Meta-analysis of the acute effects of nicotine and smoking on human performance

The Role of Cognitive Control in the Self-Regulation and Reinforcement of Smoking Behavior

Cognitive control (CC)-the ability to regulate attention and memory-plays an important role in a variety of health behaviors, including smoking behavior. In this theoretical review of the literature, we propose a CC and smoking behavior framework that includes (1) the positive influence of CC on the self-regulation of smoking, (2) nicotine-induced improvements in CC that may indirectly reinforce smoking (including withdrawal reversal effects), and (3) the long-term effects of smoking on the brain that may result in reduced CC. Integration of these literatures suggests that CC contributes to both self-regulation (ie, brake pedal) and nicotine-related reinforcement (ie, gas pedal) amid the catastrophic effects of long-term smoking, which may reduce self-regulatory control over smoking while also enhancing indirect reinforcement. Supportive evidence and limitations of this approach will be presented, as well as ideas for future research directions that may fully examine this multifaceted modeling of CC in relation to smoking behavior.

IMPLICATIONS

There is substantial evidence that CC contributes to self-regulation (ie, brake pedal) and reinforcement (ie, gas pedal) of smoking behavior as well as evidence that long-term smoking may cause reduced CC. The proposed model delineates how these opposing influences of CC may mask the unique contribution of self-regulation and reinforcement in maintaining smoking behavior. Targeting CC for treating nicotine dependence will require more nuanced approaches that consider the independent and combined effects of self-regulation and reinforcement to improve smoking cessation success rates.

Gender Moderates Chronic Nicotine Cigarette Effects on Verbal Memory in Young Adults

Background: Rates of nicotine use remain a prominent public health concern, especially among young adults. Previous findings have demonstrated that chronic exposure to nicotine during adolescence may be linked to various neurocognitive deficits. Nicotine differentially affects the brain by gender. Objectives: The present study investigated the effects of gender and chronic nicotine use on cognition in the developing brain. Methods: From 2008 to 2011, 57 young adult (ages 18-25) participants were recruited as part of a larger cross-sectional neuroimaging study and divided into 21 nicotine users (12 female) and 36 non-using controls (17 female). Participants completed various questionnaires, drug use interview, neuropsychological battery, and MRI scan in a university setting. A series of multiple regressions was conducted with nicotine group and gender*nicotine group interaction as predictors. Results: After controlling for gender, nicotine group status alone was not associated with neuropsychological performance. A gender x nicotine interaction was significantly associated with performance on trial 1, short delay free recall, and long delay free recall of the CVLT-II. Female smokers demonstrated better performance on trial 1 and short and long delay free recall than female controls. Male smokers performed more poorly than male controls on short and long delay free recall. Conclusions: These preliminary findings suggest that cognitive effects of chronic nicotine use are moderated by gender. Further research is needed to determine causality, and identify underlying brain structures and function that may be responsible for differences in verbal memory.

Attention Measures of Accuracy, Variability, and Fatigue Detect Early Response to Donepezil in Alzheimer's Disease: A Randomized, Double-blind, Placebo-Controlled Pilot Trial

OBJECTIVE

Donepezil is widely used to treat Alzheimer's disease (AD), but detecting early response remains challenging for clinicians. Acetylcholine is known to directly modulate attention, particularly under high cognitive conditions, but no studies to date test whether measures of attention under high load can detect early effects of donepezil. We hypothesized that load-dependent attention tasks are sensitive to short-term treatment effects of donepezil, while global and other domain-specific cognitive measures are not.

METHOD

This longitudinal, randomized, double-blind, placebo-controlled pilot trial (ClinicalTrials.gov Identifier: NCT03073876) evaluated 23 participants newly diagnosed with AD initiating de novo donepezil treatment (5 mg). After baseline assessment, participants were randomized into Drug (n = 12) or Placebo (n = 11) groups, and retested after approximately 6 weeks. Cognitive assessment included: (a) attention tasks (Foreperiod Effect, Attentional Blink, and Covert Orienting tasks) measuring processing speed, top-down accuracy, orienting, intra-individual variability, and fatigue; (b) global measures (Alzheimer's Disease Assessment Scale-Cognitive Subscale, Mini-Mental Status Examination, Dementia Rating Scale); and (c) domain-specific measures (memory, language, visuospatial, and executive function).

RESULTS

The Drug but not the Placebo group showed benefits of treatment at high-load measures by preserving top-down accuracy, improving intra-individual variability, and averting fatigue. In contrast, other global or cognitive domain-specific measures could not detect treatment effects over the same treatment interval.

CONCLUSIONS

The pilot-study suggests that attention measures targeting accuracy, variability, and fatigue under high-load conditions could be sensitive to short-term cholinergic treatment. Given the central role of acetylcholine in attentional function, load-dependent attentional measures may be valuable cognitive markers of early treatment response.

Alterations in resting-state functional connectivity in substance use disorders and treatment implications

Substance use disorders (SUD) are diseases of the brain, characterized by aberrant functioning in the neural circuitry of the brain. Resting state functional connectivity (rsFC) can illuminate these functional changes by measuring the temporal coherence of low-frequency fluctuations of the blood oxygenation level-dependent magnetic resonance imaging signal in contiguous or non-contiguous regions of the brain. Because this data is easy to obtain and analyze, and therefore fairly inexpensive, it holds promise for defining biological treatment targets in SUD, which could help maximize the efficacy of existing clinical interventions and develop new ones. In an effort to identify the most likely "treatment targets" obtainable with rsFC we summarize existing research in SUD focused on 1) the relationships between rsFC and functionality within important psychological domains which are believed to underlie relapse vulnerability 2) changes in rsFC from satiety to deprived or abstinent states 3) baseline rsFC correlates of treatment outcome and 4) changes in rsFC induced by treatment interventions which improve clinical outcomes and reduce relapse risk. Converging evidence indicates that likely "treatment target" candidates, emerging consistently in all four sections, are reduced connectivity within executive control network (ECN) and between ECN and salience network (SN). Other potential treatment targets also show promise, but the literature is sparse and more research is needed. Future research directions include data-driven prediction analyses and rsFC analyses with longitudinal datasets that incorporate time since last use into analysis to account for drug withdrawal. Once the most reliable biological markers are identified, they can be used for treatment matching, during preliminary testing of new pharmacological compounds to establish clinical potential ("target engagement") prior to carrying out costly clinical trials, and for generating hypotheses for medication repurposing.

Dissociating the effect of flavor and nicotine in smokeless tobacco products using electroencephalography: The case of wintergreen flavors

The increased consumption of tobacco products in recent years has been linked, among other factors, to the presence of added flavors. Although flavors are important in explaining consumption, their effects in the brain have until now been unexplored. In the present study, we investigated how electrophysiology can serve to dissociate the effects of nicotine and flavor. Participants attended 4 sessions (2-by-2 factorial design, with flavor and nicotine as within-subject factors), in each session an oddball task was performed before and after smokeless tobacco consumption. We explored the dissociation of neural responses to flavor and nicotine. While event-related potentials did not show modulation due to flavors, time-frequency showed a flavor-nicotine dissociation. Low-frequency activity (delta, theta and alpha) showed only effects of nicotine, and high-frequency activity (beta1, beta2 and gamma) showed effects only susceptible to flavor. Flavors in smokeless tobacco not only made the product more desirable but also triggered the allocation of cognitive resources. This long-lasting effect of flavor may enhance the addictive potential of the tobacco product. Further research is being developed to determine the precise role of flavors in contributing to addiction. This is the first study investigating the neural effects of flavor (specifically wintergreen) in smokeless tobacco products. By understanding the effects of flavors in the brain we can explain the precipitants of tobacco consumption behaviors, and the addictive potential of flavors. Regulators will be able to determine if and in which amount flavors should be allowed in tobacco products.

Re: Disregarding the impact of nicotine on the developing brain when evaluating costs and benefits of noncombustible nicotine products

This Letter to the Editor is in response to a letter from Ms. Flannery, titled, "Disregarding the impact of nicotine on the developing brain when evaluating costs and benefits of noncombustible nicotine products". In our response, we address some concerns raised by Ms. Flannery, and reiterate our position in our original article. In particular, we underline the importance of a rational public health calculus that weighs beneficial and harmful consequences of policies related to noncombustible nicotine product (NNP) use. We further emphasize the need to correct misperceptions about relative risk of different products to encourage smokers to switch to NNPs. Lastly, we are explicit about our assertion that no use of any nicotine-containing products is the only way to avoid harm at any age, but that we must view this issue pragmatically for the benefit of public health.

Tobacco Use in Fibromyalgia Is Associated With Cognitive Dysfunction: A Prospective Questionnaire Study

Objective

To evaluate the association between smoking and cognitive function in patients with fibromyalgia.

Patients and Methods

We surveyed 668 patients with fibromyalgia from May 1, 2012 through November 30, 2013 at a major tertiary referral center. Patients were categorized by smoking status. Primary outcome of interest was cognitive function (MASQ questionnaire), and secondary outcomes included fibromyalgia symptom severity (FIQ-R questionnaire), quality of life (SF-36 questionnaire), fatigue (MFI-20 questionnaire), sleep (MOS-sleep scale), anxiety (GAD-7 questionnaire), and depression (PHQ-9 questionnaire). Independent Students' t-tests and χ² tests were performed for continuous and categorical variables, respectively. Univariate regression analysis identified variables predictive of outcomes, adjusting for age, gender, body mass index, marital status, and educational level.

Results

Ninety-four (14.07%) patients self-identified as smokers. There was an association of lower education level, unmarried status, and younger age in smokers compared with nonsmokers. In the adjusted univariate regression analysis, fibromyalgia smokers reported greater perceived total cognitive dysfunction (P=.009) and greater subscale scores of perceived difficulty in language (P=.03), verbal memory (P=.003), visual-spatial memory (P=.02), and attention (P=.04) compared with nonsmokers with fibromyalgia. For secondary outcomes, smokers with fibromyalgia reported greater severity of fibromyalgia-related symptoms (P=.006), worse quality-of-life index in the mental component scale (P=.02), greater sleep problems (P=.01), and increased anxiety (P=.001) compared with nonsmokers who had fibromyalgia.

Conclusion

In patients with fibromyalgia, smoking is a risk factor for cognitive dysfunction. Moreover, smokers with fibromyalgia were more likely to report increased severity of fibromyalgia symptoms, worse quality of life, more sleep problems, and increased anxiety compared with nonsmokers with fibromyalgia.

Predictors of virtual reality simulation bronchoscopy performance among novice bronchoscopists

INTRODUCTION

Simulation-based training is gradually replacing the classic "apprenticeship" training model. Predictors of better performance of virtual reality simulation bronchoscopy are not clear.

OBJECTIVE

We aim to explore the predictors of performance of simulation bronchoscopy among novice bronchoscopists.

MATERIALS AND METHODS

This is a descriptive observational cohort study conducted at King Abdulaziz University Clinical Skills and Simulation Center, Jeddah, Saudi Arabia. All participants filled a demographic questionnaire and attended a pre-simulation orientation about the requested tasks. The Simbionix bronchoscopy simulator was used in this study. First, each resident performed three trails of basic scope manipulation task to test hand-eye coordination skills. Thereafter, each resident performed the guided anatomical navigation task to accurately examine as many lung segments as possible. Results and metrics were retrieved from the simulator, and statistical analysis was performed using t-test to measure statistically significant P-value (<0.05).

RESULTS

Fifty-three internal medicine residents participated in this study. Male residents significantly achieved higher score in the basic scope manipulation task than female residents (65% vs 46%, P<0.001). Furthermore, the percentage of time spent at mid lumen during the scope manipulation was significantly higher for males compared to female residents (48% vs 37%, P=0.003). Residents who were interested in pursuing procedure-based specialty training spent significantly less time in contact with wall (14.6% vs 20.3%, P=0.045). Smokers needed more time to finish the first task (mean 2.5 minutes vs mean 1.1 minutes, P=0.005).

CONCLUSION

Simulation bronchoscopy performance was different between genders, smoking status and future interest in pursuing a procedure-based career. Overall, male residents performed better than female residents in basic scope manipulation. Gender differences in performing simulation bronchoscopy need to be examined in future studies. Tailored educational programs may be needed to fit gender-specific skills and requirements as well as future career interests.

Tobacco smoking and its drug interactions with comedications involving CYP and UGT enzymes and nicotine

Tobacco smoking is a global public health threat causing several illnesses including cardiovascular disease (Myocardial infarction), cerebrovascular disease (Stroke), peripheral vascular disease (Claudication), chronic obstructive pulmonary disease, asthma, reduced female infertility, sexual dysfunction in men, different types of cancer and many other diseases. It has been estimated in 2015 that approximately 1.3 billion people smoke, around the globe. Use of medications among smokers is more common, nowadays. This review is aimed to identify the medications affected by smoking, involving Cytochrome P450 (CYP) and uridine diphosphate-glucuronosyltransferases (UGTs) enzymes and Nicotine. Polycyclic aromatic hydrocarbons (PAHs) of tobacco smoke have been associated with the induction of CYP enzymes such as CYP1A1, CYP1A2 and possibly CYP2E1 and UGT enzymes. The drugs metabolized by CYP1A1, CYP1A2, CYP2E1 and UGT enzymes might be affected by tobacco smoking and the smokers taking medications metabolized by those enzymes, may need higher doses due to decreased plasma concentrations through enhanced induction by PAHs of tobacco smoke. The prescribers and the pharmacists are required to be aware of medications affected by tobacco smoking to prevent the toxicity-associated complications during smoking cessation.

Employee Psychoactive Substance Involvement: Historical Context, Key Findings, and Future Directions

Humans have consumed psychoactive substances for millennia, and these substances have played an important role in human culture and human labor. This article investigates our current understanding of the general association between the workplace and employee involvement with psychoactive substances. I begin by briefly exploring the broad evolutionary and historical intersection of psychoactive substances, human culture, and human labor. I then outline the multidimensional nature of employee psychoactive substance involvement and look at its prevalence. Next, I summarize recent research on workplace antecedents, such as work stressors, substance availability, norms, and social control. I then summarize research on the adverse workplace outcomes experienced by employees who use psychoactive substances as well as the collateral effects of such use on coworkers. Throughout the article, I identify directions for future research.

Effects of smoking on cognition and BDNF levels in a male Chinese population: relationship with BDNF Val66Met polymorphism

Recent studies demonstrate that brain-derived neurotrophic factor (BDNF) might be associated with nicotine addiction, and circulating BDNF is a biomarker of memory and general cognitive function. Moreover, studies suggest that a functional polymorphism of the BDNF Val66Met may mediate hippocampal-dependent cognitive functions. We aimed to explore the relationships between smoking, cognitive performance and BDNF in a normal Chinese Han population. We recruited 628 male healthy subjects, inducing 322 smokers and 306 nonsmokers, and genotyped them the BDNF Val66Met polymorphism. Of these, we assessed 114 smokers and 98 nonsmokers on the repeatable battery for the assessment of neuropsychological status (RBANS), and 103 smokers and 89 nonsmokers on serum BDNF levels. Smokers scored lower than the nonsmokers on RBANS total score (p = 0.002), immediate memory (p = 0.003) and delayed memory (p = 0.021). BDNF levels among the smokers who were Val allele carriers were correlated with the degree of cognitive impairments, especially attention, as well as with the carbon monoxide concentrations. Our findings suggest that smoking is associated with cognitive impairment in a male Chinese Han population. The association between higher BDNF levels and cognitive impairment, mainly attention in smokers appears to be dependent on the BDNF Val66Met polymorphism.

Recent Updates in Animal Models of Nicotine Withdrawal: Intracranial Self-Stimulation and Somatic Signs

Tobacco use is one of the leading causes of disease, disability, and death in the world. Despite the negative health consequences of smoking and the fact that most people would like to quit, very few people are able to maintain abstinence. Nicotine, the main psychoactive component of tobacco, is mildly rewarding and plays a role in the initiation and maintenance of smoking. Cessation of nicotine intake induces mild somatic withdrawal symptoms that may contribute to the maintenance of smoking. However, it has been hypothesized that negative affective nicotine withdrawal signs are of greater motivational significance in contributing to relapse and continued smoking (Markou and Koob (eds) Intracranial self-stimulation thresholds as a measure of reward, vol 2. Oxford University Press, New York, 1993; Koob et al., Semin Neurosci 5:351-358, 1993). Intracranial self-stimulation (ICSS) has been established as a method to assess the acute rewarding properties of nicotine and the dysphoria associated with nicotine withdrawal. The ICSS method provides a means to measure the negative affective aspects of nicotine withdrawal in animal models and may contribute to the understanding of the neurobiological bases of nicotine dependence.

Neuropeptide CART prevents memory loss attributed to withdrawal of nicotine following chronic treatment in mice

Although chronic nicotine administration does not affect memory, its withdrawal causes massive cognitive deficits. The underlying mechanisms, however, have not been understood. We test the role of cocaine- and amphetamine-regulated transcript peptide (CART), a neuropeptide known for its procognitive properties, in this process. The mice on chronic nicotine treatment/withdrawal were subjected to novel object recognition task. The capability of the animal to discriminate between the novel and familiar objects was tested and represented as discrimination index (DI); reduction in the index suggested amnesia. Nicotine for 49 days had no effect on DI, but 8-hour withdrawal caused a significant reduction, followed by full recovery at 24-hour withdrawal timepoint. Bilateral CART infusion in dorsal hippocampus rescued deficits in DI at 8-hours, whereas CART-antibody infusion into the dorsal hippocampus attenuated the recovery at 24-hours. Commensurate changes were observed in the CART as well as CART mRNA profiles in the hippocampus. CART mRNA expression and the peptide immunoreactivity did not change significantly following chronic nicotine treatment. However, there was a significant reduction at 8-hour withdrawal, followed by a drastic increase in CART immunoreactivity as well as CART mRNA at 24-hour withdrawal, compared with 8-hour withdrawal. Distinct α7-nicotinic receptor immunoreactivity was detected on the hippocampal CART neurons, suggesting cholinergic inputs. An increase in the synaptophysin immunoreactive elements around CART cells in the dentate gyrus, cornu ammonis 3 and subiculum at 24-hour post-withdrawal timepoint suggested neuronal plasticity. CART circuit dynamics in the hippocampus seems to modulate short-term memory associated with nicotine withdrawal.

Effects of nicotine and stress exposure across generations in C57BL/6 mice

Chronic administration of nicotine or exposure to stress can produce long-lasting behavioral and physiological changes in humans and animals alike. Further, the impact of nicotine and stress exposure can be inherited by offspring to produce persistent changes in physiology and behavior. To determine if nicotine and stress interact across generations to influence offspring behavior we exposed F0 male mice to nicotine and F1 male and female mice to chronic unpredictable stress during adolescence. We then measured locomotor sensitization to repeated nicotine injections in the subsequent F2 and F3 generations. Stress exposure alone (F1) did not influence locomotor sensitization in any lineage. However, in the F1 male lineage, F0 nicotine exposure abrogated locomotor sensitization in F2 male and transiently enhanced locomotor sensitization in F2 female offspring. These effects were not passed down to the F3 generations or observed in the F1 female lineage. F1 stress exposure modulated the effects of prior F0 nicotine exposure in a sex-dependent manner. Specifically, stress blunted the nicotine-induced enhancement in locomotor sensitization observed in F2 female offspring of F1 males. The effect of F0 nicotine and F1 stress exposure in females appears to have skipped a generation and enhanced nicotine sensitization only in the F3 generation, and only in females. This novel multigenerational exposure paradigm examining the inheritance of two different environmental exposures demonstrates that nicotine responses can be modified by nicotine and stress exposure from previous generations, and these effects are strongly influenced by sex.

Prevalence of periodontal status among nicotine dependent individuals of 35-44 years attending community dental camps in Ghaziabad district, Uttar Pradesh

Background:

Tobacco is the second driving reasons for mortality worldwide and its broad utilization in the smoking and smokeless form have added to the expanding weight of non-communicable disease.

Aim:

To study the prevalence of periodontal status among nicotine dependent individuals of 35-44 years attending community dental camps in Ghaziabad District, Uttar Pradesh.

Methods:

A cross-sectional study was conducted on 800 individuals with the age range of 35-44 years. A pre-tested questionnaire was used to gather information about the sociodemographic profile and the pattern of substance use. Fagerstrom Test for Nicotine Dependence-Smokeless Tobacco (FTND-ST) and for smokers; Fagerstrom Test for Nicotine Dependence (FTND) for testing dependence. Periodontal status was assessed by Community Periodontal Index (Modified CPI WHO 2013) and loss of attachment (LOA). Statistical analysis was done by the Statistical Package for Social Sciences (SPSS) version 20.0.

Result:

The prevalence of periodontal disease was found to be 78.5% with maximum disease prevalence among males of 42-44 age. Majority of male consumed a smokeless form of tobacco (50.23%), followed by smoke (14.19%) form whereas females predominantly consumed smokeless form (37.36%). The mean number of teeth with pocket (3.37 ± 1.86) and mean of loss of attachment of more than 9 mm (0.67 ± 0.88) was higher among smokeless form of tobacco users as compared to other habit groups

Conclusion:

Higher prevalence of periodontal disease was seen among nicotine dependent individuals. A model for a comprehensive program in the dental office including the five A's and five R's for tobacco counseling must be applied at every institute.

Impact of Substance Use Disorder Pharmacotherapy on Executive Function: A Narrative Review

Substance use disorders are chronic, relapsing, and harmful conditions characterized by executive dysfunction. While there are currently no approved pharmacotherapy options for stimulant and cannabis use disorders, there are several evidence-based options available to help reduce symptoms during detoxification and aid long-term cessation for those with tobacco, alcohol and opioid use disorders. While these medication options have shown clinical efficacy, less is known regarding their potential to enhance executive function. This narrative review aims to provide a brief overview of research that has investigated whether commonly used pharmacotherapies for these substance use disorders (nicotine, bupropion, varenicline, disulfiram, acamprosate, nalmefene, naltrexone, methadone, buprenorphine, and lofexidine) effect three core executive function components (working memory, inhibitory control and cognitive flexibility). While pharmacotherapy-induced enhancement of executive function may improve cessation outcomes in dependent populations, there are limited and inconsistent findings regarding the effects of these medications on executive function. We discuss possible reasons for the mixed findings and suggest some future avenues of work that may enhance the understanding of addiction pharmacotherapy and cognitive training interventions and lead to improved patient outcomes.

Zebrafish as an alternative method for determining the embryo toxicity of plant products: a systematic review

The toxicological assessment of plant products and pharmaceutical chemicals is a necessary requirement to ensure that all compounds are safe to be exposed to humans. Many countries are trying to reduce the use of animals; thus, alternative techniques, such as ex vivo tests, in vitro assays, and ex uteri embryos, are used. Toxicological assays using zebrafish embryos are an advantageous technique because they are transparent, have rapid embryonic development, and do not require invasive techniques. This paper comprehensively reviews how toxicity testing with plant products is conducted in zebrafish embryos. The search terms zebra fish, Danio rerio, zebrafish, zebra danio, Brachydanio rerio, zebrafish, and embryos were used to search for English-language articles in PUBMED, SCOPUS, and WEB OF SCIENCE. Twelve articles on plant product toxicity studies using zebrafish were selected for reading and analysis. After analyzing the articles and comparing with results in mammals, it was possible to prove the similarity among the results and thus corroborate the further development of zebrafish as a valid tool in toxicity tests.

Managing nicotine without smoke to save lives now: Evidence for harm minimization

Tobacco control has made strides in prevention and cessation, but deaths will not decline rapidly without massive behavior change. Currently, inhaled smoke from combusting tobacco is chiefly responsible for prematurely killing 7.2 million people worldwide and 530,000 in the United States annually. An array of noncombustible nicotine products (NNPs) has emerged and has disrupted the marketplace. Saving lives more speedily will require societal acceptance of locating a "sweet spot" within a three-dimensional framework where NNPs are simultaneously: 1. Less toxic, 2. Appealing (can reach smokers at scale), and 3. Satisfying (adequate nicotine delivery) to displace smoking. For this harm minimization framework to eliminate smoking, a laser focus on "smoking control" (not general tobacco control) is needed. By adopting these economically viable NNPs as part of the solution, NNPs can be smoking control's valued ally. Synthesis of the science indicates that policy and regulation can sufficiently protect youth while speeding the switch away from smoking. Despite some risks of nicotine dependence that can be mitigated but not eliminated, no credible evidence counters the assertion that NNPs will save lives if they displace smoking. But scientific evidence and advocacy has selectively exaggerated NNP harms over benefits. Accurate communication is crucial to dispel the misperception of NNPs harms and reassure smokers they can successfully replace smoking cigarettes with NNPs. Saving more lives now is an attainable and pragmatic way to call for alignment of all stakeholders and factions within traditional tobacco control rather than perpetuate the unrealized and unrealizable perfection of nicotine prohibition.

Observer-rated retardation but not agitation corresponds to objective motor measures in depression

OBJECTIVE

To explore the correlations between observer ratings and instrumental parameters across domains of psychomotor functioning in depression.

METHOD

In total, 73 patients with major depressive disorder underwent extensive psychomotor and clinical testing. Psychomotor functioning was assessed with (i) an observer-rated scale (the CORE measure) and also objectively with (ii) 24-h actigraphy, and (iii) a fine motor drawing task.

RESULTS

Observer ratings of retardation correlated with instrumental assessments of fine and gross motor functioning. In contrast, observer ratings of agitation did not correlate with observer ratings of retardation or with the instrumental measures. These associations were partly influenced by age and, to a lesser extent, by depression severity.

CONCLUSION

Psychomotor disturbance is a complex concept with different manifestations in depressed patients. Although observer ratings of retardation correspond well with instrumental measures of the motor domains, objective measurement of agitation and other aspects of psychomotor disturbance require further research.

Nicotine: Sporting Friend or Foe? A Review of Athlete Use, Performance Consequences and Other Considerations

Nicotine use amongst athletes is high and increasing, especially in team sports. This narrative review examines the rationale behind its use and evidence of its effect on physical performance, and considers important factors that should determine future research efforts. To date, ten studies have assessed muscular strength and power, sub- or maximal endurance and high-intensity exercise when nicotine (medication) or smokeless tobacco was used as an intervention. Two studies observed an ergogenic effect, one an ergolytic with the remaining seven reporting no change. These studies have notable limitations and confounding factors that include participant tolerance to nicotine, interindividual responses, the nicotine delivery system used and failure to adhere to rigorous experimental/scientific design. Further research is encouraged to address these limitations and determine the extent to which anti-doping and governing bodies should consider promoting, coordinating and monitoring any effort against nicotine and nicotine-containing substances in sports.

A cognitive model-based approach to testing mechanistic explanations for neuropsychological decrements during tobacco abstinence

RATIONALE

Cigarette smokers often experience cognitive decrements during abstinence from tobacco, and these decrements may have clinical relevance in the context of smoking cessation interventions. However, limitations of the behavioral summary statistics used to measure cognitive effects of abstinence, response times (RT) and accuracy rates, may restrict the field's ability to identify robust abstinence effects on task performance and test mechanistic hypotheses about the etiology of these cognitive changes.

OBJECTIVES

The current study explored whether a measurement approach based on mathematical models of cognition, which make the cognitive mechanisms necessary to perform choice RT tasks explicit, would be able to address these limitations.

METHODS

The linear ballistic accumulator model (LBA: Brown and Heathcote, Cogn Psychol 57(3):153-178, 2008) was fit to an existing data set from a study that evaluated the impact of overnight abstinence on flanker task performance.

RESULTS

The model-based analysis provided evidence that smokers' rates of mind wandering increased during abstinence, and was able to index this effect while controlling for participants' strategy changes that were related to the specific experimental paradigm used.

CONCLUSION

Mind wandering is a putative explanation for cognitive withdrawal symptoms during smoking cessation and may be indexed using the LBA. More broadly, the use of formal model-based analyses in future research on this topic has the potential to allow for strong and specific tests of mechanistic explanations for these symptoms.

Nicotine improves probabilistic reward learning in wildtype but not alpha7 nAChR null mutants, yet alpha7 nAChR agonists do not improve probabilistic learning

Cognitive impairments, e.g., reward learning, are present in various psychiatric disorders and warrant treatment. Improving reward-related learning could synergistically enhance psychosocial treatments and cognition generally. A critical first step is to understand the mechanisms underlying reward learning. The dopamine system has been implicated in such learning, but less known is how indirect activation of this system may affect reward learning. We determined the role of alpha7 nicotinic acetylcholine receptors (nAChR) on a probabilistic reversal learning task (PRLT) in mice that includes reward and punishment. Male alpha7 knockout (KO), heterozygous (HT), and wildtype (WT) littermate mice (n = 84) were treated with vehicle, 0.03, or 0.3 mg/kg nicotine. Two cohorts of C57BL/6NJ male mice were treated with various alpha7 nAChR ligands, including the full agonists PNU282877 and AR-R-17779, the positive allosteric modulator CCMI, the partial agonist SSR180711, and the antagonist methyllycaconitine. All mice were then tested in the PRLT. Nicotine (0.3 mg/kg) significantly improved initial reward learning in alpha7 WT and HT mice but did not improve learning in KO mice, suggesting an involvement of the alpha7 nAChR in the pro-learning effects of nicotine. Neither alpha7 nAChR treatments (PNU282987, AR-R-17779, CCMI, SSR180711, nor methyllycaconitine) affected mouse PRLT performance however. Nicotine improved reward learning via a mechanism that may include alpha7 nAChRs. This improvement unlikely relied solely on alpha7 nAChRs however, since no alpha7 nAChR ligand improved reward learning in normal mice. Future assessments of the effects of other nAChR subtypes on reward learning are needed.

Nicotine modulates human brain plasticity via calcium-dependent mechanisms

KEY POINTS

Nicotine (NIC) modulates cognition and memory function by targeting the nicotinic ACh receptor and releasing different transmitter systems postsynaptically. With both NIC-generated mechanisms, calcium influx and calcium permeability can be regulated, which is a key requirement for the induction of long-term potentiation, comprising the physiological basis of learning and memory function. We attempt to unmask the underlying mechanism of nicotinic effects on anodal transcranial direct current stimulation (tDCS)-induced long-term potentiation-like plasticity based on the hypothesis of calcium-dependency. Abolished tDCS-induced neuroplasticity as a result of NIC administration is reversed by calcium channel blockade with flunarizine in a dose-dependent manner. The results of the present study suggest that there is a dose determination of NIC/NIC agonists in therapeutical settings when treating cognitive dysfunction, which partially explains the heterogeneous results on cognition observed in subjects in different experimental settings.

ABSTRACT

Nicotine (NIC) modulates neuroplasticity and improves cognitive performance in animals and humans mainly by increased calcium permeability and modulation of diverse transmitter systems. NIC administration impairs calcium-dependent plasticity induced by non-invasive brain stimulation with transcranial direct current stimulation (tDCS) in non-smoking participants probably as a result of intracellular calcium overflow. To test this hypothesis, we analysed the effect of calcium channel blockade with flunarizine (FLU) on anodal tDCS-induced cortical excitability changes in healthy non-smokers under NIC. We applied anodal tDCS combined with NIC patch and FLU at three different doses (2.5, 5 and 10 mg) or with placebo medication. NIC abolished anodal tDCS-induced neuroplasticity. Under medium dosage (but not under low and high dosage) of FLU combined with NIC, plasticity was re-established. For FLU alone, the lowest dosage weakened long-term potentiation (LTP)-like plasticity, whereas the highest dosage again abolished tDCS-induced plasticity. The medium dosage turned LTP-like plasticity in long-term depression-like plasticity. The results of the present study suggest a key role of calcium influx and calcium levels in nicotinic effects on LTP-like plasticity in humans. This knowledge might be relevant for the development of new therapeutic strategies in cognitive dysfunction.

An integrated brain-behavior model for working memory

Working memory (WM) is a central construct in cognitive neuroscience because it comprises mechanisms of active information maintenance and cognitive control that underpin most complex cognitive behavior. Individual variation in WM has been associated with multiple behavioral and health features including demographic characteristics, cognitive and physical traits and lifestyle choices. In this context, we used sparse canonical correlation analyses (sCCAs) to determine the covariation between brain imaging metrics of WM-network activation and connectivity and nonimaging measures relating to sensorimotor processing, affective and nonaffective cognition, mental health and personality, physical health and lifestyle choices derived from 823 healthy participants derived from the Human Connectome Project. We conducted sCCAs at two levels: a global level, testing the overall association between the entire imaging and behavioral-health data sets; and a modular level, testing associations between subsets of the two data sets. The behavioral-health and neuroimaging data sets showed significant interdependency. Variables with positive correlation to the neuroimaging variate represented higher physical endurance and fluid intelligence as well as better function in multiple higher-order cognitive domains. Negatively correlated variables represented indicators of suboptimal cardiovascular and metabolic control and lifestyle choices such as alcohol and nicotine use. These results underscore the importance of accounting for behavioral-health factors in neuroimaging studies of WM and provide a neuroscience-informed framework for personalized and public health interventions to promote and maintain the integrity of the WM network.

Smoking does not impact social and non-social cognition in patients with first episode psychosis

BACKGROUND

Many studies having shown significant improvements in non-social and social cognitive performance in smoking FEP patients compared to non-smoking FEP patients. The findings are controversial. This study analyzed the effects of tobacco use on non-social and social cognitive function in a large group of FEP patients and a matched healthy control group.

METHODS

A sample of 335 patients with FEP and 253 healthy controls was divided into four subgroups: control tobacco users (CTU), control non-tobacco users (CNTU), patient tobacco users (PTU) and patient non-tobacco users (PNTU). Demographic variables, tobacco use variables (presence or absence, frequency and duration of tobacco use), neurocognitive (non-social) performance and social cognition were assessed.

RESULTS

Comparison of 4 subgroups in non-social cognitive function revealed significant differences after controlling for covariables in executive functions (F=13.45; p≤0.001) and working memory domains (F=4.30; p=0.005). CTU and CNTU subgroups scored higher in all the domains compared to the PTU and the PNTU subgroups respectively. Social cognitive function was also significantly different within the four subgroups, with control subgroups showing better social cognition than patient subgroups. Significant differences in the executive functions domain were observed when comparing PTU and CTU groups (F=19.60; p≤0.001). No significant differences were revealed in the comparison between the patient groups.

CONCLUSIONS

This large study suggests that tobacco use in FEP patients is not related to better non-social or social cognitive performance.

Pharmaceutical cognitive doping in students: A chimeric way to get-a-head?

For students, the pressing demands for memorization, top-level performance, and peer competition create an environment favorable for pharmaceutical cognitive doping behavior. We aimed to describe recent practices and the benefit/risk ratio of such behavior and to discuss the issues at stake. The prevalence of pharmaceutical cognitive doping among students has been reported from 1.3% to 33% across studies, with variations depending on country and definition of pharmaceutical cognitive doping. The therapeutic classes most frequently cited as being diverted for doping purposes are psychostimulants and nootropics (methylphenidate, modafinil, piracetam), corticosteroids, sedative drugs and beta-blockers. Some illegal substances such as cannabis, amphetamines and cocaine are also consumed in order to boost mental function. Finally, over-the-counter products, such as caffeine-based tablets or energy drinks, or alcohol, are also widely used by students whose motivations involve enhanced performance, concentration, memory, and staying awake during the revision and exam period. However, the expected (often fantasized) effectiveness of these products does not correspond to the reality of a modest controversial impact on cognitive performance. There appears to be an emerging profile of the student more inclined to doping behavior. Cognitive doping thus raises the question of its regulation, opening a debate opposing, on one hand, individual freedom and supposed collective benefits and, on the other hand, health consequences, educational (in)equality, and the risk of tarnished academic success. Strengthening school and university medicine, through prevention campaigns and the identification of subjects at risk, is essential to limit the extent, risk, and damages associated with such practices.

Transdermal Nicotine for the Treatment of Mood and Cognitive Symptoms in Nonsmokers With Late-Life Depression

OBJECTIVE

Late-life depression (LLD) is characterized by poor antidepressant response and cognitive dysfunction. This study examined whether transdermal nicotine benefits mood symptoms and cognitive performance in LLD.

METHODS

In a 12-week open-label outpatient study conducted between November 2016 and August 2017, transdermal nicotine was given to 15 nonsmoking older adults (≥ 60 years of age). Eligible participants met DSM-IV-TR criteria for major depressive disorder with ≥ 15 on the Montgomery-Asberg Depression Rating scale (MADRS) and endorsed subjective cognitive impairment. Transdermal nicotine patches were applied daily and titrated in a rigid dose escalation strategy to a maximum dose of 21.0 mg/d, allowing dose reductions for tolerability. The primary mood outcome was MADRS change measured every 3 weeks, with response defined as ≥ 50% improvement from baseline and remission as MADRS score ≤ 8. The primary cognitive outcome was the Conners Continuous Performance Test (CPT), a test of attention.

RESULTS

Robust rates of response (86.7%; 13/15 subjects) and remission (53.3%; 8/15 subjects) were observed. There was a significant decrease in MADRS scores over the study (β = -1.51, P < .001), with improvement seen as early as 3 weeks (Bonferroni-adjusted P value = .004). We also observed improvement in apathy and rumination. We did not observe improvement on the CPT but did observe improvement in subjective cognitive performance and signals of potential drug effects on secondary cognitive measures of working memory, episodic memory, and self-referential emotional processing. Overall, transdermal nicotine was well tolerated, although 6 participants could not reach the maximum targeted dose.

CONCLUSIONS

Nicotine may be a promising therapy for depressed mood and cognitive performance in LLD. A definitive placebo-controlled trial and establishment of longer-term safety are necessary before clinical usage.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT02816138​.

Phase IIb Trial of an α7 Nicotinic Receptor Partial Agonist With and Without Nicotine Patch for Withdrawal-Associated Cognitive Deficits and Tobacco Abstinence

PURPOSE/BACKGROUND

The objective of this study was to determine whether a novel α7 nicotinic acetylcholine receptor partial agonist improves cognition during nicotine withdrawal and improves abstinence rates. To do so, the effect of the α7 nicotinic acetylcholine receptor partial agonist, encenicline, on cognition and abstinence was evaluated when given as monotherapy and when combined with transdermal nicotine patch (nicotine replacement therapy [NRT]).

METHODS

Adult daily smokers, n = 160, who were motivated to quit smoking completed cognitive testing at satiated baseline and after overnight abstinence and then were randomized to receive a 12-week trial of encenicline 1 mg twice daily or identical placebo the day of the overnight abstinent cognitive testing. In the first 6 weeks of the 12-week encenicline administration, participants were also randomized to 6 weeks of NRT patch or placebo patch. Primary outcomes were cognition during abstinence and 7-day point-prevalence abstinence at week 12.

RESULTS

No beneficial effects of encenicline were observed on cognition or abstinence when compared with placebo or when combined with NRT compared with placebo capsule + NRT. Of the 4 conditions, abstinence rates were lowest among those assigned to encenicline alone.

CONCLUSIONS

Beneficial effects of NRT were observed on cognitive and abstinence outcomes when combined with encenicline compared with encenicline plus placebo patch. Addition of NRT to encenicline improved odds of abstinence approximately 3-fold compared with encenicline plus placebo patch. We conclude that encenicline, 1 mg/d, did not improve abstinence-associated cognitive impairment or abstinence rates as monotherapy or adjunctive therapy to NRT patch.

Prevention of progression in Parkinson's disease

Environmental influences affecting genetically susceptible individuals seem to contribute significantly to the development of Parkinson’s disease (PD). Xenobiotic exposure including transitional metal deposition into vulnerable CNS regions appears to interact with PD genes. Such exposure together with mitochondrial dysfunction evokes a destructive cascade of biochemical events, including oxidative stress and degeneration of the sensitive dopamine (DA) production system in the basal ganglia. Recent research indicates that the substantia nigra degeneration can be decelerated by treatment with iron binding compounds such as deferiprone. Interestingly compounds known to decrease PD risk including caffeine, niacin, nicotine and salbutamol also possess iron binding properties. Adequate function of antioxidative mechanisms in the vulnerable brain cells can be restored by acetylcysteine supplementation to normalize intracellular glutathione activity. Other preventive measures to reduce deterioration of dopaminergic neurons may involve life-style changes such as intake of natural antioxidants and physical exercise. Further research is recommended to identify therapeutic targets of the proposed interventions, in particular protection of the DA biosynthesis by oxygen radical scavengers and iron binding agents.

Factors that positively or negatively mediate the effects of age on working memory across the adult life span

Working memory abilities significantly decrease with advancing age; hence, the search for factors that may increase or mitigate this decline is critical. Several factors have been identified that influence working memory; however, their effects have been mainly assessed separately and rarely together with other factors in the same sample. We examined 120 variables to search for factors that jointly act as mediators of working memory decay across the adult life span. A sample of 1652 healthy adults was assessed in spatial and verbal working memory domains. Structural equation modeling analyses were conducted to search for potential mediators that intervened between age and working memory. Only 14 and 10 variables reliably mediated spatial and verbal working memory, respectively. Factors from several domains remained in the models, such as individual characteristics, physiological traits, consumption habits, and regular activities. These factors are sufficiently powerful to influence working memory decline when they jointly interact, as in everyday living.

Effects of task repetition but no transfer of inhibitory control training in healthy adults

Executive functions (EFs) comprise the updating, shifting and inhibition dimensions. According to the Unity and Diversity Model, the inhibition dimension is fully accounted for by a general EFs factor. This suggests that training of inhibition should transfer, in part, to updating and shifting. Therefore, we tested the effectiveness of a three-week inhibition training (high-conflict Stroop task) and explored near transfer effects to an untrained inhibition task (antisaccade task) and far transfer effects to untrained tasks demanding task-set shifting (number-letter-task), working memory updating (n-back task) and planning abilities (Stockings of Cambridge task). We employed a randomized pretest/treatment/posttest study design in n = 102 healthy young adults, assigned to an intensive Stroop training (n = 38), an active control condition (n = 34) or no training intervention (n = 30). In the Stroop training group, Stroop performance improved with practice, while performance in the active control group remained unchanged. The Stroop training group showed improvements in overall Stroop task performance from pretest to posttest, but we observed neither near nor far transfer effects. Additionally, specifically stronger gains on incongruent Stroop trials compared to congruent trials were observed in the Stroop training group when color bar trials were excluded from the pretest-posttest-analysis. Generally, there were substantial improvements from pretest to posttest independent of training condition in all transfer tasks. In sum, our data do not support the existence of transfer effects from inhibition training in healthy young adults.

Nicotinic Restoration of Excitatory Neuroplasticity Is Linked to Improved Implicit Motor Learning Skills in Deprived Smokers

Nicotine has been shown to modulate neuroplasticity, cognition, and learning processes in smokers and non-smokers. A possible mechanism for its effect on learning and memory formation is its impact on long-term depression and long-term potentiation (LTP). Nicotine abstinence in smokers is often correlated with impaired cognitive performance. As neuroplasticity is closely connected to learning and memory formation, we aimed to explore the effect of nicotine spray administration in deprived smokers on paired-associative stimulation (PAS25)-induced neuroplasticity and on performance of the serial reaction time task (SRTT), a sequential motor learning paradigm. Deprived smokers (n = 12) under placebo medication displayed reduced excitatory neuroplasticity induced by PAS25. Plasticity was restored by nicotine spray administration. Likewise, SRTT-performance improved after nicotine spray administration compared to placebo administration (n = 19). The results indicate a restitutional effect of nicotine spray in deprived smokers on both: LTP-like neuroplasticity and motor learning. These results present a possible explanation for persistence of nicotine addiction and probability of relapse.

Schizophrenia: synthetic strategies and recent advances in drug design

Schizophrenia is a complex and unpredictable mental disorder which affects several domains of cognition and behaviour. It is a heterogeneous illness characterised by positive, negative, and cognitive symptoms, often accompanied by signs of depression. In this tutorial review, we discuss recent progress in understanding the target sites and mechanisms of action of second-generation antipsychotic drugs. Progress in identifying and defining target sites has been accelerated recently by advances in neuroscience, and newly developed agents that regulate signalling by the main excitatory neurotransmitters in the brain are surveyed. Examples of novel molecules for the treatment of schizophrenia in preclinical and clinical development and their industrial sponsors are highlighted.

Trace Amine-Associated Receptor 1 Modulates the Locomotor and Sensitization Effects of Nicotine

Trace amine-associated receptor 1 (TAAR1) has emerged as a promising target for addiction treatments because it affects dopamine transmission in the mesolimbic pathway. TAAR1 is involved in the effects of addictive drugs, such as amphetamines, cocaine and ethanol, but the impact of TAAR1 on the effects of nicotine, the psychoactive drug responsible for the development and maintenance of tobacco smoking, has not yet been studied. This study was performed to investigate the possible modulatory action of TAAR1 on the effects of nicotine on locomotor behaviors in rats and mice. Pretreatment with the TAAR1 agonist RO5263397 dose-dependently decreased nicotine-induced hyperlocomotion in rats habituated to locomotor boxes, prevented the development of nicotine sensitization and blocked hypermotility in nicotine-sensitized rats at the highest tested dose (10 mg/kg). The lack of TAAR1 failed to affect the effects of nicotine on the locomotion of mutant mice. Based on the results of the present study, TAAR1 activation attenuates the locomotion-stimulating effects of nicotine on rats. These results further support the previously proposed hypothesis that TAAR1 is a promising target for the prevention and treatment of drug addiction. Further studies aimed at analyzing the effects of TAAR1 agonists on animal models of nicotine addiction are warranted.

Features and outcomes of drugs for combination therapy as multi-targets strategy to combat Alzheimer's disease

ETHNOPHARMACOLOGICAL RELEVANCE

Alzheimer's disease (AD), a deleterious neurodegenerative disorder that impairs memory, cognitive functions and may lead to dementia in late stage of life. The pathogenic cause of AD remains incompletely understood and FDA approved drugs are partial inhibitors rather than curative. Most of drugs are synthetic or natural products as galanthamine is an alkaloid obtained from Galanthus spp. Huperzine A, an alkaloid found in Huperzia spp., gingkolides a diterpenoids from Gingko biloba and many ethnobotanicals like Withania somnifera (L.) Dunal., Physostigma venenosum Balf., Bacopa monnieri (L.) Wettst., Centella asiatica (L.) Urb. have been used by traditional Indian, Chinese, and European system of medicines in AD. Clinical significance opioid alkaloid in Papaver somniferum has shown another dimension to this study. Over exploitation of medicinal plants with limited bioactive principles has provided templates to design synthetic drugs in AD e.g. rivastigmine, phenserine, eptastigmine based on chemical structure of physostigmine of Physostigma venenosum Balf. Even ZT-1 a prodrug of Hup A and memogain a prodrug of galantamine has achieved new direction in drug development in AD. All these first-line cholinesterase-inhibitors are used as symptomatic treatments in AD. Single modality of "One-molecule-one-target" strategy for treating AD has failed and so future therapies on "Combination-drugs-multi-targets" strategy (CDMT) will need to address multiple aspects to block the progression of pathogenesis of AD. Besides, cholinergic and amyloid drugs, in this article we summarize proteinopathy-based drugs as AD therapeutics from a variety of biological sources. In this review, an attempt has been made to elucidate the molecular mode of action of various plant products, and synthetic drugs investigated in various preclinical and clinical tests in AD. It also discusses current attempts to formulate a comprehensive CDMT strategy to counter complex pathogenesis in AD.

MATERIALS AND METHODS

Information were collected from classical books on medicinal plants, pharmacopoeias and scientific databases like PubMed, Scopus, GoogleScholar, Web of Science and electronic searches were performed using Cochrane Library, Medline and EMBASE. Also published scientific literatures from Elsevier, Taylor and Francis, Springer, ACS, Wiley publishers and reports by government bodies and documentations were assessed.

RESULTS

60 no. of natural and synthetic drugs have been studied with their significant bioactivities. A decision matrix designed for evaluation of drugs for considering to the hypothetic "CDMT" strategy in AD. We have introduced the scoring pattern of individual drugs and based on scoring pattern, drugs that fall within the scoring range of 18-25 are considered in the proposed CDMT. It also highlights the importance of available natural products and in future those drugs may be considered in CDMT along with the qualified synthetic drugs.

CONCLUSION

A successful validation of the CDMT strategy may open up a debate on health care reform to explore other possibilities of combination therapy. In doing so, it should focus on clinical and molecular relationships between AD and CDMT. A better understanding of these relationships could inform and impact future development of AD-directed treatment strategies. This strategy also involves in reducing costs in treatment phases which will be affordable to a common man suffering from AD.

Addiction Vulnerability: Exploring Relationships Among Cigarette Smoking, Substance Misuse, and Early Psychosis

OBJECTIVE

Smoking rates in adolescents at risk for psychosis are significantly greater than in those who are not at risk. Recent research suggests that cigarette smoking in adolescence may be a potential marker of transition to psychosis, although the exact relationship between the two remains unclear. Our aim was to examine whether tobacco smoking is a potential marker of transition to psychosis or subsequent episodes of psychosis, independently of other substance use, or alternatively whether smoking is essentially a general marker of later mental illness episodes.

METHODS

This substudy was conducted as part of an audit of a specialized early psychosis community mental health service, the Psychological Assistance Service (PAS). A multilayered audit over 10 years (January 1997 to December 2007) of PAS presentations was conducted (N = 1997), which documented baseline sociodemographic and clinical characteristics and subsequent illness episodes and service usage. Among clients with baseline smoking status information (n = 421, mean age = 18.3 years), this study examined predictors of transition to or subsequent episodes of psychosis, substance misuse, and affective disorder.

RESULTS

A recent psychosis episode at baseline and receiving ongoing treatment from PAS predicted transition to or subsequent psychosis episodes; however, baseline ultra-high-risk status was not predictive. In addition, baseline smoking/substance misuse status was a significant predictor, with smokers being twice as likely to experience a subsequent episode of psychosis, even after controlling for other baseline comorbidity. Baseline smoking status also independently predicted subsequent substance misuse episodes, but not subsequent affective disorder. Among clients experiencing post-PAS comorbid substance misuse and psychosis, the majority (80.3%) reported smoking at baseline.

CONCLUSIONS

Smoking status at service presentation appeared to function as a general proxy for addiction vulnerability among young help seekers and thereby as a potential marker for the development of severe mental illness (including psychosis) and associated health problems. Routine evaluations of presenting problems need to incorporate comprehensive assessments of early substance misuse and tobacco smoking. Adjunctive lifestyle interventions promoting smoking cessation, physical health, and well-being need to be offered in conjunction with conventional mental health interventions tailored to key presenting problems, recovery, and psychological strengthening.

Harm Minimization and Tobacco Control: Reframing Societal Views of Nicotine Use to Rapidly Save Lives

Inhalation of the toxic smoke produced by combusting tobacco products, primarily cigarettes, is the overwhelming cause of tobacco-related disease and death in the United States and globally. A diverse class of alternative nicotine delivery systems (ANDS) has recently been developed that do not combust tobacco and are substantially less harmful than cigarettes. ANDS have the potential to disrupt the 120-year dominance of the cigarette and challenge the field on how the tobacco pandemic could be reversed if nicotine is decoupled from lethal inhaled smoke. ANDS may provide a means to compete with, and even replace, combusted cigarette use, saving more lives more rapidly than previously possible. On the basis of the scientific evidence on ANDS, we explore benefits and harms to public health to guide practice, policy, and regulation. A reframing of societal nicotine use through the lens of harm minimization is an extraordinary opportunity to enhance the impact of tobacco control efforts.

Minimal effects of prolonged smoking abstinence or resumption on cognitive performance challenge the "self-medication" hypothesis in schizophrenia

One prominent, long-standing view is that individuals with schizophrenia smoke cigarettes more than the general population to "self-medicate" cognitive deficits and other symptoms. This study tested the self-medication hypothesis by examining the effects of smoking abstinence and resumption on cognition in patients with schizophrenia. Nicotine-dependent smokers with schizophrenia (n=26) were trained on a cognitive battery and then hospitalized to achieve and maintain confirmed abstinence from smoking for ~1 week. Cognition was tested while smoking as usual (baseline), one day after smoking cessation (early abstinence), ~1 week later (extended abstinence), and within ~3 weeks of resuming smoking (resumption). The test battery included measures of processing speed, attention, conflict resolution, verbal memory, working memory, verbal fluency, and executive function to evaluate multiple cognitive domains affected by schizophrenia. Positive and negative symptoms of schizophrenia, depressive symptoms, and dyskinesia were also measured at baseline and after prolonged abstinence. There were no significant changes in global cognitive test performance with smoking cessation, abstinence, or resumption. There were small decreases in a measure of processing speed and delayed verbal recall with abstinence, but these findings failed to survive adjustments for multiple comparisons. Surprisingly, in this within subject "On-Off-Off-On" design, there were no significant effects of early or prolonged abstinence from smoking on cognitive and behavioral measures in smokers with schizophrenia. The results of this study challenge the widely held "self-medication" hypothesis of smoking and schizophrenia, question the extent of pro-cognitive effects of smoking and nicotine in schizophrenia, and support encouraging smoking cessation in schizophrenia.

N-Oleoyl-glycine reduces nicotine reward and withdrawal in mice

Cigarette smokers with brain damage involving the insular cortex display cessation of tobacco smoking, suggesting that this region may contribute to nicotine addiction. In the present study, we speculated that molecules in the insular cortex that are sensitive to experimental traumatic brain injury (TBI) in mice might provide leads to ameliorate nicotine addiction. Using targeted lipidomics, we found that TBI elicited substantial increases of a largely uncharacterized lipid, N-acyl-glycine, N-oleoyl-glycine (OlGly), in the insular cortex of mice. We then evaluated whether intraperitoneal administration of OlGly would alter withdrawal responses in nicotine-dependent mice as well as the rewarding effects of nicotine, as assessed in the conditioned place preference paradigm (CPP). Systemic administration of OlGly reduced mecamylamine-precipitated withdrawal responses in nicotine-dependent mice and prevented nicotine CPP. However, OlGly did not affect morphine CPP, demonstrating a degree of selectivity. Our respective in vitro and in vivo observations that OlGly activated peroxisome proliferator-activated receptor alpha (PPAR-α) and the PPAR-α antagonist GW6471 prevented the OlGly-induced reduction of nicotine CPP in mice suggests that this lipid acts as a functional PPAR-α agonist to attenuate nicotine reward. These findings raise the possibility that the long chain fatty acid amide OlGly may possess efficacy in treating nicotine addiction.

A Preliminary Investigation on Smokeless Tobacco Use and Its Cognitive Effects Among Athletes

Introduction: Among athletes, an increasing use of nicotine via smokeless tobacco has been reported. However, there are currently unanswered questions about whether the use by athletes is due to nicotine’s addictive properties and/or to benefits in physical and cognitive performance (e.g., decision-making). In this original article we reported about, (i) snus-induced reinforcing effects among snus-user athletes (Survey) and (ii) the effects of snus on the Iowa Gambling Task (IGT) in snus-user skiers (Experimental study). IGT is an experimental neuropsychological task that has been previously used on athletes and addicts to test decision-making.

Methods: Survey: data were collected with the modified Cigarette Evaluation Questionnaire (mCEQ) that was administered to 61 winter sport athlete snus-users in Northern Italy. Experimental study: IGT data included: amount of money earned, number of choices from advantageous and disadvantageous decks and overall net score. Eighteen male snus-users were tested under satiety or after 12-h abstinence conditions according to a crossover design.

Results: Survey: the comparison between occasional vs. regular snus-users showed a statistically significant difference in satisfaction (P = 0.0088), calm (P = 0.0252), and enjoyment (P = 0.0001) mCEQ items suggesting a snus intake/effect relationship. Experimental study: significantly higher IGT net scores were found during the first 20 choice cards after abstinence vs. satiety conditions (P = 0.0024).

Conclusion: In the Survey, regular snus use induces greater satisfaction and psychological reward than occasional use. In the Experimental study, snus intake might produce an early and transient cognitive improvement on IGT in abstinent snus-users, presumably acting as a withdrawal relief.

Tobacco Use Decreases Visual Sensitivity in Schizophrenia

Smoking prevalence in patients who are diagnosed with schizophrenia (SCZ) is higher than in the general population. Chronic tobacco use in SCZ patients may reduce the side effects of antipsychotic drugs, thus serving as a self-medication for such side effects. Understanding the ways in which chronic tobacco use influences visual sensitivity has clinical implications, which may serve as a tool for non-invasively diagnosing early-stage visual processing deficits. The present study evaluated the effects of chronic tobacco use on visual sensitivity in SCZ patients. Our purpose was to provide new directions for future research, mainly psychophysical and electrophysiological studies. In the present study, 40 smoker controls (SC), 20 SCZ tobacco users, and 20 SCZ tobacco nonusers were recruited from the Psychosocial Care Center. Visual sensitivity was compared between both SCZ groups and the SC group. Patients with SCZ who were chronic tobacco users presented lower visual sensitivity for chromatic (p < 0.001) and achromatic (p < 0.001) stimuli compared with the other groups. Our findings highlight the need to evaluate possible addictive behavior in patients with SCZ, which may contribute to public policies that seek to improve the quality of life of SCZ patients and their families.

Learning and memory performance following acute intranasal insulin administration in abstinent smokers

The highest incidence of relapse to smoking occurs within the first 2 weeks of a cessation attempt. In addition to enhanced nicotine craving, this phase of smoking cessation is also marked by learning and memory dysfunction. Many smokers are not able to overcome these symptoms, and they relapse to smoking shortly after trying to quit. In two clinical studies, we evaluated intranasal insulin for efficacy in improving learning and memory function during nicotine withdrawal. Our first study was a crossover evaluation (N = 19) following 20 hr of smoking abstinence. Study 2 was a parallel design study (N = 50) following 16 hr of abstinence. Intranasal insulin (60 IU) dose was administered in both studies and cognitive function was measured using California Verbal Learning Test-II. Intranasal insulin did not improve learning over the 5 verbal learning trials. In addition, intranasal insulin did not improve either short- or long-delay recall in either study. In summary, the one-time administration of intranasal insulin does not improve verbal learning and memory in smokers. Whether longer administration schedules may be of benefit should be evaluated in future studies.

Cognitive effects of labeled addictolytic medications

INTRODUCTION

Alcohol, tobacco, and illegal drug usage is pervasive throughout the world, and abuse of these substances is a major contributor to the global disease burden. Many pharmacotherapies have been developed over the last 50years to target addictive disorders. While the efficacy of these pharmacotherapies is largely recognized, their cognitive impact is less known. However, all substance abuse disorders are known to promote cognitive disorders like executive dysfunction and memory impairment. These impairments are critical for the maintenance of addictive behaviors and impede cognitive behavioral therapies that are regularly administered in association with pharmacotherapies. It is also unknown if addictolytic medications have an impact on preexisting cognitive disorders, and if this impact is modulated by the indication of prescription, i.e. abstinence, reduction or substitution, or by the specific action of the medication.

METHOD

We reviewed the cognitive effects of labeled medications for tobacco addiction (varenicline, bupropion, nicotine patch and nicotine gums), alcohol addiction (naltrexone, nalmefene, baclofen, disulfiram, sodium oxybate, acamprosate), and opioid addiction (methadone, buprenorphine) in human studies. Studies were selected following MOOSE guidelines for systematic reviews of observational studies, using the keywords [Cognition] and [Cognitive disorders] and [treatment] for each medication.

RESULTS

971 articles were screened and 77 studies met the inclusion criteria and were reported in this review (for alcohol abuse, n=21, for tobacco n=22, for opioid n=34. However, very few comparative clinical trials have explored the chronic effects of addictolytic medications on cognition in addictive behaviors, and there are no clinical trials on the cognitive impact of nalmefene in patients suffering from alcohol use disorders.

DISCUSSION

Although some medications seem to enhance cognition in patients suffering from cognitive disorders, others could promote cognitive impairments, and our work highlights a lack of literature on this subject. In conclusion, more comparative clinical trials are needed to better understand the cognitive impact of addictolytic medications.

Tobacco smoking and its association with cognition in first episode psychosis patients

Available evidence suggests that nicotine may enhance cognitive functioning. Moreover, it has been suggested that the high prevalence of smoking in people with schizophrenia is in part due to self-medication behaviour to alleviate cognitive deficits. We assessed the association between tobacco smoking and cognitive functioning in a large population of first episode psychosis (FEP) patients (n=304) and healthy controls (n=156). Smokers were not tobacco deprived, or were minimally deprived (≤2h). Verbal memory, visual memory, working memory, processing speed, executive function, motor dexterity and attention were assessed. The smoking prevalence among the FEP group was 57% (n=174). The age at which patients began smoking cigarettes regularly was 16.2years (SD=3.1), an average of 12years before experiencing the first frank symptoms of psychosis (age of onset=28.8; SD=9.3). The number of cigarettes smoked per day was 19.6 (SD=9.4), significantly more than healthy controls [11.0 (SD=7.6); p<0.001]. ANCOVA analysis did not show any significant difference between smokers and non-smokers in in the performance of any of the cognitive tasks in the FEP group or in the healthy control group, independent of gender, age, education or premorbid IQ. This suggests chronic exposure to nicotine through cigarette smoking is not associated with cognitive functioning in first-episode psychosis. These findings do not support the nicotine self-medication hypothesis as a contributor to the high prevalence of smoking among individuals suffering from serious mental illness.

Associations Between Substance Use in Commission of Sexual Crimes and Offense Characteristics Among Youth: Mitigating Effects of Substance Use Treatment

The small extant research base on substance use and youth sexual offending has very few descriptive details. Furthermore, research has yet to test associations between the use of substances in the commission of sexual crimes and offense-related characteristics and how substance use treatment can mitigate these effects. In a sample of residentially housed youth adjudicated of a sexual crime ( N = 332), prevalence patterns are broken down by type of substance use behavior. Sequential regression models are run to test the associations between substance use prior to a sexual crime and number of victims, sexual deviance, and non-sexual criminality. Substance use treatment is tested as a mitigating factor in these relationships. Results reveal high levels of family substance use, and high rates of alcohol, marijuana, and other substance use. There were associations between substance use prior to sexual criminality and sexual deviance and non-sexual criminality. Substance use treatment reduced the effects of substance use on non-sexual criminality. Research and treatment implications are offered.

Cognitive Effects of Nicotine: Recent Progress

BACKGROUND

Cigarette smoking is the main cause of preventable death in developed countries. While the direct positive behavioral reinforcing effect of nicotine has historically been considered the primary mechanism driving the development of TUD, accumulating contemporary research suggests that the cognitive-enhancing effects of nicotine may also significantly contribute to the initiation and maintenance of TUD, especially in individuals with pre-existing cognitive deficits.

METHODS

We provide a selective overview of recent advances in understanding nicotine's effects on cognitive function, a discussion of the role of cognitive function in vulnerability to TUD, followed by an overview of the neurobiological mechanisms underlying the cognitive effects of nicotine.

RESULTS

Preclinical models and human studies have demonstrated that nicotine has cognitiveenhancing effects. Attention, working memory, fine motor skills and episodic memory functions are particularly sensitive to nicotine's effects. Recent studies have demonstrated that the α4, β2, and α7 subunits of the nicotinic acetylcholine receptor (nAChR) participate in the cognitive-enhancing effects of nicotine. Imaging studies have been instrumental in identifying brain regions where nicotine is active, and research on the dynamics of large-scale networks after activation by, or withdrawal from, nicotine hold promise for improved understanding of the complex actions of nicotine on human cognition.

CONCLUSION

Because poor cognitive performance at baseline predicts relapse among smokers who are attempting to quit smoking, studies examining the potential efficacy of cognitive-enhancement as strategy for the treatment of TUD may lead to the development of more efficacious interventions.