Validation of the revised Mystical Experience Questionnaire in experimental sessions with psilocybin

The 30-item revised Mystical Experience Questionnaire (MEQ30) was previously developed within an online survey of mystical-type experiences occasioned by psilocybin-containing mushrooms. The rated experiences occurred on average eight years before completion of the questionnaire. The current paper validates the MEQ30 using data from experimental studies with controlled doses of psilocybin. Data were pooled and analyzed from five laboratory experiments in which participants (n=184) received a moderate to high oral dose of psilocybin (at least 20 mg/70 kg). Results of confirmatory factor analysis demonstrate the reliability and internal validity of the MEQ30. Structural equation models demonstrate the external and convergent validity of the MEQ30 by showing that latent variable scores on the MEQ30 positively predict persisting change in attitudes, behavior, and well-being attributed to experiences with psilocybin while controlling for the contribution of the participant-rated intensity of drug effects. These findings support the use of the MEQ30 as an efficient measure of individual mystical experiences. A method to score a "complete mystical experience" that was used in previous versions of the mystical experience questionnaire is validated in the MEQ30, and a stand-alone version of the MEQ30 is provided for use in future research.

A randomized controlled trial of the effects of working memory training in methadone maintenance patients

OBJECTIVE

Working memory impairment in individuals with chronic opioid dependence can play a major role in cognitive and treatment outcomes. Cognitive training targeting working memory shows promise for improved function in substance use disorders. To date, cognitive training has not been incorporated as an adjunctive treatment for opioid dependence.

METHODS

Methadone maintenance patients were randomly assigned to experimental (n=28) or active control (n=28) 25-session computerized training and run in parallel. Cognitive and drug use outcomes were assessed before and after training.

RESULTS

Participants in the experimental condition showed performance improvements on two of four working memory measures, and both groups improved on a third measure of working memory performance. Less frequent drug use was found in the experimental group than in the control group post-training. In contrast to previous findings with stimulant users, no significant effect of working memory training on delay discounting was found using either hypothetical or real rewards. There were no group differences on working memory outcome measures that were dissimilar from the training tasks, suggesting that another mechanism (e.g., increased distress tolerance) may have driven drug use results.

CONCLUSIONS

Working memory training improves performance on some measures of working memory in methadone maintenance patients, and may impact drug use outcomes. Working memory training shows promise in patients with substance use disorders; however, further research is needed to understand the mechanisms through which performance is improved and drug use outcomes are impacted.

Salvinorin-A Induces Intense Dissociative Effects, Blocking External Sensory Perception and Modulating Interoception and Sense of Body Ownership in Humans

BACKGROUND

Salvinorin-A is a terpene with agonist properties at the kappa-opioid receptor, the binding site of endogenous dynorphins. Salvinorin-A is found in Salvia divinorum, a psychoactive plant traditionally used by the Mazatec people of Oaxaca, Mexico, for medicinal and spiritual purposes. Previous studies with the plant and salvinorin-A have reported psychedelic-like changes in perception, but also unusual changes in body awareness and detachment from external reality. Here we comprehensively studied the profiles of subjective effects of increasing doses of salvinorin-A in healthy volunteers, with a special emphasis on interoception.

METHODS

A placebo and three increasing doses of vaporized salvinorin-A (0.25, 0.50, and 1mg) were administered to eight healthy volunteers with previous experience in the use of psychedelics. Drug effects were assessed using a battery of questionnaires that included, among others, the Hallucinogen Rating Scale, the Altered States of Consciousness, and a new instrument that evaluates different aspects of body awareness: the Multidimensional Assessment for Interoceptive Awareness.

RESULTS

Salvinorin-A led to a disconnection from external reality, induced elaborate visions and auditory phenomena, and modified interoception. The lower doses increased somatic sensations, but the highest dose led to a sense of a complete loss of contact with the body.

CONCLUSIONS

Salvinorin-A induced intense psychotropic effects characterized by a dose-dependent gating of external audio-visual information and an inverted-U dose-response effect on body awareness. These results suggest a prominent role for the kappa opioid receptor in the regulation of sensory perception, interoception, and the sense of body ownership in humans.

Topiramate impairs cognitive function in methadone-maintained individuals with concurrent cocaine dependence

Topiramate is being investigated as a potential pharmacotherapy for the treatment of addictive disorders. However, its cognitive side effects raise concerns about its use, especially in populations with cognitive impairment, such as persons with chronic substance use disorders. This study investigated topiramate's cognitive effects in individuals dually dependent on cocaine and opioids as part of a double-blind, randomized, controlled trial of topiramate for cocaine dependence treatment. After 5 weeks of stabilization on daily oral methadone (M = 96 mg), participants were randomized to topiramate (n = 18) or placebo (n = 22). Cognitive testing took place at 2 time points: study weeks 4 through 5 to assess baseline performance and 10 to 13 weeks later to assess performance during stable dosing (300 mg topiramate or placebo). All participants were maintained on methadone at both testing times, and testing occurred 2 hours after the daily methadone plus topiramate/placebo administration. The topiramate and placebo groups did not differ on sex, level of education, premorbid intelligence, methadone dose, or illicit drug use. Topiramate slowed psychomotor and information processing speed, worsened divided attention, reduced n-back working memory accuracy, and increased the false alarm rate in recognition memory. Topiramate had no effects on visual processing, other measures of psychomotor function, risk-taking, self-control, Sternberg working memory, free recall, and metamemory. These findings indicate that topiramate may cause cognitive impairment in this population. This effect may limit its acceptability and use as a treatment in individuals with chronic opioid and cocaine use disorders, among whom preexisting cognitive impairments are common. (PsycINFO Database Record

Classic psychedelic use is associated with reduced psychological distress and suicidality in the United States adult population

Mental health problems are endemic across the globe, and suicide, a strong corollary of poor mental health, is a leading cause of death. Classic psychedelic use may occasion lasting improvements in mental health, but the effects of classic psychedelic use on suicidality are unknown. We evaluated the relationships of classic psychedelic use with psychological distress and suicidality among over 190,000 USA adult respondents pooled from the last five available years of the National Survey on Drug Use and Health (2008-2012) while controlling for a range of covariates. Lifetime classic psychedelic use was associated with a significantly reduced odds of past month psychological distress (weighted odds ratio (OR)=0.81 (0.72-0.91)), past year suicidal thinking (weighted OR=0.86 (0.78-0.94)), past year suicidal planning (weighted OR=0.71 (0.54-0.94)), and past year suicide attempt (weighted OR=0.64 (0.46-0.89)), whereas lifetime illicit use of other drugs was largely associated with an increased likelihood of these outcomes. These findings indicate that classic psychedelics may hold promise in the prevention of suicide, supporting the view that classic psychedelics' most highly restricted legal status should be reconsidered to facilitate scientific study, and suggesting that more extensive clinical research with classic psychedelics is warranted.

Sexual discounting among high-risk youth ages 18-24: implications for sexual and substance use risk behaviors

Youth under 25 show substantial sexual and substance use risk behaviors. One factor associated with risk behaviors is delay discounting, the devaluation of delayed outcomes. This study determined if delay discounting for sexual outcomes is related to sexual risk and substance use among 18-24 year olds. Females (70) and males (56) completed the Sexual Discounting Task, which assessed their likelihood of having unprotected immediate sex versus waiting for sex with a condom, at various delays, with 4 hypothetical sexual partners selected from photographs: the person they most wanted to have sex with, least wanted to have sex with, judged most likely to have a sexually transmitted infection (STI), and judged least likely to have an STI. They also completed instruments assessing HIV knowledge, sexual behaviors, substance use, risk attitudes, inhibition, impulsivity, and sensation-seeking. Condom use likelihood generally decreased with increasing delay. Preference for immediate, unprotected sex was greater for partners whom participants most (vs. least) wanted to have sex with and judged least (vs. most) likely to have an STI. Preference for immediate, unprotected sex in the "most want to have sex with" and "least likely to have an STI" conditions was related to greater lifetime risky sexual partners, lifetime number of unique substances used, disregard of social approval/danger, disinhibition, and sensation/excitement-seeking. Males showed greater likelihood of unprotected sex than females when condom use was undelayed, but delay similarly affected condom use between sexes. Delay discounting should be considered in strategies to minimize youth risk behavior.

Investigation of "bath salts" use patterns within an online sample of users in the United States

"Bath salts" are synthetic stimulant "legal highs" that have recently been banned in the US. Epidemiological data regarding bath salts use are limited. In the present study, 113 individuals in the US reporting use of bath salts completed an anonymous, online survey characterizing demographic, experiential, and psychological variables. Respondents were more often male, 18-24 years old, and Caucasian/White with some college education. Past-year use was typically low (≤ 10 days), but marked by repeated dosing. Intranasal was the most frequently reported administration route and subjective effects were similar to other stimulants (e.g., cocaine, amphetamines). Bath salts use was associated with increased sexual desire and sexual HIV risk behavior, and met DSM-5 diagnostic criteria for disordered use in more than half of respondents. Bath salts use persists in the US despite federal bans of cathinone-like constituents. Self-reported stimulant-like effects of bath salts suggest their use as substitutes for traditional illicit stimulants. Data revealed more normative outcomes vis-à-vis extreme accounts by media and medical case reports. However, indications of product abuse potential and sexual risk remain, suggesting bath salts pose potential public health harm.

Psilocybin-occasioned mystical experiences in the treatment of tobacco addiction

Psilocybin-occasioned mystical experiences have been linked to persisting effects in healthy volunteers including positive changes in behavior, attitudes, and values, and increases in the personality domain of openness. In an open-label pilot-study of psilocybin-facilitated smoking addiction treatment, 15 smokers received 2 or 3 doses of psilocybin in the context of cognitive behavioral therapy (CBT) for smoking cessation. Twelve of 15 participants (80%) demonstrated biologically verified smoking abstinence at 6-month follow-up. Participants who were abstinent at 6 months (n=12) were compared to participants still smoking at 6 months (n=3) on measures of subjective effects of psilocybin. Abstainers scored significantly higher on a measure of psilocybin-occasioned mystical experience. No significant differences in general intensity of drug effects were found between groups, suggesting that mystical-type subjective effects, rather than overall intensity of drug effects, were responsible for smoking cessation. Nine of 15 participants (60%) met criteria for "complete" mystical experience. Smoking cessation outcomes were significantly correlated with measures of mystical experience on session days, as well as retrospective ratings of personal meaning and spiritual significance of psilocybin sessions. These results suggest a mediating role of mystical experience in psychedelic-facilitated addiction treatment.

Cocaine dependent individuals discount future rewards more than future losses for both cocaine and monetary outcomes

Cocaine dependence and other forms of drug dependence are associated with steeper devaluation of future outcomes (delay discounting). Although studies in this domain have typically assessed choices between monetary gains (e.g., receive less money now versus receive more money after a delay), delay discounting is also applicable to decisions involving losses (e.g., small loss now versus larger delayed loss), with gains typically discounted more than losses (the "sign effect"). It is also known that drugs are discounted more than equivalently valued money. In the context of drug dependence, however, relatively little is known about the discounting of delayed monetary and drug losses and the presence of the sign effect. In this within-subject, laboratory study, delay discounting for gains and losses was assessed for cocaine and money outcomes in cocaine-dependent individuals (n=89). Both cocaine and monetary gains were discounted at significantly greater rates than cocaine and monetary losses, respectively (i.e., the sign effect). Cocaine gains were discounted significantly more than monetary gains, but cocaine and monetary losses were discounted similarly. Results suggest that cocaine is discounted by cocaine-dependent individuals in a systematic manner similar to other rewards. Because the sign effect was shown for both cocaine and money, delayed aversive outcomes may generally have greater impact than delayed rewards in shaping present behavior in this population.

Can psychedelic compounds play a part in drug dependence therapy?

After a 40-year hiatus there is now a revisiting of psychedelic drug therapy throughout psychiatry, with studies examining the drugs psilocybin, ketamine, ibogaine and ayahuasca in the treatment of drug dependence. Limitations to these therapies are both clinical and legal, but the possibility of improving outcomes for patients with substance dependency imposes an obligation to research this area.

The behavioral economics of substance use disorders: reinforcement pathologies and their repair

The field of behavioral economics has made important inroads into the understanding of substance use disorders through the concept of reinforcer pathology. Reinforcer pathology refers to the joint effects of (a) the persistently high valuation of a reinforcer, broadly defined to include tangible commodities and experiences, and/or (b) the excessive preference for the immediate acquisition or consumption of a commodity despite long-term negative outcomes. From this perspective, reinforcer pathology results from the recursive interactions of endogenous person-level variables and exogenous environment-level factors. The current review describes the basic principles of behavioral economics that are central to reinforcer pathology, the processes that engender reinforcer pathology, and the approaches and procedures that can repair reinforcement pathologies. The overall goal of this review is to present a new understanding of substance use disorders as viewed by recent advances in behavioral economics.

Opportunity costs of reward delays and the discounting of hypothetical money and cigarettes

Humans are reported to discount delayed rewards at lower rates than nonhumans. However, nonhumans are studied in tasks that restrict reinforcement during delays, whereas humans are typically studied in tasks that do not restrict reinforcement during delays. In nonhuman tasks, the opportunity cost of restricted reinforcement during delays may increase delay discounting rates. The present within-subjects study used online crowdsourcing (Amazon Mechanical Turk, or MTurk) to assess the discounting of hypothetical delayed money (and cigarettes in smokers) under four hypothetical framing conditions differing in the availability of reinforcement during delays. At one extreme, participants were free to leave their computer without returning, and engage in any behavior during reward delays (modeling typical human tasks). At the opposite extreme, participants were required to stay at their computer and engage in little other behavior during reward delays (modeling typical nonhuman tasks). Discounting rates increased as an orderly function of opportunity cost. Results also indicated predominantly hyperbolic discounting, the "magnitude effect," steeper discounting of cigarettes than money, and positive correlations between discounting rates of these commodities. This is the first study to test the effects of opportunity costs on discounting, and suggests that procedural differences may partially account for observed species differences in discounting.

Pilot study of the 5-HT2AR agonist psilocybin in the treatment of tobacco addiction

Despite suggestive early findings on the therapeutic use of hallucinogens in the treatment of substance use disorders, rigorous follow-up has not been conducted. To determine the safety and feasibility of psilocybin as an adjunct to tobacco smoking cessation treatment we conducted an open-label pilot study administering moderate (20 mg/70 kg) and high (30 mg/70 kg) doses of psilocybin within a structured 15-week smoking cessation treatment protocol. Participants were 15 psychiatrically healthy nicotine-dependent smokers (10 males; mean age of 51 years), with a mean of six previous lifetime quit attempts, and smoking a mean of 19 cigarettes per day for a mean of 31 years at intake. Biomarkers assessing smoking status, and self-report measures of smoking behavior demonstrated that 12 of 15 participants (80%) showed seven-day point prevalence abstinence at 6-month follow-up. The observed smoking cessation rate substantially exceeds rates commonly reported for other behavioral and/or pharmacological therapies (typically <35%). Although the open-label design does not allow for definitive conclusions regarding the efficacy of psilocybin, these findings suggest psilocybin may be a potentially efficacious adjunct to current smoking cessation treatment models. The present study illustrates a framework for future research on the efficacy and mechanisms of hallucinogen-facilitated treatment of addiction.

Examining delay discounting of condom-protected sex among opioid-dependent women and non-drug-using control women

BACKGROUND

Opioid-dependent (OD) women tend to engage in unprotected sex with high-risk partners, placing themselves at elevated risk for sexually transmitted HIV infection. This behavior generally persists after completion of interventions that increase sexual HIV risk reduction knowledge and skills, suggesting that decision-making biases may influence HIV transmission among OD women.

METHODS

The primary aim of this report is to examine delay discounting of condom-protected sex among OD women and non-drug-using control women using the novel Sexual Discounting Task (SDT; Johnson and Bruner, 2012). Data were collected from 27 OD women and 33 non-drug-using control women using the SDT, a monetary discounting task, and the Barratt impulsiveness scale (BIS-11).

RESULTS

OD women discounted the value of delayed condom-protected sex more steeply than controls for hypothetical sexual partners in the two sets of paired partner conditions examined. Overall, women discounted condom protected sex more steeply for partners they perceived as being lowest STI risk vs. those they perceived as being highest risk. Steeper discounting of condom-protected sex was significantly associated with higher scores on the BIS-11, but not with discounting of money.

CONCLUSIONS

Delay discounting of condom-protected sex differs between OD women and non-drug-using women, is sensitive to perceived partner risk, and is correlated with a self-report measure of impulsivity, the BIS-11. The effect of delay on sexual decision-making is a critical but underappreciated dimension of HIV risk among women, and the SDT appears to be a promising measure of this domain. Further investigation of these relationships is warranted.

Demand curves for hypothetical cocaine in cocaine-dependent individuals

RATIONALE

Drug purchasing tasks have been successfully used to examine demand for hypothetical consumption of abused drugs including heroin, nicotine, and alcohol. In these tasks, drug users make hypothetical choices whether to buy drugs, and if so, at what quantity, at various potential prices. These tasks allow for behavioral economic assessment of that drug's intensity of demand (preferred level of consumption at extremely low prices) and demand elasticity (sensitivity of consumption to price), among other metrics. However, a purchasing task for cocaine in cocaine-dependent individuals has not been investigated.

OBJECTIVES

This study examined a novel Cocaine Purchasing Task and the relation between resulting demand metrics and self-reported cocaine use data.

METHODS

Participants completed a questionnaire assessing hypothetical purchases of cocaine units at prices ranging from $0.01 to $1,000. Demand curves were generated from responses on the Cocaine Purchasing Task. Correlations compared metrics from the demand curve to measures of real-world cocaine use.

RESULTS

Group and individual data were well modeled by a demand curve function. The validity of the Cocaine Purchasing Task was supported by a significant correlation between the demand curve metrics of demand intensity and O max (determined from Cocaine Purchasing Task data) and self-reported measures of cocaine use. Partial correlations revealed that after controlling for demand intensity, demand elasticity and the related measure, P max, were significantly correlated with real-world cocaine use.

CONCLUSIONS

Results indicate that the Cocaine Purchasing Task produces orderly demand curve data, and that these data relate to real-world measures of cocaine use.

Hallucinogen use predicts reduced recidivism among substance-involved offenders under community corrections supervision

Hallucinogen-based interventions may benefit substance use populations, but contemporary data informing the impact of hallucinogens on addictive behavior are scarce. Given that many individuals in the criminal justice system engage in problematic patterns of substance use, hallucinogen treatments also may benefit criminal justice populations. However, the relationship between hallucinogen use and criminal recidivism is unknown. In this longitudinal study, we examined the relationship between naturalistic hallucinogen use and recidivism among individuals under community corrections supervision with a history of substance involvement (n=25,622). We found that hallucinogen use predicted a reduced likelihood of supervision failure (e.g. noncompliance with legal requirements including alcohol and other drug use) while controlling for an array of potential confounding factors (odds ratio (OR)=0.60 (0.46, 0.79)). Our results suggest that hallucinogens may promote alcohol and other drug abstinence and prosocial behavior in a population with high rates of recidivism.

Test-retest reliability and gender differences in the sexual discounting task among cocaine-dependent individuals

The Sexual Discounting Task uses the delay discounting framework to examine sexual HIV risk behavior. Previous research showed task performance to be significantly correlated with self-reported HIV risk behavior in cocaine dependence. Test-retest reliability and gender differences had remained unexamined. The present study examined the test-retest reliability of the Sexual Discounting Task. Cocaine-dependent individuals (18 men, 13 women) completed the task in two laboratory visits ∼7 days apart. Participants selected photographs of individuals with whom they were willing to have casual sex. Among these, participants identified the individual most (and least) likely to have a sexually transmitted infection (STI), and the individual with whom he or she most (and least) wanted to have sex. In reference to these individuals, participants rated their likelihood of having unprotected sex versus waiting to have sex with a condom, at various delays. A money delay discounting task was also completed at the first visit. Significant differences in discounting among partner conditions were shown. Differential stability was demonstrated by significant, positive correlations between test and retest for all four partner conditions. Absolute stability was demonstrated by statistical equivalence tests between test and retest, and also supported by a lack of significant differences between test and retest. Men generally discounted significantly more than women for sexual outcomes but not money. Results suggest the Sexual Discounting Task to be a reliable measure in cocaine-dependent individuals, which supports its use as a repeated measure in clinical research, for example, studies examining acute drug effects on sexual risk and the effects of addiction treatment and HIV prevention interventions on sexual risk.

Novel Drugs of Abuse: A Snapshot of an Evolving Marketplace

BACKGROUND & OBJECTIVES

Over the past decade, non-medical use of novel drugs has proliferated worldwide. In most cases these are synthetic drugs first synthesized in academic or pharmaceutical laboratories for research or drug development purposes, but also include naturally occurring substances that do not fit the typical pharmacological or behavioral profile of traditional illicit substances. Perhaps most unique to this generation of new drugs is that they are being sold over the counter and on the Internet as "legal highs" or substitutes for traditional illicit drugs such as cannabis, cocaine, amphetamines, MDMA, and LSD. The purpose of this review is to provide an overview of novel drugs in current use, including the epidemiology of use and toxicologic and pharmacological properties, and to offer some guidelines to clinicians who see patients experiencing adverse effects from these drugs.

METHOD

We review the known scientific literature on recently introduced synthetic drug types, synthetic cannabinoids and synthetic cathinones, and the hallucinogen Salvia divinorum.

RESULTS

These substances comprise part of a rapidly evolving and controversial drug market that has challenged definitions of what is legal and illegal, has benefitted from open commercial sales without regulatory oversight, and is noteworthy for the pace at which new substances are introduced.

CONCLUSIONS

This emerging trend in substance use presents significant and unique public health and criminal justice challenges. At this time, these substances are not detected in routine drug screens and substance-specific treatment for cases of use-related toxicity are not available. Clinicians are encouraged to learn characteristic signs associated with misuse of novel drugs to recognize cases in their practice, and are recommended to use a symptom-specific approach for treatment in each case.

Comparative abuse liability of GHB and ethanol in humans

Gamma-hydroxybutyric acid (GHB; sodium oxybate) is approved for narcolepsy symptom treatment, and it is also abused. This study compared the participant-rated, observer-rated effects, motor/cognitive, physiological, and reinforcing effects of GHB and ethanol in participants with histories of sedative (including alcohol) abuse. Fourteen participants lived on a residential unit for ∼1 month. Sessions were conducted Monday through Friday. Measures were taken before and repeatedly up to 24 hours after drug administration. Participants were administered GHB (1, 2, 4, 6, 8, and 10 g/70 kg), ethanol (12, 24, 48, 72, 96, and 120 g/70 kg), or placebo in a double-blind, within-subjects design. For safety, GHB and ethanol were administered in an ascending dose sequence, with placebos and both drugs intermixed across sessions. The sequence for each drug was stopped if significant impairment or intolerable effects occurred. Only 9 and 10 participants received the full dose range for GHB and ethanol, respectively. The highest doses of GHB and ethanol showed onset within 30 minutes, with peak effects at 60 minutes. GHB effects dissipated between 4 and 6 hours, whereas ethanol effects dissipated between 6 and 8 hours. Dose-related effects were observed for both drugs on a variety of measures assessing sedative drug effects, abuse liability, performance impairment, and physiological effects. Within-session measures of abuse liability were similar between the two drugs. However, postsession measures of abuse liability, including a direct preference test between the highest tolerated doses of each drug, suggested somewhat greater abuse liability for GHB, most likely as a result of the delayed aversive ethanol effects (e.g., headache).

Acute cognitive effects of high doses of dextromethorphan relative to triazolam in humans

BACKGROUND

Although concerns surrounding high-dose dextromethorphan (DXM) abuse have recently increased, few studies have examined the acute cognitive effects of high doses of DXM. The aim of this study was to compare the cognitive effects of DXM with those of triazolam and placebo.

METHODS

Single, acute, oral doses of DXM (100, 200, 300, 400, 500, 600, 700, 800 mg/70 kg), triazolam (0.25, 0.5mg/70 kg), and placebo were administered p.o. to twelve healthy volunteers with histories of hallucinogen use, under double-blind conditions, using an ascending dose run-up design. Effects on cognitive performance were examined at baseline and after drug administration for up to 6h.

RESULTS

Both triazolam and DXM produced acute impairments in attention, working memory, episodic memory, and metacognition. Impairments observed following doses of 100-300 mg/70 kg DXM were generally smaller in magnitude than those observed after 0.5mg/70 kg triazolam. Doses of DXM that impaired performance to the same extent as triazolam were in excess of 10-30 times the therapeutic dose of DXM.

CONCLUSION

The magnitude of the doses required for these effects and the absence of effects on some tasks within the 100-300 mg/70 kg dose range of DXM, speak to the relatively broad therapeutic window of over-the-counter DXM preparations when used appropriately. However, the administration of supratherapeutic doses of DXM resulted in acute cognitive impairments on all tasks that were examined. These findings are likely relevant to cases of high-dose DXM abuse.

Effects of varenicline on abstinence and smoking reward following a programmed lapse

INTRODUCTION

Varenicline (Chantix®) is an efficacious first-line medication for smoking cessation. Studies suggest that one mechanism by which varenicline facilitates sustained smoking abstinence is by reducing the likelihood of relapse to smoking when a lapse, or slip, occurs during a quit attempt. The present study extends this line of research by conducting a prospective laboratory study to examine the relapse prevention effects of varenicline following a programmed lapse.

METHODS

Daily smokers (N = 47) completed a 5-week outpatient study in which they were randomized to receive varenicline or placebo. The first week was a medication induction period that was immediately followed by a 4-week quit attempt. A programmed lapse (2 cigarettes smoked in the laboratory) occurred on the second day of the quit attempt.

RESULTS

Participants receiving varenicline were slower to relapse and had greater total abstinence rates following lapse exposure. Participants in the varenicline group rated lapse cigarettes lower on measures of reward and intoxication and showed increased behavioral economic demand elasticity for cigarettes (reduced cigarette purchasing at higher prices) compared with those receiving placebo.

CONCLUSIONS

These results demonstrate a relapse prevention effect of varenicline following smoking lapse exposure and suggest that an attenuation of reward from smoking and the blunting of subjective effects of smoking may underlie and/or contribute to this effect.

Factor Analysis of the Mystical Experience Questionnaire: A Study of Experiences Occasioned by the Hallucinogen Psilocybin

A large body of historical evidence describes the use of hallucinogenic compounds, such as psilocybin mushrooms, for religious purposes. But few scientific studies have attempted to measure or characterize hallucinogen-occasioned spiritual experiences. The present study examined the factor structure of the Mystical Experience Questionnaire (MEQ), a self-report measure that has been used to assess the effects of hallucinogens in laboratory studies. Participants (N=1602) completed the 43-item MEQ in reference to a mystical or profound experience they had had after ingesting psilocybin. Exploratory factor analysis of the MEQ retained 30 items and revealed a 4-factor structure covering the dimensions of classic mystical experience: unity, noetic quality, sacredness (F1); positive mood (F2); transcendence of time/space (F3); and ineffability (F4). MEQ factor scores showed good internal reliability and correlated with the Hood Mysticism Scale, indicating convergent validity. Participants who endorsed having had a mystical experience on psilocybin, compared to those who did not, had significantly higher factor scores, indicating construct validity. The 4-factor structure was confirmed in a second sample (N=440) and demonstrated superior fit compared to alternative models. The results provide initial evidence of the validity, reliability, and factor structure of a 30-item scale for measuring single, hallucinogen-occasioned mystical experiences, which may be a useful tool in the scientific study of mysticism.

High doses of dextromethorphan, an NMDA antagonist, produce effects similar to classic hallucinogens

RATIONALE

Although reports of dextromethorphan (DXM) abuse have increased recently, few studies have examined the effects of high doses of DXM.

OBJECTIVE

This study in humans evaluated the effects of supratherapeutic doses of DXM and triazolam.

METHODS

Single, acute oral doses of DXM (100, 200, 300, 400, 500, 600, 700, and 800 mg/70 kg), triazolam (0.25 and 0.5 mg/70 kg), and placebo were administered to 12 healthy volunteers with histories of hallucinogen use, under double-blind conditions, using an ascending dose run-up design. Subjective, behavioral, and physiological effects were assessed repeatedly after drug administration for 6 h.

RESULTS

Triazolam produced dose-related increases in subject-rated sedation, observer-rated sedation, and behavioral impairment. DXM produced a profile of dose-related physiological and subjective effects differing from triazolam. DXM effects included increases in blood pressure, heart rate, and emesis; increases in observer-rated effects typical of classic hallucinogens (e.g., distance from reality, visual effects with eyes open and closed, joy, anxiety); and participant ratings of stimulation (e.g., jittery, nervous), somatic effects (e.g., tingling, headache), perceptual changes, end-of-session drug liking, and mystical-type experience. After 400 mg/70 kg DXM, 11 of 12 participants indicated on a pharmacological class questionnaire that they thought they had received a classic hallucinogen (e.g., psilocybin). Drug effects resolved without significant adverse effects by the end of the session. In a 1-month follow-up, volunteers attributed increased spirituality and positive changes in attitudes, moods, and behavior to the session experiences.

CONCLUSIONS

High doses of DXM produced effects distinct from triazolam and had characteristics that were similar to the classic hallucinogen psilocybin.

An efficient operant choice procedure for assessing delay discounting in humans: initial validation in cocaine-dependent and control individuals

Delay discounting is the decline in a consequence's control of behavior as a function of its delay, and may be a fundamental behavioral process in drug dependence. Human delay-discounting studies have usually relied on choices between hypothetical rewards. Some human tasks have assessed delay discounting using operant procedures with consequences provided during the task, as in nonhuman animal studies. However, these tasks have limitations such as long duration, potentially indeterminate data, or confounding the effect of delay with probability. A study in 20 cocaine-dependent volunteers and 20 demographically matched non-cocaine-dependent volunteers was designed to investigate a novel operant delay-discounting task providing monetary reinforcement by coin delivery throughout the task (Quick Discounting Operant Task; QDOT). Participants completed a hypothetical delay-discounting procedure, a potentially real reward delay-discounting procedure, and an existing operant delay-discounting task: the Experiential Discounting Task (EDT). The QDOT resulted in complete data for all participants, showed systematic effects of delay that were well described by a hyperbolic function, had a maximum duration of 17 min, and resulted in relatively little variability in session earnings. QDOT performance was significantly, positively correlated with performance on the EDT but not the other tasks. The QDOT resulted in an effect size between the groups that was similar to most other delay-discounting tasks examined, and showed that the cocaine-dependent participants delay discounted significantly more than the control participants. The QDOT is an efficient operant human delay-discounting task that may be useful in a variety of experimental settings.

Psilocybin dose-dependently causes delayed, transient headaches in healthy volunteers

BACKGROUND

Psilocybin is a well-characterized classic hallucinogen (psychedelic) with a long history of religious use by indigenous cultures, and nonmedical use in modern societies. Although psilocybin is structurally related to migraine medications, and case studies suggest that psilocybin may be efficacious in treatment of cluster headache, little is known about the relationship between psilocybin and headache.

METHODS

This double-blind study examined a broad range of psilocybin doses (0, 5, 10, 20, and 30 mg/70 kg) on headache in 18 healthy participants.

RESULTS

Psilocybin frequently caused headache, the incidence, duration, and severity of which increased in a dose-dependent manner. All headaches had delayed onset, were transient, and lasted no more than a day after psilocybin administration.

CONCLUSIONS

Possible mechanisms for these observations are discussed, and include induction of delayed headache through nitric oxide release. These data suggest that headache is an adverse event to be expected with the nonmedical use of psilocybin-containing mushrooms as well as the administration of psilocybin in human research. Headaches were neither severe nor disabling, and should not present a barrier to future psilocybin research.

The Sexual Discounting Task: HIV risk behavior and the discounting of delayed sexual rewards in cocaine dependence

BACKGROUND

Cocaine dependence is associated with high rates of sexual risk behavior and HIV infection. However, little is known about the responsible mechanism(s).

METHODS

Cocaine-dependent individuals (N=62) completed a novel Sexual Discounting Task assessing decisions between immediate unprotected sex and delayed sex with a condom across four hypothetical partners: most (and least) likely to have a sexually transmitted infection (STI), and most (and least) sexually desirable; a real rewards money delay-discounting task, and self-reported sexual risk behavior using the HIV Risk-Taking Behavior Scale (HRBS).

RESULTS

Sexual Discounting Task results were largely systematic and showed a strong effect of delay in decreasing condom use. Sexual discounting (preference for immediate unprotected sex) was significantly greater when making responses for partners judged least (compared to most) likely to have an STI, and for partners judged most (compared to least) desirable. Differences in sexual discounting were significant after controlling for differences in condom use (with no delay) between conditions. Greater discounting in 3 of the 4 Sexual Discounting Task conditions, but not in the money discounting task, was associated with greater self-reported sexual risk behavior as measured by the HRBS.

CONCLUSIONS

Results suggest that delay is a critical variable strongly affecting HIV sexual risk behavior, and that the Sexual Discounting Task provides a clinically sensitive measure of this phenomenon that may address a variety of questions about HIV risk in future research. The wealth of behavioral and neurobiological data on delay discounting should be brought to bear on HIV education and prevention.

Celiac disease: Management of persistent symptoms in patients on a gluten-free diet

AIM: To investigate all patients referred to our center with non-responsive celiac disease (NRCD), to establish a cause for their continued symptoms.

METHODS: We assessed all patients referred to our center with non-responsive celiac disease over an 18-mo period. These individuals were investigated to establish the eitiology of their continued symptoms. The patients were first seen in clinic where a thorough history and examination were performed with routine blood work including tissue transglutaminase antibody measurement. They were also referred to a specialist gastroenterology dietician to try to identift any lapses in the diet and sources of hidden gluten ingestion. A repeat small intestinal biopsy was also performed and compared to biopsies from the referring hospital where possible. Colonoscopy, lactulose hydrogen breath testing, pancreolauryl testing and computed tomography scan of the abdomen were undertaken if the symptoms persisted. Their clinical progress was followed over a minimum of 2 years.

RESULTS: One hundred and twelve consecutive patients were referred with NRCD. Twelve were found not to have celiac disease (CD). Of the remaining 100 patients, 45% were not adequately adhering to a strict gluten-free diet, with 24 (53%) found to be inadvertently ingesting gluten, and 21 (47%) admitting non-compliance. Microscopic colitis was diagnosed in 12% and small bowel bacterial overgrowth in 9%. Refractory CD was diagnosed in 9%. Three of these were diagnosed with intestinal lymphoma. After 2 years, 78 patients remained well, eight had continuing symptoms, and four had died.

CONCLUSION: In individuals with NRCD, a remediable cause can be found in 90%: with continued gluten ingestion as the leading cause. We propose an algorithm for investigation.

Traction-induced foveal damage predisposes eyes with pre-existing posterior vitreous detachment to idiopathic macular hole formation

AIM

To propose a new mechanism for the development of idiopathic macular hole in the setting of pre-existing posterior vitreous detachment (PVD).

METHODS

Patients were examined clinically with fundus contact lens biomicroscopy and high-definition optical coherence tomography (OCT) was used to characterize the structural changes in the fovea following PVD.

RESULTS

Two patients presented with vitreofoveal separation and were found by high-definition OCT to have subtle foveal disruption and irregularity of the foveal contour with no evidence of a full thickness macular hole. Sequential examination of these patients demonstrated delayed formation of idiopathic macular hole.

CONCLUSION

Traction-induced inner foveal damage occurring before or coincident with spontaneous vitreofoveal separation destabilizes the fovea and predisposes some eyes to delayed macular hole formation.

Psilocybin occasioned mystical-type experiences: immediate and persisting dose-related effects

RATIONALE

This dose-effect study extends previous observations showing that psilocybin can occasion mystical-type experiences having persisting positive effects on attitudes, mood, and behavior.

OBJECTIVES

This double-blind study evaluated psilocybin (0, 5, 10, 20, 30 mg/70 kg, p.o.) administered under supportive conditions.

METHODS

Participants were 18 adults (17 hallucinogen-naïve). Five 8-h sessions were conducted individually for each participant at 1-month intervals. Participants were randomized to receive the four active doses in either ascending or descending order (nine participants each). Placebo was scheduled quasi-randomly. During sessions, volunteers used eyeshades and were instructed to direct their attention inward. Volunteers completed questionnaires assessing effects immediately after and 1 month after each session, and at 14 months follow-up.

RESULTS

Psilocybin produced acute perceptual and subjective effects including, at 20 and/or 30 mg/70 kg, extreme anxiety/fear (39% of volunteers) and/or mystical-type experience (72% of volunteers). One month after sessions at the two highest doses, volunteers rated the psilocybin experience as having substantial personal and spiritual significance, and attributed to the experience sustained positive changes in attitudes, mood, and behavior, with the ascending dose sequence showing greater positive effects. At 14 months, ratings were undiminished and were consistent with changes rated by community observers. Both the acute and persisting effects of psilocybin were generally a monotonically increasing function of dose, with the lowest dose showing significant effects.

CONCLUSIONS

Under supportive conditions, 20 and 30 mg/70 kg psilocybin occasioned mystical-type experiences having persisting positive effects on attitudes, mood, and behavior. Implications for therapeutic trials are discussed.

Mystical experiences occasioned by the hallucinogen psilocybin lead to increases in the personality domain of openness

A large body of evidence, including longitudinal analyses of personality change, suggests that core personality traits are predominantly stable after age 30. To our knowledge, no study has demonstrated changes in personality in healthy adults after an experimentally manipulated discrete event. Intriguingly, double-blind controlled studies have shown that the classic hallucinogen psilocybin occasions personally and spiritually significant mystical experiences that predict long-term changes in behaviors, attitudes and values. In the present report we assessed the effect of psilocybin on changes in the five broad domains of personality - Neuroticism, Extroversion, Openness, Agreeableness, and Conscientiousness. Consistent with participant claims of hallucinogen-occasioned increases in aesthetic appreciation, imagination, and creativity, we found significant increases in Openness following a high-dose psilocybin session. In participants who had mystical experiences during their psilocybin session, Openness remained significantly higher than baseline more than 1 year after the session. The findings suggest a specific role for psilocybin and mystical-type experiences in adult personality change.

Human psychopharmacology and dose-effects of salvinorin A, a kappa opioid agonist hallucinogen present in the plant Salvia divinorum

Salvinorin A is a potent, selective nonnitrogenous kappa opioid agonist and the known psychoactive constituent of Salvia divinorum, a member of the mint family that has been used for centuries by Mazatec shamans of Mexico for divination and spiritual healing. S. divinorum has over the last several years gained increased popularity as a recreational drug. This is a double-blind, placebo controlled study of salvinorin A in 4 psychologically and physically healthy hallucinogen-using adults. Across sessions, participants inhaled 16 ascending doses of salvinorin A and 4 intermixed placebo doses under comfortable and supportive conditions. Doses ranged from 0.375 μg/kg to 21 μg/kg. Subject-rated drug strength was assessed every 2 min for 60 min after inhalation. Orderly time- and dose-related effects were observed. Drug strength ratings peaked at 2 min (first time point) and definite subjective effects were no longer present at approximately 20 min after inhalation. Dose-related increases were observed on questionnaire measures of mystical-type experience (Mysticism Scale) and subjective effects associated with classic serotonergic (5-HT2(A)) hallucinogens (Hallucinogen Rating Scale). Salvinorin A did not significantly increase heart rate or blood pressure. Participant narratives indicated intense experiences characterized by disruptions in vestibular and interoceptive signals (e.g., change in spatial orientation, pressure on the body) and unusual and sometimes recurring themes across sessions such as revisiting childhood memories, cartoon-like imagery, and contact with entities. Under these prepared and supportive conditions, salvinorin A occasioned a unique profile of subjective effects having similarities to classic hallucinogens, including mystical-type effects.

Effects of oral caffeine pretreatment on response to intravenous nicotine and cocaine

Previous research suggests that under conditions of chronic daily caffeine administration, caffeine increases the effects of nicotine. Little is known about the effects of caffeine pretreatment on response to nicotine under infrequent caffeine administration conditions. The present study examined whether infrequent (not on consecutive days) acute oral caffeine administration alters subject-rated, physiological, and monetary value effects of intravenous nicotine in regular users of caffeine, tobacco, and cocaine. To determine the specificity of effects of caffeine on response to nicotine, the effects of caffeine administration on response to intravenous cocaine (another short-acting stimulant) were also studied. Fourteen (1 woman) volunteers participated in this 3-4 week, double-blind, inpatient study. Volunteers participated in 10 experimental conditions in pseudo-randomized order, in which oral caffeine (250 mg/70 kg) or placebo was administered 1 hr before an intravenous injection, consisting of nicotine (1 or 2 mg/70 kg), cocaine (15 or 30 mg/70 kg), or saline. Infrequent acute caffeine pretreatment attenuated the increase resulting from 2 mg/70 kg nicotine administration on ratings of "rush," "good effects," "liking," "high," and "drowsy/sleepy." Caffeine had no significant effect on physiological response to nicotine. Caffeine had no significant effect on subject-rated and physiological response to cocaine, with the exception that caffeine significantly augmented blood pressure response to cocaine. In contrast to the previous research using chronic caffeine maintenance, these data suggest that infrequent acute caffeine administration may attenuate nicotine effects.

Fulminant Wilson's disease requiring liver transplantation in one monozygotic twin despite identical genetic mutation

Acute decompensated Wilson's disease (WD) that presents as fulminant hepatic failure carries significant mortality without hepatic replacement. The abnormal gene implicated in WD, ATP7B, has been mapped to chromosome 13, and leads to decreased passage of copper from hepatocytes to bile. Excess copper accumulation exceeds hepatocyte storage capacity resulting in intracellular necrosis, apoptosis and cell death in various organs of the body. The hepatic injury induced by the abnormal accumulation of copper in WD has variable presentation such as acute hepatitis, rapid hepatic deterioration resembling fulminant hepatic failure, or as progressive chronic liver disease in the form of chronic active hepatitis or cirrhosis. There are reports in the literature describing monozygotic (identical) twins with similar hepatic progression requiring liver transplantation, however, with different neurological outcome after transplant. We report a case of one monozygotic twin presenting with acute liver failure requiring emergent liver transplantation while the other twin presented with mild liver disease, when both shared an identical genetic mutation.

Transforming growth factor-β stimulates the expression of eotaxin/CC chemokine ligand 11 and its promoter activity through binding site for nuclear factor-κβ in airway smooth muscle cells

BACKGROUND

Chemokines ligands of CCR3 including eotaxin/CC chemokine ligand 11 (CCL11) may contribute to the pathogenesis of asthma. These chemokines and a growth factor (TGF-beta) may be involved in the process of airway remodelling.

OBJECTIVE

We analysed the effects of TGF-beta on the expression of CCR3 ligands in human airway smooth muscle (HASM) cells and investigated the mechanisms.

METHODS

HASM cells were cultured and treated with TGF-beta and Th2 cytokines IL-4 or IL-13. Expression of mRNA was analysed by real-time PCR. Secretion of CCL11 into the culture medium was analysed by ELISA. Transcriptional regulation of CCL11 was analysed by luciferase assay using CCL11 promoter-luciferase reporter plasmids.

RESULTS

IL-4 or IL-13 significantly up-regulated the expression of mRNAs for CCL11 and CCL26. TGF-beta alone did not increase the expression of chemokine mRNAs, but enhanced the induction of only CCL11 by IL-4 or IL-13 among CCR3 ligands. Activity of the CCL11 promoter was stimulated by IL-4, and this activity was enhanced by TGF-beta. Activation by IL-4 or IL-4 plus TGF-beta was lost by mutation of the binding site for signal transducers and activators of transcription-6 (STAT6) in the promoter. Cooperative activation by IL-4 and TGF-beta was inhibited by mutation of the binding site for nuclear factor-kappaB (NF-kappaB) in the promoter. Pretreatment with an inhibitor of NF-kappaB and glucocorticoid fluticasone propionate significantly inhibited the expression of CCL11 mRNA induced by IL-4 plus TGF-beta, indicating the importance of NF-kappaB in the cooperative activation of CCL11 transcription by TGF-beta and IL-4.

CONCLUSION

These results indicate that Th2 cytokines and TGF-beta may contribute to the pathogenesis of asthma by stimulating expression of CCL11. The transcription factors STAT6 and NF-kappaB may play pivotal roles in this process.

Delay discounting in current and former marijuana-dependent individuals

Studies have found that a variety of drug-dependent groups discount delayed rewards more than matched controls. This study compared delay discounting for a hypothetical $1,000 reward among dependent marijuana users, former dependent marijuana users, and matched controls. Discounting of marijuana was also assessed in the currently marijuana-dependent group. No significant differences in discounting were detected among the groups; however, currently dependent users showed a trend to discount money more than the other 2 groups. Within the dependent marijuana group, marijuana was discounted more than money, and discounting for money and marijuana was significantly and positively correlated. Regression analyses indicated that delay discounting was more closely associated with tobacco use than marijuana use. A variety of questionnaires were also administered, including impulsivity questionnaires. Dependent marijuana users scored as significantly more impulsive on the Impulsiveness subscale of the Eysenck Impulsiveness-Venturesomeness-Empathy questionnaire than controls. However, the 3 groups did not significantly differ on several other personality questionnaires, including the Barratt Impulsivity Scale-11. The Stanford Time Perception Inventory Present-Fatalistic subscale was positively correlated with money and marijuana discounting, indicating that a greater sense of powerlessness over the future is related to greater delay discounting. Results suggest that current marijuana dependence may be associated with a trend toward increased delay discounting, but this effect size appears to be smaller for marijuana than for previously examined drugs.

Osteoporosis in patients over 50 years of age following restorative proctocolectomy for ulcerative colitis: is DXA screening warranted?

BACKGROUND

Ulcerative colitis (UC) and increasing age are associated with an increased risk of osteoporosis. Screening of postmenopausal women and men older than 50 years with ulcerative colitis for osteoporosis is recommended. The prevalence of osteoporosis in restorative proctocolectomy (RPC) patients more than 50 years old is not known.

METHODS

Fifty-three consecutive patients older than age 50 who had undergone RPC for UC underwent a bone density scan (DXA). Sex, smoking status, age at diagnosis of UC, duration of UC, age at RPC, years since RPC, age at DXA, and pouch histological inflammatory score were recorded. The Kruskal-Wallis test and Spearman's correlation coefficient were used to analyze the data.

RESULTS

Fifty-three patients were studied; their median age was 58 years, and the median age at RPC was 45. The prevalence of osteopenia and osteoporosis was 43.4% and 13.2%, respectively. Age at RPC was negatively correlated with bone density (P = 0.041, r = 0.281), and there was a negative correlation approaching significance with age at the time of DXA (P = 0.071, r = -0.250). No other factor studied correlated with bone density.

CONCLUSIONS

The prevalence of osteoporosis and osteopenia found in this study is similar to that reported for UC patients who have not undergone RPC. Patients having RPC should be screened in line with current UC guidelines, targeting those older than 50 years.

Response disinhibition evoked by the administration of nicotine and nicotine-associated contextual cues

Nicotine causes dose-dependent alterations in accuracy on the differential-reinforcement of low-rate responding (DRL) 29.5-s schedule in rats. The current investigation evaluated whether nicotine-associated contextual cues can produce nicotine-like perturbations in DRL-schedule performance in the absence of nicotine. Nicotine and saline administrations occurred just prior to DRL 29.5-s schedule responding for sucrose solution, and two different experimental contexts (differentiated by visual, olfactory, and tactile cues) were utilized. All subjects (N=16) experienced two consecutive sessions of DRL-schedule responding per day. The experimental group (n=8) was exposed to saline immediately prior to the first session and 0.3mg/kg nicotine before the second session, and the context was changed between sessions. This sequence of saline and then nicotine administration, paired with two reliable contexts, persisted for 12 consecutive days and successive nicotine administrations corresponded with increasingly poorer performance on the DRL 29.5-s schedule. No nicotine was administered for days 13-20 during context testing, and the nicotine-associated context produced response disinhibition on the DRL schedule. Two control groups were included in the design; subjects in one control group (n=4) received saline in each context to verify that the contexts themselves were not exerting control over operant responding. To assess how explicit and non-explicit pairings of nicotine and contextual cues influenced DRL behavior, subjects in a second control group (n=4) were given nicotine prior to the second session, but the contexts were not altered between sessions. The results from this experiment suggest that environmental stimuli associated with nicotine exposure can come to elicit nicotine-induced performance decrements on a DRL 29.5-s schedule.

Probing noise in flux qubits via macroscopic resonant tunneling

Macroscopic resonant tunneling between the two lowest lying states of a bistable rf SQUID is used to characterize noise in a flux qubit. Measurements of the incoherent decay rate as a function of flux bias revealed a Gaussian-shaped profile that is not peaked at the resonance point but is shifted to a bias at which the initial well is higher than the target well. The rms amplitude of the noise, which is proportional to the dephasing rate 1/tauphi, was observed to be weakly dependent on temperature below 70 mK. Analysis of these results indicates that the dominant source of low energy flux noise in this device is a quantum mechanical environment in thermal equilibrium.

Human hallucinogen research: guidelines for safety

There has recently been a renewal of human research with classical hallucinogens (psychedelics). This paper first briefly discusses the unique history of human hallucinogen research, and then reviews the risks of hallucinogen administration and safeguards for minimizing these risks. Although hallucinogens are relatively safe physiologically and are not considered drugs of dependence, their administration involves unique psychological risks. The most likely risk is overwhelming distress during drug action ('bad trip'), which could lead to potentially dangerous behaviour such as leaving the study site. Less common are prolonged psychoses triggered by hallucinogens. Safeguards against these risks include the exclusion of volunteers with personal or family history of psychotic disorders or other severe psychiatric disorders, establishing trust and rapport between session monitors and volunteer before the session, careful volunteer preparation, a safe physical session environment and interpersonal support from at least two study monitors during the session. Investigators should probe for the relatively rare hallucinogen persisting perception disorder in follow-up contact. Persisting adverse reactions are rare when research is conducted along these guidelines. Incautious research may jeopardize participant safety and future research. However, carefully conducted research may inform the treatment of psychiatric disorders, and may lead to advances in basic science.

Mystical-type experiences occasioned by psilocybin mediate the attribution of personal meaning and spiritual significance 14 months later

Psilocybin has been used for centuries for religious purposes; however, little is known scientifically about its long-term effects. We previously reported the effects of a double-blind study evaluating the psychological effects of a high psilocybin dose. This report presents the 14-month follow-up and examines the relationship of the follow-up results to data obtained at screening and on drug session days. Participants were 36 hallucinogen-naïve adults reporting regular participation in religious/ spiritual activities. Oral psilocybin (30 mg/70 kg) was administered on one of two or three sessions, with methylphenidate (40 mg/70 kg) administered on the other session(s). During sessions, volunteers were encouraged to close their eyes and direct their attention inward. At the 14-month follow-up, 58% and 67%, respectively, of volunteers rated the psilocybin-occasioned experience as being among the five most personally meaningful and among the five most spiritually significant experiences of their lives; 64% indicated that the experience increased well-being or life satisfaction; 58% met criteria for having had a 'complete' mystical experience. Correlation and regression analyses indicated a central role of the mystical experience assessed on the session day in the high ratings of personal meaning and spiritual significance at follow-up. Of the measures of personality, affect, quality of life and spirituality assessed across the study, only a scale measuring mystical experience showed a difference from screening. When administered under supportive conditions, psilocybin occasioned experiences similar to spontaneously occurring mystical experiences that, at 14-month follow-up, were considered by volunteers to be among the most personally meaningful and spiritually significant of their lives.

An algorithm for identifying nonsystematic delay-discounting data

Several [corrected] discounting studies have use the R2 measure to identify data [corrected] with poor fits to a mathematical discounting model as nonsystematic data to be eliminated [corrected] Data from three previous delay-discounting studies (six separate groups, with a total of 161 individuals) were used to demonstrate why using R2 to assess the fits of discounting data is problematic. A significant, positive correlation between discounting rate parameter and R2 was found in most groups, showing that R2 is more stringent as a measure of fit for low discounting rates than for high discounting rates. Furthermore, it is suggested that identifying nonsystematic data based on any measure of fit to a mathematical discounting model may be problematic because it confounds discounting rate comparison with the issue of discounting model assessment. Therefore, a model-free method to identify nonsystematic data is needed. An algorithm for identifying nonsystematic data is presented that is based on the expectation of a monotonically decreasing discounting function. This algorithm identified 13 cases out of the 161 reanalyzed data sets as nonsystematic. These nonsystematic data are presented, along with examples of data not identified as nonsystematic. This algorithm, or modifications of it, may be useful in a variety of human and nonhuman animal discounting studies (e.g., delay discounting, probability discounting) as an alternative to the R2 measure for identifying nonsystematic data. The algorithm may be used in empirical investigations to improve discounting methodology, and may be used to identify outliers to be removed from analyses.

Effects of citrus and avocado irrigation and nitrogen-form soil amendment on host selection by adult Homalodisca vitripennis (Hemiptera: Cicadellidae)

Host plant water status is thought to influence dispersal of the xylophagous leafhopper Homalodisca vitripennis Germar, especially where plants are grown under high evaporative demand. Preference by adult H. vitripennis for plants grown under different water deficit and nitrogen form fertilization regimens was studied under laboratory conditions. Leafhopper abundance and ovipositional preference were studied on potted 'Washington navel' orange and 'Haas' avocado in cage choice tests, and feeding rate was estimated using excreta produced by insects confined on plants. A similar study compared responses to citrus treated with 1:1 and 26:1 ratios of fertigated nitrate-N to ammonium-N. The insects were more abundant, oviposited, and fed significantly more on surplus-irrigated plants than on plants under moderate continuous deficit irrigation except avocado feeding, which was nearly significant. Plants exposed to drought became less preferred after 3 and 7 d in avocado and citrus, respectively. Citrus xylem fluid tension at this point was estimated at 0.93 MPa. A corresponding pattern of decline in feeding rate was observed on citrus, but on avocado, feeding rate was low overall and not statistically different between treatments. No statistical differences in abundance, oviposition, or feeding were detected on citrus fertigated with 26:1 or 1:1 ratios of nitrate-N to ammonium-N. Feeding occurred diurnally on both plant species. Discussion is provided on the potential deployment of regulated deficit irrigation to manage H. vitripennis movement as part of a multitactic effort to minimize the risk of disease outbreaks from Xylella fastidiosa Wells et al. in southern California agriculture.

Effect of salbutamol on respiratory muscle function and ventilation in awake canines

The effect of the beta-agonist bronchodilator salbutamol on respiratory muscles and ventilation is uncertain. The presence of beta2 receptors on skeletal muscles and increased diaphragm contractility in vitro with salbutamol predict a significant effect that has not been confirmed, in vivo in non-fatigued diaphragm or in clinical studies using standard bronchodilator dosages. Therefore, we infused salbutamol at a higher dosage (23.3 microg/min) used clinically for treatment of respiratory emergencies, while measuring directly the length, shortening and EMG activation of costal and crural diaphragm, parasternal intercostal and transversus abdominis muscles, in 10 awake canines. At this salbutamol dosage, ventilation and tidal volume increased significantly during both resting and CO2-stimulated breathing. Salbutamol elicited significant increases in respiratory muscle shortening with much smaller increases in EMG activity, so the proportionally greater muscle shortening per unit EMG showed increased muscle contractility. The effects of salbutamol were not extinguished by inspiratory flow resistance or fluid challenge but were reversed specifically by the beta-blocker, propranolol. This study demonstrates that, in sufficient intravenous dosage, the beta-agonist salbutamol elicits increased ventilation and a beta2 receptor-mediated increase in contractility of respiratory muscles.

Psyttalia ponerophaga (Hymenoptera: Braconidae) as a potential biological control agent of olive fruit fly Bactrocera oleae (Diptera: Tephritidae) in California

The olive fruit fly, Bactrocera oleae (Rossi), is a newly invasive, significant threat to California's olive industry. As part of a classical biological control programme, Psyttalia ponerophaga (Silvestri) was imported to California from Pakistan and evaluated in quarantine. Biological parameters that would improve rearing and field-release protocols and permit comparisons to other olive fruit fly biological control agents were measured. Potential barriers to the successful establishment of P. ponerophaga, including the geographic origins of parasitoid and pest populations and constraints imposed by fruit size, were also evaluated as part of this investigation. Under insectary conditions, all larval stages except neonates were acceptable hosts. Provided a choice of host ages, the parasitoids' host-searching and oviposition preferences were a positive function of host age, with most offspring reared from hosts attacked as third instars. Immature developmental time was a negative function of tested temperatures, ranging from 25.5 to 12.4 days at 22 and 30 degrees C, respectively. Evaluation of adult longevity, at constant temperatures ranging from 15 to 34 degrees C, showed that P. ponerophaga had a broad tolerance of temperature, living from 3 to 34 days at 34 and 15 degrees C, respectively. Lifetime fecundity was 18.7 +/- 2.8 adult offspring per female, with most eggs deposited within 12 days after adult eclosion. Olive size affected parasitoid performance, with lower parasitism levels on hosts feeding in larger olives. The implications of these findings are discussed with respect to field manipulation and selection of parasitoid species for olive fruit fly biological control in California and worldwide.

Moderate drug use and delay discounting: a comparison of heavy, light, and never smokers

Delay discounting was examined in light smokers (10 or fewer cigarettes per day) and compared with previously published delay discounting data for heavy and never smokers. Participants evaluated several hypothetical outcomes: money gains and loses ($10, $100, and $1,000), health gains and losses (durations of improved and impoverished health subjectively equivalent to $1,000), cigarette gains and losses (amounts subjectively equivalent to $1,000), and potentially real rewards ($10 and $100). Light smokers discounted money significantly more than never smokers, but light smokers did not differ from heavy smokers. The 3 groups did not statistically differ in discounting of health consequences. Similarly, the 2 smoking groups were not found to differ in discounting of cigarettes. Like heavy smokers, light smokers discounted cigarettes significantly more than money and health. Several significant, positive correlations were found between smoking rate and various discounting measures in the heavy smokers but not in the light smokers. Several previous findings were replicated, helping to validate the present results: the sign effect (greater discounting of gains than losses), the magnitude effect (greater discounting of smaller rewards), reliability of discounting measures over time, and the consistency of hypothetical and potentially real rewards. These data suggest that even moderate levels of drug use may be associated with high delay discounting levels.

Risk of dysplasia and adenocarcinoma following restorative proctocolectomy for ulcerative colitis

OBJECTIVE

Restorative proctocolectomy (RPC) with or without mucosectomy is the treatment of choice for most patients with ulcerative colitis (UC) requiring surgery. The ileal mucosa in the reservoir and the anorectal columnar epithelium below the ileo-anal anastomosis are at risk of neoplastic transformation.

METHOD

The literature has been reviewed to identify patients developing this complication and an attempt has been made to develop a rational follow-up policy based on the data available.

RESULTS

Dysplasia in the ileal reservoir is rare. It is associated with histological type C changes, sclerosing cholangitis and unremitting pouchitis in the ileal mucosa and to the presence of sclerosing cholangitis. Nine patients who have developed adenocarcinoma in the residual anorectal mucosa and seven in the reservoir have been reported in the literature. A further hitherto unreported patient treated by the authors brings the total to 17 patients. Twelve of these had histopathological data on either dysplasia or carcinoma in the original operative specimen. The time intervals from the onset of UC and from the RPC to the development of cancer were 120-528 (median 246) and 16-216 (median 60) months respectively. Cancer appeared to be related to the duration of disease rather than to the interval from RPC. In all the reported patients the interval from the onset of UC was 10 years.

CONCLUSION

Based on these data a surveillance programme should begin at 10 years from the onset of disease. Patients with dysplasia or carcinoma in the original specimen, those with type C ileal mucosal changes and patients with sclerosing cholangitis should be selected for surveillance. This will involve multiple biopsies of the ileal reservoir and the anorectal mucosa below the ileo-anal anastomosis.

Ramelteon: a novel hypnotic lacking abuse liability and sedative adverse effects

CONTEXT

Ramelteon is a novel MT1 and MT2 melatonin receptor selective agonist recently approved for insomnia treatment. Most approved insomnia medications have potential for abuse and cause motor and cognitive impairment.

OBJECTIVE

To evaluate the potential for abuse, subjective effects, and motor and cognitive-impairing effects of ramelteon compared with triazolam, a classic benzodiazepine sedative-hypnotic drug.

DESIGN

In this double-blind crossover study, each participant received oral doses of ramelteon (16, 80, or 160 mg), triazolam (0.25, 0.5, or 0.75 mg), and placebo during approximately 18 days. All participants received each treatment on different days. Most outcome measures were assessed at 0.5 hours before drug administration and repeatedly up to 24 hours after drug administration.

SETTING

Residential research facility.

PARTICIPANTS

Fourteen adults with histories of sedative abuse.

MAIN OUTCOME MEASURES

Subject-rated measures included items relevant to potential for abuse (eg, drug liking, street value, and pharmacological classification), as well as assessments of a broad range of stimulant and sedative subjective effects. Observer-rated measures included assessments of sedation and impairment. Motor and cognitive performance measures included psychomotor and memory tasks and a standing balance task.

RESULTS

Compared with placebo, ramelteon (16, 80, and 160 mg) showed no significant effect on any of the subjective effect measures, including those related to potential for abuse. In the pharmacological classification, 79% (11/14) of subjects identified the highest dose of ramelteon as placebo. Similarly, compared with placebo, ramelteon had no effect at any dose on any observer-rated or motor and cognitive performance measure. In contrast, triazolam showed dose-related effects on a wide range of subject-rated, observer-rated, and motor and cognitive performance measures, consistent with its profile as a sedative drug with abuse liability.

CONCLUSION

Ramelteon demonstrated no significant effects indicative of potential for abuse or motor and cognitive impairment at up to 20 times the recommended therapeutic dose and may represent a useful alternative to existing insomnia medications.