to a mean 3.9-point gain in University of Rhode Island Change Assessment ( p = .012), which corresponds to an approximately 60% increase over preceding values. There was a reduction of comparable magnitude in cue-induced craving ( p = .012). A subsequent ketamine infusion (.71 mg/kg) led to further reductions in cue-induced craving compared with the control. Infusions were well-tolerated. Conclusions Subanesthetic ketamine demonstrated promising effects on motivation to quit cocaine and on cue-induced craving, 24 hours postinfusion. Research is needed to expand on these preliminary results and to evaluate the efficacy of this intervention in clinical settings.

Background Despite growing concern about the increased rates of synthetic cannabinoid (SC) use and their effects, only limited data are available that addresses these issues. This study assessed the extent of SC product use and reported effects among a cohort of adult marijuana and tobacco users. Methods A brief telephone interview was conducted with individuals who had given permission to be contacted for future research while screening for a cannabis/nicotine dependence medication development study (NCT01204723). Results Respondents ( N = 42; 88% participation rate) were primarily young adults, male, racially diverse, and high school graduates. Nearly all currently smoked tobacco and cannabis, with 86% smoking cannabis on 5 or more days per week. Nearly all (91%) were familiar with SC products, half (50%) reported smoking SC products previously, and a substantial minority (24%) reported current use (i.e., past month). Despite a federal ban on 5 common SCs, which went into effect on March 1, 2011, a number of respondents reported continued SC product use. Common reasons reported for use included, but were not limited to, seeking a new “high” similar to that produced by marijuana and avoiding drug use detection via a positive urine screen. The primary side effects were trouble thinking clearly, headache, dry mouth, and anxiety. No significant differences were found between synthetic cannabinoid product users (ever or current) and nonusers by demographics or other characteristics. Conclusions Among current marijuana and tobacco users, SC product consumption was common and persisted despite a federal ban. The primary reasons for the use of SC-containing products seem to be to evade drug detection and to experience a marijuana-like high.

Sub-anesthetic ketamine infusions may benefit a variety of psychiatric disorders, including addiction. Though ketamine engenders transient alterations in consciousness, it is not known whether these alterations influence efficacy. This analysis evaluates the mystical-type effects of ketamine, which may have therapeutic potential according to prior research, and assesses whether these effects mediate improvements in dependence-related deficits, 24h postinfusion.Eight cocaine dependent individuals completed this double-blind, randomized, inpatient study. Three counter-balanced infusions separated by 48h were received: lorazepam (2mg) and two doses of ketamine (0.41mg/kg and 0.71mg/kg, with the former dose always preceding the latter). Infusions were followed within 15min by measures of dissociation (Clinician Administered Dissociative Symptoms Scale: CADSS) and mystical-type effects (adapted from Hood's Mysticism Scale: HMS). At baseline and 24h postinfusion, participants underwent assessments of motivation to stop cocaine (University of Rhode Island Change Assessment) and cue-induced craving (by visual analogue scale for cocaine craving during cue exposure).Ketamine led to significantly greater acute mystical-type effects (by HMS) relative to the active control lorazepam; ketamine 0.71mg/kg was associated with significantly higher HMS scores than was the 0.41mg/kg dose. HMS score, but not CADSS score, was found to mediate the effect of ketamine on motivation to quit cocaine 24h postinfusion.These findings suggest that psychological mechanisms may be involved in some of the anti-addiction benefits resulting from ketamine. Future research can evaluate whether the psychoactive effects of ketamine influence improvements in larger samples.

Black Americans are incarcerated at disproportionate rates, largely due to racial differences in the application of drug laws. Human immunodeficiency virus (HIV) prevalence rates among Black Americans are also disproportionately high. Moreover, availability of and access to HIV prevention services in correctional settings are limited. Recognizing that Blacks are at an elevated risk of contracting HIV, and that incarceration worsens health outcomes, this paper addresses the importance of implementing comprehensive prison-based HIV programs and prevention interventions to improve the health of this vulnerable population. In the absence of a vaccine, prevention interventions can serve as an effective method of systematically addressing HIV-related health disparities. Prevention strategies offered within correctional settings provide a unique opportunity to engage a high-risk population when its members may be receptive to behavior modification.

Black men currently comprise a substantial percentage of prisoners in the United States. Drug dependence is common among prison populations, and US prisons are high-risk environments for drug use. Prison drug use exacerbates health problems disproportionately prevalent among Black men and prisoners.The goal of this research was to examine predictors of prison drug use among incarcerated Black men.This study examined drug use within the prison environment in a random sample of 134 Black men incarcerated in maximum-security correctional institution. The Addiction Severity Index (ASI) was used to measure illicit drug use history and the extent to which drug use occurred within the prison environment.Seventy-five percent of the participants reported a history of illicit drug use. Overall, 20% (n 25) of the participants, or 25% of those with a history of drug use, reported using drugs during a time frame consistent with incarceration. Participants with lengthier histories of drug use (OR: 1.1, 95% CI 1.0-1.2) and those who were incarcerated longer (OR: 1.1, 95% CI 1.0-1.2) were more likely to use drugs in prison. Drug use in prison was associated with history of injection drug use and with probation/parole status when arrested.Prisoners are engaging in illicit drug use while incarcerated, suggesting that they could benefit from harm reduction and drug treatment services offered during incarceration.Drug treatment programs that address long-standing addictions and coping mechanisms for lengthy prison stays, specifically, would be especially useful for this population.

3,4-Methylenedioxymethamphetamine (MDMA), the main psychoactive component of the recreational drug ecstasy, is a potent serotonin (5-HT) releaser. In animals, MDMA induces 5-HT depletion and toxicity in 5-HT neurons. The aim of this study was to investigate both presynaptic (5-HT transporter, SERT) and postsynaptic (5-HT(2A) receptor) markers of 5-HT transmission in recently abstinent chronic MDMA users compared with matched healthy controls. We hypothesized that MDMA use is associated with lower SERT density and concomitant upregulation of 5-HT(2A) receptors. Positron emission tomography studies using the SERT ligand [¹¹C]DASB and the 5-HT(2A) receptor ligand [¹¹C]MDL 100907 were evaluated in 13 current and recently detoxified MDMA users and 13 matched healthy controls. MDMA users reported a mean duration of ecstasy use of 8 years, regular exposure, and at least 2 weeks of abstinence before the scans. SERT and 5-HT(2A) receptor availability (binding potential, BP(ND)) were analyzed with a two-tissue compartment model with arterial input function. Current recreational MDMA use was significantly associated with lower SERT BP(ND) and higher 5-HT(2A) receptor BP(ND) in cortical, but not subcortical regions. Decreased SERT BP(ND) was regionally associated with upregulated 5-HT(2A) receptor BP(ND). In light of the animal literature, the most parsimonious interpretation is that repeated exposure to MDMA in humans, even in moderate amounts, leads to damage in 5-HT neuron terminals innervating the cortex. Alterations in mood, cognition, and impulse control associated with these changes might contribute to sustain MDMA use. The reversibility of these changes upon abstinence remains to be firmly established.

Although methamphetamine and alcohol are commonly used together in a binge-like pattern, there is a dearth of empirical data investigating the repeated effects of this drug combination. The current study examined acute and residual mood, performance, and physiological effects of methamphetamine alone, alcohol alone, and the combination. Nine adult male volunteers completed this 20-day within-participant, residential laboratory study. During four 5-day blocks of sessions, participants were administered oral methamphetamine (0, 10 mg) combined with alcohol (0, 0.375, 0.75 g/kg) three times (day 2: AM, day 2: PM, and day 3: PM). Breath alcohol concentrations, cardiovascular, subjective, and cognitive/psychomotor performance effects were assessed before drug administration and repeatedly thereafter. Subjective and objective sleep measures were also assessed; residual effects were assessed on days 3–5 of each block. Following the first drug administration, the methamphetamine–alcohol combination produced greater elevations of heart rate and ratings of “good drug effect” compared to either drug alone. Methamphetamine attenuated alcohol-related performance decrements and feelings of intoxication, whereas alcohol attenuated methamphetamine-related sleep disruptions. By the third administration, many of these effects were significantly diminished, suggesting that participants developed tolerance. Few residual effects were observed. These data show that methamphetamine combined with alcohol produced a profile of effects that was different from the effects of either drug alone. The largely positive effects of the drug combination (i.e., greater euphoria, and fewer performance and sleep disruptions) might explain why these drugs are often used in combination.

Despite their chemical similarities, methamphetamine and 3,4-methylenedioxymethamphetamine (MDMA) produce differing neurochemical and behavioral responses in animals. In humans, individual studies of methamphetamine and MDMA indicate that the drugs engender overlapping and divergent effects; there are only limited data comparing the two drugs in the same individuals.This study examined the effects of methamphetamine and MDMA using a within-subject design.Eleven adult volunteers completed this 13-day residential laboratory study, which consisted of four 3-day blocks of sessions. On the first day of each block, participants received oral methamphetamine (20, 40 mg), MDMA (100 mg), or placebo. Drug plasma concentrations, cardiovascular, subjective, and cognitive/psychomotor performance effects were assessed before drug administration and after. Food intake and sleep were also assessed. On subsequent days of each block, placebo was administered and residual effects were assessed.Acutely, both drugs increased cardiovascular measures and "positive" subjective effects and decreased food intake. In addition, when asked to identify each drug, participants had difficulty distinguishing between the amphetamines. The drugs also produced divergent effects: methamphetamine improved performance and disrupted sleep, while MDMA increased "negative" subjective-effect ratings. Few residual drug effects were noted for either drug.It is possible that the differences observed could explain the differential public perception and abuse potential associated with these amphetamines. Alternatively, the route of administration by which the drugs are used recreationally might account for the many of the effects attributed to these drugs (i.e., MDMA is primarily used orally, whereas methamphetamine is used by routes associated with higher abuse potential).

Zolpidem attenuates shift-change-related sleep and performance disruptions. It is unknown whether these benefits alter the reinforcing effects of the drug during shift work. This study examined zolpidem-related reinforcing effects during simulated shift work. Eleven volunteers (3F, 8M) completed this 16-day within-participant, residential laboratory study. Each day participants were given an opportunity to self-administer oral zolpidem (10 mg) or receive a $1 voucher immediately following a 9-h work period and immediately before going to bed. Participants worked under two shift conditions: (1) during the night shift, participants completed computerized task batteries from 00:30 to 09:30 h and went to bed at 16:00 h and (2) during the day shift, participants completed task batteries from 08:30 to 17:30 h and went to bed at 24:00 h. Shift conditions alternated three times during the study. Despite the fact that sleep, psychomotor performance, and some ratings of mood were disrupted during night-shift work, there was no significant effect of shift on choice to take zolpidem. Overall, participants selected markedly fewer zolpidem doses than monetary vouchers (17% versus 83%). Thus, zolpidem did not serve as a reinforcer even when sleep was disrupted. These data are consistent with previous reports indicating that sedatives produce limited reinforcing effects in individuals without a history of drug abuse.

Rationale Previously, we reported that acute marijuana intoxication minimally affected complex cognitive performance of daily marijuana smokers. It is possible that the cognitive tests used were insensitive to marijuana-related cognitive effects. Objectives In the current study, electroencephalographic (EEG) signals were recorded as daily marijuana users performed additional tests of immediate working memory and delayed episodic memory, before and after smoking marijuana. Methods Research volunteers (N = 24), who reported smoking ∼ 24 marijuana cigarettes/week, completed this study. Participants completed baseline computerized cognitive tasks, smoked a single marijuana cigarette (0%, 1.8%, or 3.9% ∆ 9 -THC w/w), and completed additional cognitive tasks; sessions were separated by at least 72-hours. Cardiovascular and subjective effects were also assessed throughout sessions. Results Overall performance accuracy was not significantly altered by marijuana, although the drug increased response times during task performance and induced a response bias towards labeling “new” words as having been previously seen in the verbal episodic memory task. Marijuana reduced slow wave evoked potential amplitude in the episodic memory task and decreased P300 amplitude and EEG power in the alpha band in the spatial working memory task. Heart rate and “positive” subjective-effect ratings were increased in a ∆ 9 -THC concentration-dependent manner. Conclusions Relative to previous findings with infrequent marijuana users, the frequent users in the current study exhibited similar neurophysiological effects but more subtle performance effects. These data emphasize the importance of taking into account the drug-use histories of research participants and examining multiple measures when investigating marijuana-related effects on cognitive functioning.

The ability to control craving for substances that offer immediate rewards but whose long-term consumption may pose serious risks lies at the root of substance use disorders and is critical for mental and physical health. Despite its importance, the neural systems supporting this ability remain unclear. Here, we investigated this issue using functional imaging to examine neural activity in cigarette smokers, the most prevalent substance-dependent population in the United States, as they used cognitive strategies to regulate craving for cigarettes and food. We found that the cognitive down-regulation of craving was associated with ( i ) activity in regions previously associated with regulating emotion in particular and cognitive control in general, including dorsomedial, dorsolateral, and ventrolateral prefrontal cortices, and ( ii ) decreased activity in regions previously associated with craving, including the ventral striatum, subgenual cingulate, amygdala, and ventral tegmental area. Decreases in craving correlated with decreases in ventral striatum activity and increases in dorsolateral prefrontal cortex activity, with ventral striatal activity fully mediating the relationship between lateral prefrontal cortex and reported craving. These results provide insight into the mechanisms that enable cognitive strategies to effectively regulate craving, suggesting that it involves neural dynamics parallel to those involved in regulating other emotions. In so doing, this study provides a methodological tool and conceptual foundation for studying this ability across substance using populations and developing more effective treatments for substance use disorders.

Researchers have identified the association between the use of cocaine and sexual behavior as an important risk factor for HIV infection and have attempted to elucidate the nature of this association. Several lines of research have suggested that facilitation of sexual behavior during intoxication with cocaine may be because of the direct pharmacological effects of the drug (e.g., increase in sexual desire), whereas others have pointed to the importance of factors related to the context of drug use (e.g., opportunities for sexual behavior, expectations about the effects of the drug, social norms). The present study explored the perceived effects of cocaine and heroin on sexual behavior, as well as the social context of drug use as a function of drug type (cocaine vs. heroin), among 46 inner-city drug users who reported a history of regular use of both crack cocaine and heroin. Results indicated that compared to heroin, cocaine had deleterious effects on participants' perceived sexual desire and performance. Despite such deleterious effects on sexual behavior, cocaine was more frequently used with an intimate partner than heroin. Furthermore, participants did not differ in the extent to which they used the two drugs in other social contexts (e.g., with friends, family, or neighbors). These preliminary results suggest that the relationship between cocaine and sexual behavior, especially among long-term cocaine users, may be facilitated by opportunities for sex that exist in the context of cocaine use, rather than by the pharmacological effects of the drug.

The purpose of this double-blind, randomized, outpatient study was to evaluate the reinforcing and subjective effects of modafinil (200, 400, or 600 mg) in cocaine abusers. Twelve participants (2 female, 10 male) completed this study, consisting of 3 blocks of 7 sessions; each block tested a difference dose of modafinil. During the first 2 sessions of each block, participants "sampled" 1 of the doses of modafinil, and placebo. These doses of modafinil and placebo were available for the subsequent five choice sessions of the block. In each choice session, participants had an opportunity to administer active or placebo capsules. Modafinil administration did not differ from placebo administration, and subjective-effects ratings were not systematically altered as a function of modafinil dose. Results suggest that modafinil does not have abuse liability in cocaine abusers.

A post hoc analysis examined depressive symptoms in regular marijuana smokers interested in nontreatment, laboratory studies, and marijuana-dependent treatment-seekers considering clinical trial participation. Among marijuana-dependent treatment-seeking patients screened for a clinical trial, the mean Beck Depression Inventory Score (BDI) was significantly higher than for marijuana-using volunteers screened for nontreatment laboratory studies. Mean self-reported baseline marijuana use was not significantly different between groups, and BDI score was not correlated with use. Although the methods by which the two groups were selected influenced their characteristics (i.e., treatment-seekers are more likely to be experiencing some degree of clinical distress), it is notable that treatment-seeking, and not marijuana use per se, is associated with significantly higher rates of depression.

The Iowa Gambling task, which typically incorporates hypothetical monetary earnings and losses for performance, has been widely used to measure decision-making in substance abusers. We examined the effects of a cash monetary contingency on Gambling task performance in cocaine abusers and control participants.Twenty-two long-term cocaine smokers who met DSM-IV criteria for cocaine dependence and 24 non-cocaine-using control participants completed this study. Both groups were similar in terms of age, executive function, and self-reported alcohol and marijuana use. All participants performed the Gambling task under two counterbalanced conditions: under one condition, earnings and losses were hypothetical, and under the other condition, earnings and losses were in cash.Condition x group interactions on card selection and task completion time were noted (p0.05). Under the hypothetical payment condition, cocaine abusers selected a greater proportion of cards from disadvantageous decks than advantageous decks (p0.05), but took a similar amount of time to complete the task, relative to control participants. However, under the cash payment condition, no group differences were seen for card selection and cocaine abusers took more time than controls to complete the task (p0.05).The application of tangible consequences improved the decision-making and effort of cocaine abusers on the Gambling task, relative to control participants. These findings underscore the importance of considering population-specific factors (e.g., sensitivity to instructional vs. consequential control) when conducting neuropsychological research in substance abusers.

Methamphetamine attenuates disruptions that occur after changes in work shifts. The reinforcing effects of the drug during shift work have yet to be characterized. This study examined methamphetamine-related mood, performance, and reinforcing effects during simulated shift work. Ten volunteers (four women and six men) completed this 19-day study. Participants were given an opportunity to self-administer oral methamphetamine (10 mg) or receive a $1 voucher before and after an 8-h work period for four consecutive days under two shift conditions: (1) “day shift” in which they went to bed at 2400 hours and woke up at 0800 hours and (2) “night shift” when they went to bed at 1600 hours and woke up at 2400 hours. Thus, participants completed task batteries either from 0815 to 1715 hours or from 0015 to 0915 hours. Shift conditions alternated three times during the study and were separated by an “off” day. Night-shift work disrupted psychomotor task performance and some ratings of mood, especially on the first night. Consistent with this, participants chose to take methamphetamine significantly more often on the first night-shift night compared with the first day-shift day. Regardless of shift condition, however, participants selected markedly more methamphetamine doses before the work period than after it (73% versus 34%). These data show that methamphetamine self-administration occurred more often before work rather than after work, suggesting that the use of stimulants by shift workers may be one strategy employed to meet behavioral demands especially under conditions engendering poor performance, fatigue, and/or sleep disruptions.

In a limited number of studies modafinil has been shown to decrease food intake by laboratory animals and humans. The present study represents a secondary data analysis, in which the effects of modafinil on several measures of food intake were determined in humans living in a residential laboratory during simulated shift work. During this 23-day study, a wide selection of food items and beverages were freely available. During this double-blind, within-participant study, volunteers (N = 11) received oral modafinil dose (0, 200, or 400 mg) 1 h after waking for three consecutive days under two shift conditions: day shift and night shift. Shifts alternated three times during the study, and shift conditions were separated by an "off" day. Modafinil (200, 400 mg) dose-dependently decreased total caloric intake by approximately 18% and approximately 38%, respectively, regardless of shift condition, without selectively altering the proportion of total calories derived from carbohydrate, fat and protein. Ratings of "Hungry" were also significantly decreased by both active doses, but only immediately before the lunch break period. In addition, tolerance to the anorexic effects of modafinil was not apparent, as these effects remained stable across the three days of modafinil dosing. These findings show that modafinil produced clear reductions in food intake and suggest that future prospective studies should examine the drug in obese participants.

Although intranasal methamphetamine abuse has increased, there are no published data investigating the residual effects of the drug under controlled conditions. Thus, the current study examined the residual effects of single-dose intranasal methamphetamine administration on a broad range of behavioral and physiological measures. Non-treatment seeking methamphetamine abusers (n = 11) completed this two-week, in-patient, within-participant, double-blind study. The study consisted of 4 two-day blocks of sessions; each block was separated by at least 24 hrs. At approximately 1000 hrs, on the first day of each block, participants received one of four intranasal methamphetamine doses (0, 12, 25, 50 mg/70 kg). Lights were turned out at 2300 hrs that evening and sleep measures were assessed. On the morning of the second day of each block, methamphetamine plasma levels, cardiovascular measures, mood, subjective reports of the previous evening's sleep, and psychomotor performance were assessed to determine residual drug effects. The larger methamphetamine doses (25 and 50 mg) markedly disrupted subjective measures of that night's sleep and some indices of next-day mood, but only the largest dose (50 mg) dose decreased objective measures of that night's sleep and increased next-day physiological measures. Methamphetamine did not produce any negative residual effects on early next-day performance. Future studies should assess methamphetamine-related residual effects following repeated doses administered over consecutive days.

Interest in the relationship between cannabis use and psychosis has increased dramatically in recent years, in part because of concerns related to the growing availability of cannabis and potential risks to health and human functioning. There now exists a plethora of scientific articles addressing this issue, but few provide a clear verdict about the causal nature of the cannabis-psychosis association. Here, we review recent research reports on cannabis and psychosis, giving particular attention to how each report provides evidence relating to two hypotheses: (1) cannabis as a contributing cause and (2) shared vulnerability. Two primary kinds of data are brought to bear on this issue: studies done with schizophrenic patients and studies of first-episode psychosis. Evidence reviewed here suggests that cannabis does not in itself cause a psychosis disorder. Rather, the evidence leads us to conclude that both early use and heavy use of cannabis are more likely in individuals with a vulnerability to psychosis. The role of early and heavy cannabis use as a prodromal sign merits further examination, along with a variety of other problem behaviors (e.g., early or heavy use of cigarettes or alcohol and poor school performance). Future research studies that focus exclusively on the cannabis-psychosis association will therefore be of little value in our quest to better understand psychosis and how and why it occurs.

Intranasal methamphetamine abuse has increased dramatically in the past decade, yet only one published study has investigated its acute effects under controlled laboratory conditions. Thus, the current study examined the effects of single-dose intranasal methamphetamine administration on a broad range of behavioral and physiological measures. Eleven nontreatment-seeking methamphetamine abusers (two females, nine males) completed this four-session, in-patient, within-participant, double-blind study. During each session, one of four intranasal methamphetamine doses (0, 12, 25, and 50 mg/70 kg) was administered and methamphetamine plasma concentrations, cardiovascular, subjective, and psychomotor/cognitive performance effects were assessed before drug administration and repeatedly thereafter. Following drug administration, methamphetamine plasma concentrations systematically increased for 4 h postdrug administration then declined. Methamphetamine dose dependently increased cardiovascular measures and ‘positive’ subjective effects, with peaks occurring approximately 5–15 min after drug administration, when plasma levels were still ascending. In addition, cognitive performance on less complicated tasks was improved by all active methamphetamine doses, whereas performance on more complicated tasks was improved only by the intermediate doses (12 and 25 mg). These results show that intranasal methamphetamine produced predictable effects on multiple behavioral and physiological measures before peak plasma levels were observed. Of interest is the dissociation between methamphetamine plasma concentrations with cardiovascular measures and positive subjective effects, which might have important implications for potential toxicity after repeated doses.

Objectives Individuals with HIV constitute the largest group using cannabinoids for medicinal reasons; yet, no studies have directly compared the tolerability and efficacy of smoked marijuana and oral dronabinol maintenance in HIV-positive marijuana smokers. This placebo-controlled within-subjects study evaluated marijuana and dronabinol across a range of behaviors: eating topography, mood, cognitive performance, physiologic measures, and sleep. Methods HIV-positive marijuana smokers (n = 10) completed 2 16-day inpatient phases. Each dronabinol (5 and 10 mg) and marijuana (2.0% and 3.9% Delta9-tetrahydrocannabinol [THC]) dose was administered 4 times daily for 4 days, but only 1 drug was active per day, thereby maintaining double-blind dosing. Four days of placebo washout separated each active cannabinoid condition. Results As compared with placebo, marijuana and dronabinol dose dependently increased daily caloric intake and body weight in HIV-positive marijuana smokers. All cannabinoid conditions produced significant intoxication, except for low-dose dronabinol (5 mg); the intoxication was rated positively (eg, "good drug effect") with little evidence of discomfort and no impairment of cognitive performance. Effects of marijuana and dronabinol were comparable, except that only marijuana (3.9% THC) improved ratings of sleep. Conclusions These data suggest that for HIV-positive marijuana smokers, both dronabinol (at doses 8 times current recommendations) and marijuana were well tolerated and produced substantial and comparable increases in food intake.

The impact of regular marijuana use on executive cognitive abilities, including decision making, is not well understood. While cross-sectional studies have suggested that substance abusers exhibit impaired decision making, as assessed by the Iowa Gambling Task, the direct role of marijuana use in the Gambling Task performance of marijuana smokers has not been well defined. In this report, we present data on performance on a modified Gambling Task in experienced marijuana users after they had smoked marijuana under controlled laboratory conditions. A total of 36 marijuana users, who reported smoking approximately 24 marijuana cigarettes per week, completed this 3-session outpatient study. During each session, these volunteers completed the Gambling Task once at baseline and 3 times after smoking a single marijuana cigarette (0.0, 1.8, or 3.9% Delta9-THC). Marijuana cigarettes were administered in a double-blind fashion, and the sequence of Delta9-THC concentration was balanced across volunteers. Marijuana increased the time required to complete the task. However, advantageous card selection and money earned on the task were not disrupted by marijuana. These data are consistent with previous findings that indicated that speed of performance on tests of executive function, but not accuracy, is disrupted in experienced marijuana users during marijuana intoxication.

Previously, we reported that gabapentin, a nonselective gamma-aminobutyric acid agonist, reduced 'positive' subjective effects of cocaine without reducing cocaine self-administration. We speculated that the self-administration procedure used in that study was not sensitive to subtle shifts in the reinforcing effects of cocaine. Thus, this study examined the effects of gabapentin maintenance on cocaine self-administration using a purchase-cocaine choice procedure. During this 48-day inpatient/outpatient study, nontreatment-seeking cocaine abusers (n = 12) were maintained on gabapentin (0, 600, 1200 mg/day); four doses of cocaine (0, 12, 25, 50 mg) were each tested twice under each gabapentin condition. All cocaine testing was conducted while participants were inpatients. Before the start of each session, participants were provided with 25 dollars (five 5 dollar bills, one for each choice opportunity) and smoked the 'sample' cocaine dose once. Subsequently, participants were given five opportunities to purchase the sampled dose of cocaine (at 5 dollars per dose) or to keep 5 dollars for that choice trial. Choice to self-administer cocaine increased significantly with escalating cocaine doses; gabapentin maintenance did not alter choice to self-administer cocaine. These results concur with findings from our previous investigations of gabapentin and with those from a clinical trial examining the effects of larger gabapentin doses on cocaine use by treatment-seeking cocaine-dependent individuals. Together, the data indicate that gabapentin does not show promise as a treatment medication for cocaine dependence.

Methamphetamine use has increased significantly and become a global health concern. Craving is known to predict methamphetamine use and relapse following abstinence. Some have suggested that cravings are automatic, generalized, and uncontrollable, but experimental work addressing these claims is lacking. In two exploratory studies we tested the boundary conditions of methamphetamine craving by asking: (1) is craving specific to users’ preferred route of administration? and (2) can craving be regulated by cognitive strategies? Two groups of methamphetamine users were recruited. In Study 1, participants were grouped by their preferred route of administration (intranasal vs. smoking), and rated their craving in response to photographs and movies depicting methamphetamine use (via the intranasal vs. smoking route). In Study 2, methamphetamine smokers implemented cognitive regulation strategies while viewing photographs depicting methamphetamine smoking. Strategies involved either focusing on the positive aspects of smoking methamphetamine or the negative consequences of doing so – the latter strategy based on treatment protocols for addiction. In Study 1, we found a significant interaction between group and route of administration, such that participants who preferred to smoke methamphetamine reported significantly stronger craving for smoking stimuli, whereas those who preferred the intranasal route reported stronger craving for intranasal stimuli. In Study 2, participants reported significantly lower craving when focusing on the negative consequences associated with methamphetamine use. Taken together, these findings suggest that strength of craving for methamphetamine is moderated by users’ route of administration and can be reduced by cognitive strategies. This has important theoretical, methodological, and clinical implications.

Non-therapeutic research with drugs of abuse in humans is important for a more comprehensive understanding of substance abuse and for the development of more effective treatments. However, the administration of substances from drug classes with abuse potential to human volunteers raises ethical questions regarding potential risk to study volunteers.The purpose of this study was to assess the psychosocial functioning and reported drug-taking behavior of volunteers before and after participating in a residential laboratory study, during which either marijuana, methamphetamine or zolpidem was administered.Twenty-two volunteers were administered Addiction Severity Index (ASI) interviews at intake and approximately six months following their study participation.No significant differences between intake and follow-up assessments were found on any ASI composite or drug/alcohol-taking variable.These preliminary data suggest that participation in residential laboratory studies involving the administration of drugs from classes with abuse potential does not alter subsequent psychosocial functioning or reported drug use.

Despite the fact that rates of cannabis dependence have increased substantially over the past several years, there are no medications approved for the treatment of cannabis dependence. This paper reviews data from recent research on cannabinoids that may be relevant for the development of pharmacotherapies for cannabis dependence. Included in the discussion are findings from studies that have assessed the ability of medications to ameliorate cannabis-related abstinence symptoms in laboratory animals and human research participants. Data from studies that have investigated the effects of pharmacological agents on cannabis self-administration are also reviewed because these data may provide information critical for informing relapse prevention medication development efforts. The majority of published studies evaluating cannabis pharmacotherapies have focused on decreasing withdrawal symptoms: a growing number of medications reduce symptoms in laboratory animals, but the majority of these medications have not been tested in humans. Fewer studies have assessed the effects of potential cannabis treatment medications on cannabinoid-related reinforcing effects. In laboratory animals, only the CB1 cannabinoid antagonist rimonabant has shown promise. In humans, this medication has not been tested on cannabis reinforcing effects. To date, no medication has been shown to alter cannabis self-administration by humans.

Oral Delta-9-tetrahydrocannabinol (Delta(9)-THC; Marinol) is medically available for the treatment of nausea associated with cancer chemotherapy and for wasting syndromes related to HIV/AIDS. Little is known about its reinforcing effects.This study was conducted to characterize the reinforcing effects of oral Delta(9)-THC in experienced marijuana smokers under controlled laboratory conditions.Ten healthy male marijuana users completed this 17-day residential study. On days 2, 6, 10, and 14, at 0900 h, participants received a "sample" oral dose of Delta(9)-THC (0, 10, 20 mg) and an alternative reinforcer, a 2 US dollars voucher (redeemable for cash at study's end). Over the next 3 days, they had 11 opportunities to self-administer either the sampled dose of Delta(9)-THC or to receive a 2 US dollars voucher.Participants chose active Delta(9)-THC (10 and 20 mg) more often than placebo (two selections vs approximately four selections, respectively). However, they chose active Delta(9)-THC on less than 50% of choice opportunities. Both active Delta(9)-THC doses produced significant increases in "positive" subjective effects, impaired psychomotor performance, and increased heart rate, relative to the placebo conditions.These data indicate that oral Delta(9)-THC may have modest abuse liability in experienced marijuana smokers.

Use of cocaine, alcohol, and the two drugs simultaneously is common and the risk of morbidity and mortality associated with these drugs is widely reported. This double-blind, placebo-controlled, randomized study examined gender differences in response to administration of these drugs alone and in combination.Current users of cocaine and alcohol (n = 17) who met diagnostic criteria (DSM-IV) for cocaine dependence and alcohol abuse or dependence (not physiologically dependent on alcohol) and who were not seeking treatment for substance use disorders gave voluntary, written, informed consent to participate in three drug administration sessions:1) four doses of intranasal cocaine (1 mg/kg every 30 min) with oral alcohol (1 g/kg following the initial cocaine dose and a second drink at +60 min (120 mg/kg) calculated to maintain a plasma alcohol concentration of approximately 100 mg/dL; 2)four doses of cocaine and alcohol placebo; 3) cocaine placebo and alcohol. Pharmacokinetics were obtained by serial blood sampling, physiological measurements (heart rate and blood pressure) were obtained with automated equipment, and subjective effects were assessed using visual analog scales over 480 min.Responses to cocaine, alcohol, and cocaine-alcohol were equivalent by gender for most measurements. Women had higher heart rates following alcohol administration (p = .02). Women consistently reported higher ratings for "Feel Good:' a measure of overall mental/physical well-being, for all study conditions, reaching statistical significance for cocaine (p = .05) and approaching significance for alcohol administration (p = .1).Women showed equivalent responses to drug administration with the exception of perception of well-being, which was significantly increased for women. These findings may have implications for differential risk for acute and chronic toxicity in women.

Abstinence following daily marijuana use can produce a withdrawal syndrome characterized by negative mood (eg irritability, anxiety, misery), muscle pain, chills, and decreased food intake. Two placebo-controlled, within-subject studies investigated the effects of a cannabinoid agonist, delta-9-tetrahydrocannabinol (THC: Study 1), and a mood stabilizer, divalproex (Study 2), on symptoms of marijuana withdrawal. Participants (n=7/study), who were not seeking treatment for their marijuana use, reported smoking 6-10 marijuana cigarettes/day, 6-7 days/week. Study 1 was a 15-day in-patient, 5-day outpatient, 15-day in-patient design. During the in-patient phases, participants took oral THC capsules (0, 10 mg) five times/day, 1 h prior to smoking marijuana (0.00, 3.04% THC). Active and placebo marijuana were smoked on in-patient days 1-8, while only placebo marijuana was smoked on days 9-14, that is, marijuana abstinence. Placebo THC was administered each day, except during one of the abstinence phases (days 9-14), when active THC was given. Mood, psychomotor task performance, food intake, and sleep were measured. Oral THC administered during marijuana abstinence decreased ratings of 'anxious', 'miserable', 'trouble sleeping', 'chills', and marijuana craving, and reversed large decreases in food intake as compared to placebo, while producing no intoxication. Study 2 was a 58-day, outpatient/in-patient design. Participants were maintained on each divalproex dose (0, 1500 mg/day) for 29 days each. Each maintenance condition began with a 14-day outpatient phase for medication induction or clearance and continued with a 15-day in-patient phase. Divalproex decreased marijuana craving during abstinence, yet increased ratings of 'anxious', 'irritable', 'bad effect', and 'tired.' Divalproex worsened performance on psychomotor tasks, and increased food intake regardless of marijuana condition. Thus, oral THC decreased marijuana craving and withdrawal symptoms at a dose that was subjectively indistinguishable from placebo. Divalproex worsened mood and cognitive performance during marijuana abstinence. These data suggest that oral THC, but not divalproex, may be useful in the treatment of marijuana dependence.

The effects of zolpidem, a nonbenzodiazepine hypnotic, on psychomotor task performance, subjective effects, and food intake were examined during simulated shift work. Seven participants completed this 23-day, within-participant design, residential laboratory study. They received a single oral zolpidem dose (0, 5, or 10 mg) 1 hr before bedtime for 3 consecutive days under 2 shift conditions: day shift and night shift. When participants received placebo, next-day performance and subjective effects were disrupted, and food intake was decreased during the night shift. Zolpidem improved subjective reports of sleep quality and, to a lesser extent, next-day performance. Next-day mood, however, was worsened by zolpidem. Food intake was unaffected by zolpidem. These data indicate that shift changes produce performance impairments, mood alterations, and decreases in food intake, and that zolpidem attenuates some shift-change-related disruptions.

Rationale. Although smoked marijuana contains at least 60 cannabinoids, Δ9-tetrahydrocannabinol (Δ9-THC) is presumed to be the cannabinoid primarily responsible for many marijuana-related effects, including increased food intake and subjective effects. Yet, there has been no systematic comparison of repeated doses of oral Δ9-THC with repeated doses of smoked marijuana in the same individuals. Objective. To compare the effects of oral Δ9-THC and smoked marijuana in humans under controlled laboratory conditions. Methods. Eleven healthy research volunteers, who reported smoking an average of six marijuana cigarettes per day, completed an 18-day residential study. Marijuana cigarettes (3.1% Δ9-THC, q.i.d.) were smoked or Δ9-THC (20 mg, q.i.d.) was taken orally using a staggered, double-blind, double-dummy procedure for three consecutive days. Four days of placebo administration separated each active drug condition. Psychomotor task performance, subjective effects, and food intake were measured throughout the day. Results. Relative to placebo baseline, oral Δ9-THC and smoked marijuana produced similar subjective-effect ratings (e.g., "high" and "mellow"), although some effects of smoked marijuana were more pronounced and less prone to the development of tolerance. Additionally, participants reported "negative" subjective effects (e.g., "irritable" and "miserable") during the days after smoking marijuana but not after oral Δ9-THC. Both drugs increased food intake for 3 days of drug administration, but had little effect on psychomotor performance. Conclusion. These results indicate that the behavioral profile of effects of smoked marijuana (3.1% Δ9-THC) is similar to the effects of oral Δ9-THC (20 mg), with some subtle differences.

Rationale. The discriminative stimulus effects of N-methyl-D-aspartate (NMDA) antagonists have been assessed in laboratory animals. To date, no published study has assessed their ability to alter methamphetamine-related discriminative stimulus effects in humans. Objective. This study investigated the discriminative stimulus, subjective (e.g. "Good Drug Effect"), psychomotor performance, and cardiovascular effects (e.g. blood pressure) of oral methamphetamine following acute oral memantine (a non-competitive NMDA antagonist) in humans. Methods. Initially, participants were trained to discriminate 10 mg methamphetamine from placebo using a standard two-response procedure (drug versus placebo). Then, the effects of memantine (0, 40 mg) on methamphetamine discrimination were examined across several methamphetamine doses (0, 5, 10, 20 mg) using a novel-response procedure (drug versus placebo versus novel). Results. Following placebo pretreatment, 10 mg methamphetamine produced 99% methamphetamine-appropriate responding and placebo produced 75% placebo-appropriate responding. Following memantine pretreatment, participants responded as if they had been given a novel compound, although memantine did not significantly alter most subjective-effects ratings following methamphetamine. Memantine alone produced "positive" subjective effects and novel drug-appropriate responding. Conclusion. These data indicate that the memantine-methamphetamine combination produced novel discriminative stimulus effects and that memantine produced some stimulant-like subjective effects.

Studies have shown that the Delta(9)-tetrahydrocannabinol (Delta(9)-THC) concentration in marijuana cigarettes is an important factor for the maintenance of marijuana self-administration. Yet, the impact of oral Delta(9)-THC treatment on marijuana self-administration is unknown. Because other agonist therapies have been demonstrated to be effective for the treatment of substance use disorders, the objective of this study was to evaluate the influence of oral Delta(9)-THC maintenance on choice to self-administer smoked marijuana. During this 18-day residential study, 12 healthy research volunteers received one of three doses of oral Delta(9)-THC capsules (0, 10, 20 mg q.i.d.) for 3 consecutive days, followed by 3 consecutive days of matching placebo. The order of active Delta(9)-THC administration was counterbalanced. Each morning, except on days 6, 12, and 18, participants smoked the 'sample' marijuana cigarette (1.8% Delta(9)-THC w/w) and received a $2 voucher (redeemable for cash at study's end). Following the sample, volunteers participated in a four-trial choice procedure during which they had the opportunity to self-administer either the dose of marijuana they sampled that morning or to receive the $2 voucher. Relative to placebo Delta(9)-THC maintenance, participants' choice to self-administer marijuana was not significantly altered by either of the two active Delta(9)-THC maintenance conditions. Some 'positive' subjective drug-effect ratings following the sample marijuana cigarette were reduced: by day 3 of active oral Delta(9)-THC maintenance, participants' rating of 'Good Drug Effect' and 'High' were significantly decreased. Smoked marijuana-related total daily caloric intake was not significantly altered under any maintenance conditions. Finally, the effects of smoked marijuana on psychomotor task performance were only minimally affected by oral Delta(9)-THC maintenance. These data indicate that participants' choice to self-administer marijuana was unaltered by the oral Delta(9)-THC dosing regimen used in the present investigation.

In light of the rapidly changing legal status of marijuana in the U.S., there has been increased interest in the potentially adverse outcomes of heavy marijuana use among young persons. The goal of this study was to investigate frequent marijuana use among undergraduates, and its association with the use of illicit substances, mental health problems, and stress.Undergraduates from one university in the Northeast were surveyed using a questionnaire derived from the American College Health Association-National College Health Assessment (N = 1,776). Logistic regression analyses were used to examine relationships between frequency of marijuana use and other substance use, binge drinking, negative consequences of drinking, mental health problems, and perceived stress. Analyses were adjusted for demographics differences such as gender, race, year in school, and sorority/fraternity membership.Approximately 1 in 12 undergraduates (8.5%) reported using marijuana more than 10 days in the past month. Frequent marijuana use was associated with increased likelihood of other substance use and alcohol-related negative outcomes. Marijuana use was associated with increased reports of anxiety, and frequent use was associated with depression and substance use problems. Perceived stress was not associated with marijuana use.These findings, indicating that frequent use is related to depression, other substance use and negative outcomes, contribute to our understanding of marijuana use among undergraduates. Given the relatively high prevalence of marijuana use among young persons, future studies should seek to uncover potentially causal relationships between frequent marijuana use and a variety of negative outcomes.

Although the ability to perform complex cognitive operations is assumed to be impaired following acute marijuana smoking, complex cognitive performance after acute marijuana use has not been adequately assessed under experimental conditions. In the present study, we used a within-participant double-blind design to evaluate the effects acute marijuana smoking on complex cognitive performance in experienced marijuana smokers. Eighteen healthy research volunteers (8 females, 10 males), averaging 24 marijuana cigarettes per week, completed this three-session outpatient study; sessions were separated by at least 72-hrs. During sessions, participants completed baseline computerized cognitive tasks, smoked a single marijuana cigarette (0%, 1.8%, or 3.9% Delta(9)-THC w/w), and completed additional cognitive tasks. Blood pressure, heart rate, and subjective effects were also assessed throughout sessions. Marijuana cigarettes were administered in a double-blind fashion and the sequence of Delta(9)-THC concentration order was balanced across participants. Although marijuana significantly increased the number of premature responses and the time participants required to complete several tasks, it had no effect on accuracy on measures of cognitive flexibility, mental calculation, and reasoning. Additionally, heart rate and several subjective-effect ratings (e.g., "Good Drug Effect," "High," "Mellow") were significantly increased in a Delta(9)-THC concentration-dependent manner. These data demonstrate that acute marijuana smoking produced minimal effects on complex cognitive task performance in experienced marijuana users.