Psychedelics: Threshold of a Therapeutic Revolution.

This Special Issue of Neuropharmacology on psychedelics provides a timely and comprehensive update on progress following the previous Neuropharmacology Special Issue "Psychedelics: New Doors, Altered Perceptions". Remarkable advances have been made in basic and clinical research on psychedelics in the five years since 2018. It is partly based on the seminar series focused on psilocybin organized by the National Institutes of Health (NIH), USA from April to June 2021, the "NIH Psilocybin Research Speaker Series". Participants were world leading experts, including scientists, medical practitioners, clinical psychologists and oncologists, and attendees from additional disciplines of patient advocacy, law, government science policy and regulatory policy. To provide a global perspective, their contributions are complemented with reviews by some of the world's most eminent scientists in the field. The US Food and Drug Administration (FDA) has granted two breakthrough therapy designations for psilocybin in treatment resistant depression (TRD) in 2018 and major depressive disorder (MDD) in 2019, as well as for MDMA for the treatment of post-traumatic stress disorder (PTSD) in 2017. Clinical trials are in progress to assess the therapeutic value of psilocybin in MDD and TRD, and in other indications such as cancer-related anxiety and depression, anorexia, PTSD, substance use disorders and various types of chronic pain. The contributors' insights should assist basic and applied science for transition of psychedelics from bench to potential mainstream therapies. The implications are global, because FDA approval of these new medicines will increase international interest and efforts.

Psychedelic-assisted psychotherapy to treat psychiatric and existential distress in life-threatening medical illnesses and palliative care.

Psychiatric and existential distress commonly occur in advanced cancer and other serious, life-threatening or end-of-life medical illnesses and are associated with poor medical and psychiatric outcomes. Currently available treatment modalities in this patient population, including medication and psychotherapy, are limited in effectiveness, especially regarding existential distress. The lack of effective psycho-spiritual interventions is a critical shortcoming in palliative care and represents a high unmet need in medicine. In this commentary, we review the rationale of researching and developing psychedelic-assisted psychotherapy as a novel pharmacologic-psychotherapeutic intervention to treat psychiatric and existential distress in life-threatening medical conditions and palliative care. This paper reviews efficacy data from first and second waves of psychedelic research, and future directions for research and implementation science. More rigorous research, especially funded by governments, is needed to assess effectiveness and mechanisms of action of psychedelic therapies to treat psychiatric and existential distress in life-threatening medical illnesses and palliative care. If psychedelic-assisted treatments were made available as approved and prescribable medications in people with serious medical illnesses, it could be a significant development that opens up a pathway for clinical dissemination and public health impact internationally.

The scientific basis of tobacco product regulation.

This report presents the conclusions and recommendations of TobReg from its fourth meeting, where the Study Group deliberated on a number of topics in the field of tobacco product regulation and produced the following advisory notes and recommendations: an advisory note on smokeless tobacco products: health effects, implications for harm reduction and research needs; an advisory note on 'fire safer' cigarettes: approaches to reduced ignition propensity; a recommendation on mandated lowering of toxicants in cigarette smoke: tobacco-specific nitrosamines and selected other constituents; and a recommendation on cigarette machine smoking regimens. The four sections of this report address these four issues, and the Study Group's recommendations are set out at the end of each section. Its overall recommendations are summarized in section 5.

Brand differences of free-base nicotine delivery in cigarette smoke: the view of the tobacco industry documents.

The recent availability of internal tobacco industry documents provides significant insight into industry knowledge and manipulation of tobacco smoke delivery. One critical area of research is the role of smoke chemistry in determining the absorption and effects of smoke constituents, especially harm producing or pharmacologically active compounds. Independent scientific research has suggested that the nicotine dosing characteristics, hence the addiction potential of cigarettes, may be determined in part by the amount of free-base nicotine in cigarette smoke and its effects on the location, route, and speed of absorption in the body and on the sensory perception effects of the inhaled smoke. Tobacco industry documents describe the use of a number of methods internally for measuring free-base nicotine delivery. These include the common use of cigarette "smoke pH" as a means to estimate the fraction of free-base nicotine in the particulate matter (PM) in cigarette smoke, as well as efforts to measure free-base nicotine directly. Although these methods do not provide accurate absolute measures of free-base nicotine in smoke, consistencies observed in the findings across the various manufacturers indicate: (1) real relative differences in the acid/base chemistry of the smoke from different brands of cigarettes; (2) a connection between differences in free-base levels and brand-dependent differences in sensory perception and smoke "impact"; and (3) levels of free-base nicotine that are greater than have typically been publicly discussed by the industry. Furthermore, the results of these methods are generally consistent with those of a recent study from the Centers for Disease Control and Prevention which directly measured the free-base fraction of nicotine across a range of cigarette types. Consideration of the likely fundamental importance of free-base nicotine levels in cigarette smoke, together with the efforts discussed in the tobacco industry documents to measure such levels, indicates that the public health community would benefit from additional research to assess directly the delivery of free-base nicotine in cigarette smoke across brands. This may be especially useful for those products ("light", "ultralight", "reduced carcinogen", etc) that have been promoted, either explicitly or implicitly, as "harm reducing".

Toward a comprehensive long term nicotine policy.

Global tobacco deaths are high and rising. Tobacco use is primarily driven by nicotine addiction. Overall tobacco control policy is relatively well agreed upon but a long term nicotine policy has been less well considered and requires further debate. Reaching consensus is important because a nicotine policy is integral to the target of reducing tobacco caused disease, and the contentious issues need to be resolved before the necessary political changes can be sought. A long term and comprehensive nicotine policy is proposed here. It envisages both reducing the attractiveness and addictiveness of existing tobacco based nicotine delivery systems as well as providing alternative sources of acceptable clean nicotine as competition for tobacco. Clean nicotine is defined as nicotine free enough of tobacco toxicants to pass regulatory approval. A three phase policy is proposed. The initial phase requires regulatory capture of cigarette and smoke constituents liberalising the market for clean nicotine; regulating all nicotine sources from the same agency; and research into nicotine absorption and the role of tobacco additives in this process. The second phase anticipates clean nicotine overtaking tobacco as the primary source of the drug (facilitated by use of regulatory and taxation measures); simplification of tobacco products by limitation of additives which make tobacco attractive and easier to smoke (but tobacco would still be able to provide a satisfying dose of nicotine). The third phase includes a progressive reduction in the nicotine content of cigarettes, with clean nicotine freely available to take the place of tobacco as society's main nicotine source.

Reducing tobacco addiction through tobacco product regulation.

Tobacco product regulation has the potential to help reduce tobacco attributable disease by reducing the toxicity of these products and by reducing the prevalence of tobacco use and addiction.

Regulatory strategies to reduce tobacco addiction in youth.

Preventing tobacco addiction and achieving cessation in established users are the cornerstones of efforts to reduce tobacco use and disease. It has been increasingly recognised that reducing tobacco toxin exposure has theoretical potential to reduce disease in continuing tobacco users. This has been controversial because such approaches also carry the potential to undermine prevention and cessation. As complicated as harm reduction issues are for adults, they are still more complicated for youth. Harm reduction is not a singular approach, but rather a concept that encompasses an extremely diverse array of potential approaches. These carry equally diverse potential risks and benefits. The regulatory framework (for example, whether or not the Food and Drug Administration regulates the approach) is also predicted to be a major factor in determining the consequences of harm reduction approaches. This paper examines the various issues and potential approaches concerning the application of harm reduction to youth. We conclude that although some carry great risk, others may actually support broader tobacco control efforts to prevent tobacco use and foster cessation in youth and adults.

Correlates of expired air carbon monoxide: effect of ethnicity and relationship with saliva cotinine and nicotine.

AIMS: To assess the accuracy of expired air carbon monoxide (CO) measurement vs. saliva cotinine and nicotine and to estimate the degree of misclassifications of smoking status as a function of ethnicity. DESIGN AND MEASUREMENTS: Comparison for accuracy of expired air CO, saliva nicotine and cotinine in simultaneously collected specimens. SETTING: Outpatient clinic of a clinical research ward. PARTICIPANTS: 228 current African-American and Caucasian cigarette smokers. RESULTS: Expired-air CO concentration was significantly associated with saliva cotinine, but not with saliva nicotine. Saliva cotinine but not expired CO or saliva nicotine showed a significant between-ethnic difference when adjusted for number of cigarettes smoked and for time since last cigarette. Agreement between expired air CO and saliva cotinine was substantial at expired CO < or = 8 ppm but only moderate at < or = 10 ppm. False negative rates were twice as high at < or = 10 ppm than at < or = 8 ppm at each saliva cotinine cut-off tested. At saliva cotinine of < or = 15 ng/ml, more African-Americans were classified as false negative. CONCLUSIONS: Expired CO is strongly associated with saliva cotinine but not with saliva nicotine. Despite this association, misclassifications for no smoking are frequent if true classification is based on saliva cotinine. False negative results occur more frequently in African-Americans.

Combination nicotine replacement therapy for smoking cessation: rationale, efficacy and tolerability.

Currently available nicotine replacement therapy (NRT) medications provide effective treatment for tobacco dependence, typically doubling success rates compared with placebo. A strategy for further improving the efficacy of NRT is to combine one medication that allows for passive nicotine delivery (e.g. transdermal patch) with another medication that permits ad libitum nicotine delivery (e.g. gum, nasal spray, inhaler). The rationale for combining NRT medications is that smokers may need both a slow delivery system to achieve a constant concentration of nicotine to relieve cravings and tobacco withdrawal symptoms, as well as a faster acting preparation that can be administered on demand for immediate relief of breakthrough cravings and withdrawal symptoms. This article reviews 5 published studies that have examined the effectiveness of combination NRT compared with monotherapy in providing withdrawal relief and smoking cessation, and examines other factors relevant to the promotion of combination NRT for treating tobacco dependence. The data show that there are conditions under which combinations of NRT products provide greater efficacy in relieving withdrawal and enabling cessation than monotherapy, but the findings are not robust and additional research is warranted to better understand the magnitude and generality of the benefits of combination therapy. There are also regulatory and commercial obstacles that must be considered. Nonetheless, combination NRT has the potential to provide effective treatment of tobacco dependence in persons whose dependence is refractory to currently available treatments.

A factor analysis of the fagerstrom tolerance questionnaire.

A factor analysis of 1309 Fagerstrom Tolerance Questionnaires (FTQ) was performed with LISCOMP software, which utilizes tetrachoric correlations to account for the dichotomous responses of the FTQ. Three factors with eigenvalues greater than 1.0 were obtained, accounting for 56.6% of the variance. Factor 1 was loaded by questions "How soon on waking do you smoke your first cigarette?," "Do you find it difficult to refrain from smoking in places it is forbidden?," "How many cigarettes a day do you smoke?," and "Do you smoke if you are so ill that you are in bed most of the day?" Factor 2 was loaded by questions "Which cigarette would you hate to give up?" and "Do you smoke more during the morning than during the rest of the day?" Factor 3 was loaded exclusively by question "What brand do you smoke?" The question "Do you inhale always, sometimes, or never?" loaded exclusively on a fourth factor, however its eigenvalue did not reach significance. Support is provided for the modification of the eight-item FTQ to the six-item Fagerstrom Test for Nicotine Dependence (FTND). Based on the wording of the questions that loaded on each factor, we propose that Factor 2 assesses the degree of urgency to initiate smoking after overnight abstinence and that Factor 1 reflects the persistence of smoking during waking hours.

Effect of nicotine on brain activation during performance of a working memory task.

Nicotine influences cognition and behavior, but the mechanisms by which these effects occur are unclear. By using positron emission tomography, we measured cognitive activation (increases in relative regional cerebral blood flow) during a working memory task [2-back task (2BT)] in 11 abstinent smokers and 11 ex-smokers. Assays were performed both after administration of placebo gum and 4-mg nicotine gum. Performance on the 2BT did not differ between groups in either condition, and the pattern of brain activation by the 2BT was consistent with reports in the literature. However, in the placebo condition, activation in ex-smokers predominated in the left hemisphere, whereas in smokers, it occurred in the right hemisphere. When nicotine was administered, activation was reduced in smokers but enhanced in ex-smokers. The lateralization of activation as a function of nicotine dependence suggests that chronic exposure to nicotine or withdrawal from nicotine affects cognitive strategies used to perform the memory task. Furthermore, the lack of enhancement of activation after nicotine administration in smokers likely reflects tolerance.

Tobacco addiction and pharmacological interventions.

Even though its health consequences are well known, tobacco use continues to kill millions of smokers worldwide every year. In the US alone, tobacco use kills > 430,000 people each year. The global mortality toll is approximately 5 million annually and this is increasing. It is the powerful grip of tobacco addiction that sustains high levels of daily smoke intake and persistent smoking, with > 90% of all cigarette smokers who quit, resuming smoking within 1 year. Tobacco addiction, which places tremendous health and economic burdens on individual societies, is also becoming a global epidemic. Although tobacco addiction is a complex phenomenon, it is treatable and several effective medications are now available. In the mid-1980s, the US FDA approved nicotine gum, the first of these effective pharmacological aids. Other effective medications have subsequently become available, including nicotine transdermal patches, nasal spray, oral vapour inhaler, sublingual nicotine tablets and bupropion. These medications and the potential for development of new medications will be reviewed.

Tolerance to repeated nicotine administration on performance, subjective, and physiological responses in nonsmokers.

RATIONALE: When administered acutely to nonsmokers, nicotine's effects on performance are inconsistent, perhaps because of suboptimal dosing or initial dysphoria that could interfere with performance. OBJECTIVE: The purpose of this study was to determine if a range of nicotine doses administered for 8 days to nonsmokers would enhance psychomotor and cognitive abilities and to document the development of nicotine tolerance or sensitization. METHODS: Twelve male volunteers, who reported ever smoking five cigarettes or less, participated in 8 consecutive experimental days in which they were administered four doses of nicotine polacrilex gum each day in this order: 0, 2, 4, and 8 mg. Performance, subjective, and physiological measures were assessed before and after each dose. RESULTS: Plasma nicotine concentration ranged from 6.9 to 11.5 ng/ml following the 8 mg dose. Nicotine increased rate of responding and decreased response time on working memory (digit recall); however, accuracy was impaired. Nicotine also decreased accuracy on visual scanning and attention (two-letter search), and the 8 mg dose impaired gross motor coordination (circular lights). Tolerance did not develop to the performance impairing effects of nicotine. Nicotine produced dose-related increases in ratings of dysphoria and negative mood, including tension, anxiety, nervousness, turning of stomach, and sedation. Tolerance developed to some, but not all, of these aversive effects. Tolerance also was not observed to the increased cardiovascular measures. CONCLUSION: Although tolerance developed to some of the aversive effects of nicotine, performance enhancement was not observed. These data do not support the hypothesis that nicotine-induced performance enhancement contributes to the reinforcing effects of tobacco use during the early stages of dependence development.

Behavioral and pharmacological treatment methods for pregnant smokers: issues for clinical practice.

Active and passive exposure to tobacco smoke are the most serious and preventable causes of poor maternal, fetal, and infant outcomes in the United States. Unfortunately, the majority of pregnant smokers do not quit smoking before or during pregnancy or after childbirth. We describe a standardized behavioral counseling model and discuss issues to consider in recommending the use of pharmacotherapy during pregnancy. Although the Food and Drug Administration no longer classifies nicotine replacement therapy (NRT) as contraindicated during pregnancy, precautions should be carefully considered for use in this population. This paper provides a synopsis of the risks of exposure to tobacco smoke during pregnancy and the postpartum; estimates the population at risk and the potential for increased cessation if effective health education methods during pregnancy were routinely provided; presents a meta-analysis of "best practice" patient education methods for pregnant smokers; and estimates the number of pregnant heavy smokers who might be eligible for NRT. We suggest five issues for the physician to consider before recommending NRT medications to pregnant patients who are heavy smokers. The judicious use of NRT medications may significantly reduce harm to the infants of heavy smokers. More evidence derived from large population-based research, however, is needed to provide guidance to the physician about NRT eligibility, dose, scheduling, and effectiveness in clinical practice.

Health risks associated with cigar smoking.

This article summarizes principal findings from a conference convened by the American Cancer Society in June 1998 to examine the health risks of cigar smoking. State-of-the-science reports were presented and 120 attendees (representing government and private agencies, academia, health educators, and tobacco control experts) participated in panels and summary development discussions. The following conclusions were reached by consensus: (1) rates of cigar smoking are rising among both adults and adolescents; (2) smoking cigars instead of cigarettes does not reduce the risk of nicotine addiction; (3) as the number of cigars smoked and the amount of smoke inhaled increases, the risk of death related to cigar smoking approaches that of cigarette smoking; (4) cigar smoke contains higher concentrations of toxic and carcinogenic compounds than cigarettes and is a major source of fine-particle and carbon monoxide indoor air pollution; and (5) cigar smoking is known to cause cancers of the lung and upper aerodigestive tract. JAMA. 2000;284:735-740

Mecamylamine blockade of both positive and negative effects of IV nicotine in human volunteers.

The ganglionic blocker mecamylamine blocks the positive reinforcing effects of IV nicotine, but has been shown to increase cigarette smoking behavior under some conditions. The effects of mecamylamine on subjective and physiologic responses to IV nicotine were evaluated in seven healthy male volunteer cigarette smokers who provided informed consent and resided on a clinical pharmacology research unit. On four separate days, each subject was given a different oral dose of mecamylamine (placebo, 5, 10, or 20 mg). One hour later subjects received the first of four doses of IV nicotine (placebo, 0.75, 1.5, and 3.0 mg); the remaining injections were given at 1-h intervals. Both the positive effects following 0.75 mg and negative effects following 3.0 mg of nicotine were significantly reversed by mecamylamine. Thus, the mecamylamine-induced increase in smoking may be due both to competitive blockade of nicotinic receptors and nicotine's reversal of aversive effects.