Cost-effectiveness of drug consumption rooms in France: a modelling study.

BACKGROUND: People who inject drugs (PWID) experience many health problems which result in a heavy economic and public health burden. To tackle this issue, France opened two drug consumption rooms (DCRs) in Paris and Strasbourg in 2016. This study assessed their long-term health benefits, costs and cost-effectiveness. METHODS: We developed a model to simulate two fictive cohorts for each city (n=2,997 in Paris and n=2,971 in Strasbourg) i) PWID attending a DCR over the period 2016-2026, ii) PWID attending no DCR. The model accounted for HIV and HCV infections, skin abscesses and related infective endocarditis, drug overdoses and emergency department visits. We estimated the number of health events and associated costs over 2016-2026, the lifetime number of quality-adjusted life-years (QALYs) and costs, and the incremental cost-effectiveness ratio (ICER). RESULTS: The numbers of abscesses and associated infective endocarditis, drug overdoses, and emergency department visits decreased significantly in PWID attending DCRs (-77%, -69%, and -65%, respectively) but the impact on HIV and HCV infections was modest (-11% and -6%, respectively). This resulted in savings of €6.6 (Paris) and €5.8 (Strasbourg) millions of medical costs. The ICER of DRCs was €30,600/QALY (Paris) and €9,200/QALY (Strasbourg). In scenario analysis where drug consumption spaces are implemented inside existing harm reduction structures, these ICERs decreased to €21,400/QALY and €2,500/QALY, respectively. CONCLUSIONS: Our findings show that DCRs are highly effective and efficient to prevent harms in PWID in France, and advocate extending this intervention to other cities by adding drug consumption spaces inside existing harm reduction centers.

Gender and Drug Use Discrimination Among People Who Inject Drugs: An Intersectional Approach Using the COSINUS Cohort.

Purpose: Injection drug use is strongly associated with stigmatization by loved ones, healthcare providers, and society in general. This stigmatization can have negative consequences on the health of people who inject drugs (PWID) and limit their access to care. Women who inject drugs face greater stigma than men because of gendered social norms and the intersectional effect between gender and drug use identities. For this analysis, we aimed to study discrimination - which is closely linked to stigmatization - experienced by PWID, considering the intersectionality between drug use discrimination and gender discrimination in the French context. Methods: We used data from the COSINUS cohort study, conducted between June 2016 and May 2019 in four French cities. We selected 427 of the 665 PWID who regularly injected drugs enrolled in COSINUS, at three months of follow-up, and performed multivariable logistic regression to identify factors associated with self-reported drug use discrimination. Results: Women comprised 20.6% of the study sample. Sixty-nine percent of the participants declared drug use discrimination and 15% gender discrimination. In the multivariable regression analysis, PWID who had hurried injection out of fear of being seen were almost twice as likely to have experienced drug use discrimination (OR [95% CI]: 1.77 [1.15, 2.74], p = 0.010). Likewise, women experiencing gender discrimination were almost three times as likely to have experienced drug use discrimination (OR [95% CI]: 2.84 [1.07,7.56], p=0.037). Conclusion: Women who inject drugs experienced gender and drug use intersectional discrimination. This could be a reason for the low attendance rates of women in healthcare settings. In addition, discrimination negatively impacted injection drug use practices (eg, hurried injection), particularly for people with unstable housing who injected in public spaces. We recommend introducing adapted services in healthcare facilities for women who inject drugs, and creating a favorable social and physical environment for all PWID in order to improve their health and access to care.

Drug consumption rooms are effective to reduce at-risk practices associated with HIV/HCV infections among people who inject drugs: Results from the COSINUS cohort study.

AIMS: The primary aim of this study was to evaluate the impact of drug consumption rooms (DCRs) in France on injection equipment-sharing, while the secondary aims focused upon their impact on access to hepatitis C virus (HCV) testing and opioid agonist treatment (OAT). DESIGN: The COhort to identify Structural and INdividual factors associated with drug USe (COSINUS cohort) was a 12-month longitudinal study of 665 people who inject drugs (PWID), conducted in Bordeaux, Marseille, Paris and Strasbourg. We used data from face-to-face interviews at enrolment and at 6-month and 12-month visits. SETTING AND PARTICIPANTS: The participants were recruited in harm reduction programmes in Bordeaux and Marseille and in DCRs in Strasbourg and Paris. Participants were aged more than 18 years, French-speaking and had injected substances the month before enrolment. MEASUREMENTS: We measured the impact of DCR exposure on injection equipment sharing, HCV testing and the use of medications for opioid use disorder, after adjustment for significant correlates. We used a two-step Heckman mixed-effects probit model, which allowed us to take into account the correlation of repeated measures and to control for potential bias due to non-randomization between the two groups (DCR-exposed versus DCR-unexposed participants). FINDINGS: The difference of declared injection equipment sharing between PWID exposed to DCRs versus non-exposed was 10% (1% for those exposed versus 11% for those non-exposed, marginal effect = -0.10; 95% confidence interval = -0.18, -0.03); there was no impact of DCRs on HCV testing and OAT. CONCLUSIONS: In the French context, drug consumption rooms appear to have a positive impact on at-risk practices for infectious diseases such as human immunodeficiency virus (HIV) and hepatitis C virus.

Psychotherapies in opioid use disorder: toward a step-care model.

Opioid use disorder (OUD) is characterized by a lack of control in opioid use, resulting in psychological distress and deficits in interpersonal and social functioning. OUD is often associated with psychiatric comorbidities that increase the severity of the disorder. The consequences of OUD are dramatic in terms of increased morbi-mortality. Specific medications and psychotherapies are essential tools not only in the treatment of OUD but also in the prevention of suicide and overdoses. In our review, we assess the different types of psychotherapies (counseling, motivational interviewing, contingency management, cognitive-behavioral therapy, and dialectical-behavior therapy) that are delivered to opioid users, either associated or un-associated with OUD medications and/or medications for psychiatric disabilities. We describe the application of these therapies first to adult opioid users and then to adolescents. This work led us to propose a stepped-care model of psychotherapies for OUD which provided information to assist clinicians in decision-making regarding the selection of psychotherapeutic strategies according to patients' OUD severity.

The Intertwining of Posttraumatic Stress Symptoms, Alcohol, Tobacco or Nicotine Use, and the COVID-19 Pandemic: A Systematic Review.

BACKGROUND: Posttraumatic stress symptoms (PTSSs) and alcohol, tobacco, or nicotine use are frequently associated conditions. The COVID-19 pandemic has been a stressful situation globally and has worsened mental health conditions and addictions in the population. Our systematic review explores the links between PTSSs and (1) alcohol use and (2) tobacco or nicotine use during the COVID-19 pandemic. METHODS: We searched the PubMed, PsycINFO, and Web of Science databases for studies published between January 2020 and 16 December 2021. We included studies published in English concerning adults or adolescents. Included articles dealt simultaneously with the COVID-19 pandemic, PTSSs, and alcohol, tobacco, or nicotine use. The reports included were cross-sectional, longitudinal, or cohort studies. We categorized the reports according to the population explored. Our main outcomes are the impacts of PTSSs on (1) alcohol use and (2) tobacco and nicotine use and their relation to COVID-19-related stressors (worries, exposure, lockdown, and infection, either of self or relatives). RESULTS: Of the 503 reports identified, 44 were assessed for eligibility, and 16 were included in our review, encompassing 34,408 participants. The populations explored were the general population, healthcare workers, war veterans, patients with substance use disorders, and other vulnerable populations. Most studies were online surveys (14) with cross-sectional designs (11). Every study explored alcohol use, while only two assessed tobacco use. In most populations explored, a high level of PTSSs was associated with alcohol use increase. COVID-19-related stress was frequently correlated with either high PTSSs or alcohol use. In healthcare workers, PTSSs and alcohol use were not associated, while COVID-19 worries were related to both PTSSs and alcohol use. DISCUSSION: 1. PTSSs and increased alcohol use are frequently associated, while COVID-19 worries might trigger both conditions and worsen their association. Alcohol use increase may represent either an inadequate way of coping with PTSSs or a vulnerability amid the COVID-19 pandemic, leading to PTSSs. As most studies were cross-sectional online surveys, longitudinal prospective studies are needed to ascertain the direction of the associations between these conditions. These studies need to be sufficiently powered and control for potential bias and confounders. 2. Our review highlighted that research about PTSSs and tobacco or nicotine use is scarce.

Efficacy of repetitive transcranial magnetic stimulation (rTMS) for reducing consumption in patients with alcohol use disorders (ALCOSTIM): study protocol for a randomized controlled trial.

BACKGROUND: The number of people with an alcohol use disorder (AUD) was recently estimated to be 63.5 million worldwide. The global burden of disease and injury attributable to alcohol is considerable: about 3 million deaths, namely one in 20, were caused by alcohol in 2015. At the same time, AUD remains seriously undertreated. In this context, alternative or adjunctive therapies such as brain stimulation could play an important role. The early results of studies using repetitive transcranial magnetic stimulation (rTMS) suggest that stimulations delivered to the dorsolateral prefrontal cortex significantly reduce cravings and improve decision-making processes in various addictive disorders. We therefore hypothesize that rTMS could lead to a decrease in alcohol consumption in patients with AUD. METHODS/DESIGN: We report the protocol of a randomized, double-blind, placebo-controlled, parallel-group trial to evaluate the efficacy of rTMS on alcohol reduction in individuals diagnosed with AUD. The study will be conducted in 2 centers in France. Altogether, 144 subjects older than 18 years and diagnosed with AUD will be randomized to receive 5 consecutive twice-daily sessions of either active or sham rTMS (10 Hz over the right DLPFC, 2000 pulses per day). The main outcomes of the study will be changes in alcohol consumption within the 4 weeks after the rTMS sessions. Secondary outcome measures will include changes in alcohol consumption within the 24 weeks, alcohol cravings, clinical and biological improvements, effects on mood and quality of life, and cognitive and safety assessments, and, for smokers, an assessment of the effects of rTMS on tobacco consumption. DISCUSSION: Several studies have observed a beneficial effect of rTMS on substance use disorders by reducing craving, impulsivity, and risk-taking behavior and suggest that rTMS may be a promising treatment in addiction. However, to date, no studies have included sufficiently large samples and sufficient follow-up to confirm this hypothesis. The results from this large randomized controlled trial will give a better overview of the therapeutic potential of rTMS in AUD. TRIAL REGISTRATION: ClinicalTrials.gov NCT04773691. Registered on 26 February 2021 https://clinicaltrials.gov/ct2/show/NCT04773691?term=trojak&draw=2&rank=5 .

Impaired P100 among regular cannabis users in response to magnocellular biased visual stimuli.

Regular cannabis using causes vision impairment by affecting human retinal neurotransmission. However, studies less considered its impact on the subsequent visual cortical processing, key feature for the integration of the visual signal in brain. We aimed at investigating this purpose in regular cannabis users using spatial frequencies and temporal frequencies filtered visual stimuli. We recruited 45 regular cannabis users and 25 age-matched controls. We recorded visual evoked potentials during the projection of low spatial frequency (0.5 cycles/degree) or high spatial frequency gratings (15 cycles/degree), which were presented statically (0 Hz) or dynamically (8 Hz). We analyzed the amplitude, latency, and area under the curve of both P100 and N170, best EEG markers for early visual processing. Data were compared between groups by repeated measures ANCOVA. Results showed a significant decrease in P100 amplitude among regular cannabis users in low spatial frequency (F(1,67) = 4.43; p = 0.04) and in dynamic condition (F(1,67) = 4.35; p = 0.04). Analysis also reported a decrease in P100 area under the curve in regular cannabis users to low spatial frequency (F(1,67) = 4.31; p = 0.04) and in dynamic condition (F(1,67) = 7.65; p < 0.01). No effect was found on P100 latency, N170 amplitude, latency, or area under the curve. We found alteration of P100 responses to low spatial frequency and dynamic stimuli in regular cannabis users. This result could be interpreted as a preferential magnocellular impairment where such deficit could be linked to glutamatergic dysfunction. As mentioned in the literature, visual and electrophysiological anomalies in schizophrenia are related to a magnocellular dysfunction. Further studies are needed to clarify electrophysiological deficits in both populations. CLINICAL TRIALS REGISTRATION: Electrophysiological Study of the Functioning of Magnocellular Visual Pathway in Regular Cannabis Users (CAUSA MAP). [NCT02864680; ID 2013-A00097-38]. https://clinicaltrials.gov/ct2/show/NCT02864680?cond=Cannabis&cntry=FR&draw=2&rank=1.

Workaholism Prevention in Occupational Medicine: A Systematic Review.

INTRODUCTION: Given the extent of workaholism identified in the literature, it seems essential to consider effective preventive measures. The purpose of this article is to summarize literature data on possible collective and individual preventive measures against workaholism, especially in occupational medicine. METHOD: We conducted a systematic literature review in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. RESULTS: 155 articles were retrieved in March 2019, but only 15 well-designed studies providing concrete measures to prevent workaholism were included. The various measures were classified using the traditional distinction between three levels of prevention. At the first level of prevention, workaholism can be avoided by implementing a protective organizational culture. The second level of prevention rather focuses on individual training and counselling to address the negative consequences of workaholism. Finally, the third level of prevention combines cognitive and behavioral interventions that enable professional and social reintegration of workaholics. DISCUSSION: This literature review confirms the multifactorial origin of workaholism and the involvement of organizational factors, supporting the necessary contribution of companies in its prevention. This review also reinforces the growing perception of workaholism as a behavioral addiction. Occupational physicians play a key role in this preventive approach as they can influence both working conditions and individual care. The highlighted preventive measures seem to be not only favorable to workaholics, but also to companies. CONCLUSION: This review provides field tools that can be used at the various levels of workaholism prevention. Nevertheless, intervention studies are required to confirm the effectiveness of the measures presented.

Link Between Perception of Treatment Need and Craving Reports in Addiction.

BACKGROUND: Perception of treatment need (PTN), a component of clinical insight, is associated to negative addiction treatment outcomes when low. Our hypothesis was that lower PTN was associated with less craving when reported retrospectively, the most common measure of craving in clinical settings. OBJECTIVE: To explore the association between PTN and craving among a dataset of subjects with severe substance use disorders. METHODS: Participants were recruited from outpatient addiction clinic admissions or harm reduction program services. Good and low PTN were based on consistency between severe addiction (at least six DSM-5 criteria) and self-report need for addiction treatment from the Addiction Severity Index. Craving was retrospectively characterized over the past 30 days. Multiple regression analyses were conducted. RESULTS: Participants with low PTN (n = 97) retrospectively reported less frequent and intense episodes of craving, compared with participants with good PTN (n = 566) after controlling for sociodemographic factors, addiction type, and severity (p < 0.0001). CONCLUSION: Low perception of treatment need among subjects with severe addictions is associated to less retrospective report of craving, which may contribute to reduced efficiency of treatment. Further studies are needed to explore the mechanisms of the association.

Spatial localization of retinal anomalies in regular cannabis users: The relevance of the multifocal electroretinogram.

Widely used in industrialized countries, cannabis is a neuromodulator substance. The cannabinoid system is present at critical stages of retinal processing. We have recently shown a delay in bipolar and ganglion cell responses in regular cannabis users, as observed using flash (fERG) and pattern (PERG) electroretinogram. Although the results obtained during these tests provide information about global retinal responses, they do not give any indication about the spatial localization of the anomalies that were detected. The latter may be analyzed, however, by means of multifocal electroretinogram (mfERG). We recorded the mfERG responses in 49 regular cannabis users and 21 healthy subjects. The amplitudes and implicit times of the mfERG N1, P1 and N2 waves were recorded. The results showed that in regular cannabis users: in the <2° region, a significant increase in the N2 implicit time (p = 0.037); in the 2-5° region, a significant increase in the N2 (p = 0.018) and P1 (p = 0.046) implicit times; in the 5-10° region, a significant increase in the P1 (p = 0.006) and N1 (p = 0.034) implicit times; and in the 10-15° region, a significant increase in the P1 implicit time (p = 0.014). An isolated decrease in the N1 amplitude in the 2-5° region (p = 0.044) was also found. This indicates that there is a delay in the transmission of visual information from the central retina to the near periphery in cannabis users suggesting potential alterations in precise and color vision.

Impact of drug consumption rooms on risk practices and access to care in people who inject drugs in France: the COSINUS prospective cohort study protocol.

INTRODUCTION: The high prevalence of hepatitis C and the persistence of HIV and hepatitis C virus (HCV) risk practices in people who inject drugs (PWID) in France underlines the need for innovative prevention interventions. The main objective of this article is to describe the design of the COSINUS cohort study and outline the issues it will explore to evaluate the impact of drug consumption rooms (DCR) on PWID outcomes. Secondary objectives are to assess how DCR (a) influence other drug-related practices, such as the transition from intravenous to less risky modes of use, (b) reduce drug use frequency/quantity, (c) increase access to treatment for addiction and comorbidities (infectious, psychiatric and other), (d) improve social conditions and (e) reduce levels of violence experienced and drug-related offences. COSINUS will also give us the opportunity to investigate the impact of other harm reduction tools in France and their combined effect with DCR on reducing HIV-HCV risk practices. Furthermore, we will be better able to identify PWID needs. METHODS AND ANALYSIS: Enrollment in this prospective multi-site cohort study started in June 2016. Overall, 680 PWID in four different cities (Bordeaux, Marseilles, Paris and Strasbourg) will be enrolled and followed up for 12 months through face-to-face structured interviews administered by trained staff to all eligible participants at baseline (M0), 3 month (M3), 6 month (M6) and 12 month (M12) follow-up visits. These interviews gather data on socio-demographic characteristics, past and current drug and alcohol consumption, drug-use related practices, access to care and social services, experience of violence (as victims), offences, other psychosocial issues and perception and needs about harm reduction interventions and services. Longitudinal data analysis will use a mixed logistic model to assess the impact of individual and structural factors, including DCR attendance and exposure to other harm reduction services, on the main outcome (HIV-HCV risk practices). ETHICS AND DISSEMINATION: This study was reviewed and approved by the institutional review board of the French Institute of Medical Research and Health (opinion number: 14-166). The findings of this cohort study will help to assess the impact of DCR on HIV-HCV risk practices and other psycho-social outcomes and trajectories. Moreover, they will enable health authorities to shape health and harm reduction policies according to PWID needs. Finally, they will also help to improve current harm reduction and therapeutic interventions and to create novel ones.

Cannabis use and human retina: The path for the study of brain synaptic transmission dysfunctions in cannabis users.

Owing to the difficulty of obtaining direct access to the functioning brain, new approaches are needed for the indirect exploration of brain disorders in neuroscience research. Due to its embryonic origin, the retina is part of the central nervous system and is well suited to the investigation of neurological functions in psychiatric and addictive disorders. In this review, we focus on cannabis use, which is a crucial public health challenge, since cannabis is one of the most widely used addictive drugs in industrialized countries. We first explain why studying retinal function is relevant when exploring the effects of cannabis use on brain function. Next, we describe both the retinal electrophysiological measurements and retinal dysfunctions observed after acute and regular cannabis use. We then discuss how these retinal dysfunctions may inform brain synaptic transmission abnormalities. Finally, we present various directions for future research on the neurotoxic effects of cannabis use.

Time perception and impulsivity: A proposed relationship in addictive disorders.

Addictive disorders are characterized by impulsive behavior that leads to difficulties in preventing certain behaviors despite negative consequences. This symptom predisposes to a vulnerability in developing addictive disorders and is also aggravated by the addiction process itself. As such, understanding the underlying mechanisms of impulsivity is a challenge for understanding the pathophysiology of addiction. One common link between impulsivity and addiction is that both involve actions and decisions that are realized faster than they should be in time. Impulsive traits increase the tendency to choose immediate gratification instead of delayed gratification even when preferred. This observation suggests a relationship between impulsivity and time processing. To better understand this relationship, we reviewed the literature that describes the relationship between time processing and impulsivity in addictive disorders in humans. Despite a lack of literature concerning this question in alcohol, cannabis and gambling disorders, we highlight that addictive behaviors are a good model for understanding the pathophysiology of impulsivity, and could help us to better understand the relationship between time perception and impulsivity.

Delayed bipolar and ganglion cells neuroretinal processing in regular cannabis users: The retina as a relevant site to investigate brain synaptic transmission dysfunctions.

Cannabis use is widespread worldwide, but the impact of smoking cannabis regularly on brain synaptic transmission has only been partially elucidated. The retina is considered as an easy means of determining dysfunction in brain synaptic transmission. The endocannabinoid system is involved in regulating retinal synaptic transmission, which might also be affected by tobacco. Previous preliminary results have shown impairments in retinal ganglion cell response in cannabis users. Here, we test the extent to which earlier retinal levels-bipolar cells and photoreceptors-are affected in cannabis users, i.e. by the association of tobacco and cannabis. We recorded pattern (PERG) and flash (fERG) ERG in 53 regular cannabis users and 29 healthy controls. Amplitude and peak time of P50 and N95 (PERG) and of a- and b-waves (fERG) were evaluated. Cannabis users showed a significant increase in PERG N95 peak time and in fERG light-adapted 3.0 b-wave peak time, compared with controls (p = 0.0001 and p = 0.002, respectively; Mann-Whitney U test). No significant difference was found between the groups in terms of wave amplitude (p = 0.525 and p = 0.767 for the N95 and light-adapted 3.0 b-wave amplitude respectively; Mann-Whitney U test). The results demonstrated delayed ganglion and bipolar cell responses in cannabis users. These results reflect a delay in the transmission of visual information from the retina to the brain. This retinal dysfunction may be explained by an effect of cannabis use on retinal synaptic transmission. Main limitations of these results concern tobacco and alcohol use that differed between groups. The consequences of these anomalies on visual perception along with the molecular mechanisms underlying this retinal dysfunction should be explored in future human and animal studies.

Focusing on the Opioid System for Addiction Biomarker Discovery.

Substance use disorders (SUD) and behavioral addictions are devastating conditions that impose a severe burden on all societies, and represent difficult challenges for clinicians. Therefore, biomarkers are urgently needed to help predict vulnerability, clinical course, and response to treatment. Here, we elaborate on the potential for addiction biomarker discovery of the opioid system, particularly within the emerging framework aiming to probe opioid function in peripheral tissues. Mu, delta, and kappa opioid receptors all critically regulate neurobiological and behavioral processes that define addiction, and are also targeted by major pharmacotherapies used in the management of patients with SUD. We propose that opioid biomarkers may have the potential to improve and guide diagnosis and therapeutic decisions in the addiction field.

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.

Impaired contrast sensitivity at low spatial frequency in cannabis users with early onset.

The regular use of cannabis generates pronounced cognitive disorders, especially in users who begin before the age of 15-16. However, less is known about the impact of regular cannabis on visual function, especially in the case of early onset. Cannabinoid receptors (CB1) are expressed in areas of the visual system, like the thalamus and primary cortex, which might originate sensory disorders. Hence, we measured contrast sensitivity (CS) in three groups, i.e. cannabis users with late onset of cannabis use (after 16 years old), cannabis users with early onset". We used a constant method which allowed us to control for biased responses. Stimuli were presented at high and low spatial frequencies and in both static and dynamic conditions (8Hz). As contrast sensitivity is measured behaviorally based on an explicit response and could thus be impacted by attentional or vigilance disorders, participants' attention and vigilance were carefully monitored by means of the D2 test, CPT-AX for attention and pupillography for vigilance. Cannabis users with early onset were significantly impaired only at low spatial frequency. This effect was independent of response bias, vigilance and attention. These results show for the first time that early cannabis use impacts contrast sensitivity at low spatial frequency.

Outcome of Non-Invasive Brain Stimulation in Substance Use Disorders: A Review of Randomized Sham-Controlled Clinical Trials.

Non-invasive brain stimulation (NIBS) might be a new approach to treat substance use disorders (SUD). A systematic review and critical analysis was performed to identify potential therapeutic effects of NIBS on addictions. A search of the Medline database was conducted for randomized sham-controlled trials using NIBS in the field of addiction and published until August 2016. Twenty-six studies in various SUD met the inclusion criteria. Converging evidence indicates that NIBS might be a promising mean to treat patients with alcohol and tobacco use disorders, by acting on craving reduction and other mechanisms such as improvement in cognitive dysfunctions.

The role of the retina in visual hallucinations: A review of the literature and implications for psychosis.

Visual hallucinations are a psychotic symptom present in numerous clinical conditions such as eye disease, Parkinsonian syndromes, neurodegenerative disorders and psychosis. Alteration of low level visual processing is a common feature in these clinical conditions, and various stages of processing from the retina to visual cortices are involved. We undertook a literature review of abnormalities of the retina and their potential link with the occurrence of VHs in these clinical conditions of interest. We found that structural and functional abnormalities of the retina are frequently present. In Parkinson disease and eye disease, VHs have been related to dysfunctions of the retina. By contrast, in neurodegenerative disorders and psychosis, possible links have yet not been explored. We show that structural or functional abnormalities of the retina are given little consideration in cognitive models of VHs, which primarily postulate an alteration of sensory visual processing and a top-down attentional process. We conclude that contrast sensitivity measures and an exhaustive exploration of the retinal functions using the clinical electroretinography standards of the International Society for the Clinical Electrophysiology of Vision (ISCEV) are needed to explore retinal involvement in the occurrence of visual hallucinations.

Acute impact of caffeinated alcoholic beverages on cognition: A systematic review.

INTRODUCTION: Energy drinks are popular beverages that are supposed to counteract sleepiness, increase energy, maintain alertness and reduce symptoms of hangover. Cognitive enhancing seems to be related to many compounds such as caffeine, taurine and vitamins. Currently, users mostly combine psychostimulant effects of energy drinks to counteract sedative effects of alcohol. However, recent literature suggests that this combination conducts to feel less intoxicated but still impaired. The goal of the present article is to review cognitive impact and subjective awareness in case of caffeinated alcoholic beverage (CAB) intoxication. METHOD: PubMed (January 1960 to March 2016) database was searched using the following terms: cognitive impairments, alcohol, energy drinks; cognition, alcohol, caffeine. RESULTS: 99 papers were found but only 12 randomized controlled studies which explored cognitive disorders and subjective awareness associated with acute CAB or AED (alcohol associated with energy drinks) intoxication were included. DISCUSSION: The present literature review confirmed that energy drinks might counteract some cognitive deficits and adverse effects of alcohol i.e. dry mouth, fatigue, headache, weakness, and perception of intoxication due to alcohol alone. This effect depends on alcohol limb but disappears when the complexity of the task increases, when driving for example. Moreover, studies clearly showed that CAB/AEDs increase impulsivity which conducts to an overconsumption of alcohol and enhanced motivation to drink compared to alcohol alone, potentiating the risk of developing addictive behaviors. This is a huge problem in adolescents with high impulsivity and immature decision making processes. CONCLUSION: Although energy drinks counteract some cognitive deficits due to alcohol alone, their association promotes the risk of developing alcohol addiction. As a consequence, it is necessary to better understand the neurobiological mechanisms underlying these interactions in order to better prevent the development of alcohol dependence.