The long-term cognitive consequences of adolescent exposure to recreational drugs of abuse

Correlation between cerebral neurotransmitters levels by proton magnetic resonance spectroscopy and HbA1c in patients with type 2 diabetes

BACKGROUND

Cognitive dysfunction is the main manifestation of central neuropathy. Although cognitive impairments tend to be overlooked in patients with diabetes mellitus (DM), there is a growing body of evidence linking DM to cognitive dysfunction. Hyperglycemia is closely related to neurological abnormalities, while often disregarded in clinical practice. Changes in cerebral neurotransmitter levels are associated with a variety of neurological abnormalities and may be closely related to blood glucose control in patients with type 2 DM (T2DM).

AIM

To evaluate the concentrations of cerebral neurotransmitters in T2DM patients exhibiting different hemoglobin A1c (HbA1c) levels.

METHODS

A total of 130 T2DM patients were enrolled at the Department of Endocrinology of Shanghai East Hospital. The participants were divided into four groups according to their HbA1c levels using the interquartile method, namely Q1 (< 7.875%), Q2 (7.875%-9.050%), Q3 (9.050%-11.200%) and Q4 (≥ 11.200%). Clinical data were collected and measured, including age, height, weight, neck/waist/hip circumferences, blood pressure, comorbidities, duration of DM, and biochemical indicators. Meanwhile, neurotransmitters in the left hippocampus and left brainstem area were detected by proton magnetic resonance spectroscopy.

RESULTS

The HbA1c level was significantly associated with urinary microalbumin (mALB), triglyceride, low-density lipoprotein cholesterol (LDL-C), homeostasis model assessment of insulin resistance (HOMA-IR), and beta cell function (HOMA-β), N-acetylaspartate/creatine (NAA/Cr), and NAA/choline (NAA/Cho). Spearman correlation analysis showed that mALB, LDL-C, HOMA-IR and NAA/Cr in the left brainstem area were positively correlated with the level of HbA1c (P < 0.05), whereas HOMA-β was negatively correlated with the HbA1c level (P < 0.05). Ordered multiple logistic regression analysis showed that NAA/Cho [Odds ratio (OR): 1.608, 95% confidence interval (95%CI): 1.004-2.578, P < 0.05], LDL-C (OR: 1.627, 95%CI: 1.119-2.370, P < 0.05), and HOMA-IR (OR: 1.107, 95%CI: 1.031-1.188, P < 0.01) were independent predictors of poor glycemic control.

CONCLUSION

The cerebral neurotransmitter concentrations in the left brainstem area in patients with T2DM are closely related to glycemic control, which may be the basis for the changes in cognitive function in diabetic patients.

Assessment of Hippocampal-Related Behavioral Changes in Adolescent Rats of both Sexes Following Voluntary Intermittent Ethanol Intake and Noise Exposure: A Putative Underlying Mechanism and Implementation of a Non-pharmacological Preventive Strategy

Ethanol (EtOH) intake and noise exposure are particularly concerning among human adolescents because the potential to harm brain. Unfortunately, putative underlying mechanisms remain to be elucidated. Moreover, implementing non-pharmacological strategies, such as enriched environments (EE), would be pertinent in the field of neuroprotection. This study aims to explore possible underlying triggering mechanism of hippocampus-dependent behaviors in adolescent animals of both sexes following ethanol intake, noise exposure, or a combination of both, as well as the impact of EE. Adolescent Wistar rats of both sexes were subjected to an intermittent voluntary EtOH intake paradigm for one week. A subgroup of animals was exposed to white noise for two hours after the last session of EtOH intake. Some animals of both groups were housed in EE cages. Hippocampal-dependent behavioral assessment and hippocampal oxidative state evaluation were performed. Results show that different hippocampal-dependent behavioral alterations might be induced in animals of both sexes after EtOH intake and sequential noise exposure, that in some cases are sex-specific. Moreover, hippocampal oxidative imbalance seems to be one of the potential underlying mechanisms. Additionally, most behavioral and oxidative alterations were prevented by EE. These findings suggest that two frequently found environmental agents may impact behavior and oxidative pathways in both sexes in an animal model. In addition, EE resulted a partially effective neuroprotective strategy. Therefore, it could be suggested that the implementation of a non-pharmacological approach might also potentially provide neuroprotective advantages against other challenges. Finally, considering its potential for translational human benefit might be worth.

Risky alcohol use during youth: Impact on emotion, cognitive networks, and resting-state EEG activity

The identification of the risk factors of alcohol consumption in youths is crucial for early interventions focused on reducing harmful alcohol use. In our study, 82 college students (40 healthy control (CO group) and 42 with risky alcohol use (RAU group) determined by AUDIT questionnaire) between the ages of 18 and 25 years underwent a comprehensive neuropsychological assessment covering emotional and cognitive functioning. Their resting-state activity was also recorded with an EEG for 10 min with their eyes open (EO) and 10 min with their eyes closed (EC) and analyzed using the Fitting Oscillations & One-Over-F (FOOOF) paradigm. After adjusting for sex, those in the RAU group had higher emotional dysregulation and impulsivity traits. The RAU girls presented more emotional regulation problems, such as dysregulation and negative urgency compared with the RAU boys. The RAU youths had significantly worse functioning in several cognitive domains, such as sustained attention, verbal memory, and executive functions. Cognitive network analysis revealed a different pattern of connections in each group showing that in the RAU group, the verbal memory domain had the highest connection with other cognitive functions. The EEG analyses did not reveal any significant differences between the CO and the RAU groups. However, we observed only in the EO condition that boys the from the RAU group displayed a higher theta/beta ratio than the RAU girls, whereas these differences were not observed within the CO group. Our findings highlight the need to explore more deeply the emotional, cognitive and brain changes underlying the RAU in young people.

Alcohol Consumption During Adolescence Alters the Cognitive Function in Adult Male Mice by Persistently Increasing Levels of DUSP6

Binge alcohol drinking during adolescence has long-term effects on the adult brain that alter brain structure and behaviors, but the underlying mechanisms remain poorly understood. Extracellular signal-regulated kinase (ERK) is involved in the synaptic plasticity and pathological brain injury by regulating the expression of cyclic adenosine monophosphate response element binding protein (CREB) and brain-derived neurotrophic factor (BDNF). Dual-specificity phosphatase 6 (DUSP6) is a critical effector that dephosphorylates ERK1/2 to control the basal tone, amplitude, and duration of ERK signaling. To explore DUSP6 as a regulator of ERK signaling in the mPFC and its impact on long-term effects of alcohol, a male mouse model of adolescent intermittent alcohol (AIA) exposure was established. Behavioral experiments showed that AIA did not affect anxiety-like behavior or sociability in adulthood, but significantly damaged new object recognition and social recognition memory. Molecular studies further found that AIA reduced the levels of pERK-pCREB-BDNF-PSD95/NR2A involved in synaptic plasticity, while DUSP6 was significantly increased. Intra-mPFC infusion of AAV-DUSP6-shRNA restored the dendritic spine density and postsynaptic density thickness by reversing the level of p-ERK and its downstream molecular expression, and ultimately repaired adult cognitive impairment caused by chronic alcohol exposure during adolescence. These findings indicate that AIA exposure inhibits ERK-CREB-BDNF-PSD95/NR2A by increasing DUSP6 in the mPFC in adulthood that may be associated with long-lasting cognitive deficits.

Narrative review: Revised Principles and Practice Recommendations for Adolescent Substance Use Treatment and Policy

OBJECTIVE

In 2014, the U.S. National Institute on Drug Abuse released the "Principles of Adolescent Substance Use Disorder Treatment," summarizing previously established evidence and outlining principles of effective assessment, treatment, and aftercare for substance use disorders (SUD). Winters et al. (2018) updated these principles to be developmentally appropriate for adolescents. This review builds on that formative work and recommends updated adolescent assessment, treatment, and aftercare principles and practices.

METHOD

The Cochrane, MEDLINE-PubMed, and PsychInfo databases were searched for relevant studies with new data about adolescent substance use services. This article updates the 13 original principles; condenses the 8 original modalities into 5 practices; and highlights implications for public policy approaches, future funding, and research.

RESULTS

Key recommendations from the principles include integrating care for co-occurring mental health disorders and SUDs, improving service accessibility including through the educational system, maintaining engagement, and addressing tension between agencies when collaborating with other youth service systems. Updates to the treatment practices include adoption of Screening, Brief Intervention and Referral to Treatment (SBIRT), investment in social programs and family involvement in treatment, expanding access to behavioral therapies and medications, increasing funding to harm reduction services, supporting reimbursement for continuing care services, and increasing investment in research.

CONCLUSION

These revised principles of adolescent assessment, treatment, and aftercare approaches and practices aim to establish guidance and evidence-based practices for treatment providers, while encouraging necessary support from policymakers and funding agencies to improve the standard of care for adolescent SUD services.

Machine Learning of Functional Connectivity to Biotype Alcohol and Nicotine Use Disorders

BACKGROUND

Magnetic resonance imaging provides noninvasive tools to investigate alcohol use disorder (AUD) and nicotine use disorder (NUD) and neural phenotypes for genetic studies. A data-driven transdiagnostic approach could provide a new perspective on the neurobiology of AUD and NUD.

METHODS

Using samples of individuals with AUD (n = 140), individuals with NUD (n = 249), and healthy control participants (n = 461) from the UK Biobank, we integrated clinical, neuroimaging, and genetic markers to identify biotypes of AUD and NUD. We partitioned participants with AUD and NUD based on resting-state functional connectivity (FC) features associated with clinical metrics. A multitask artificial neural network was trained to evaluate the cluster-defined biotypes and jointly infer AUD and NUD diagnoses.

RESULTS

Three biotypes-primary NUD, mixed NUD/AUD with depression and anxiety, and mixed AUD/NUD-were identified. Multitask classifiers incorporating biotype knowledge achieved higher area under the curve (AUD: 0.76, NUD: 0.74) than single-task classifiers without biotype differentiation (AUD: 0.61, NUD: 0.64). Cerebellar FC features were important in distinguishing the 3 biotypes. The biotype of mixed NUD/AUD with depression and anxiety demonstrated the largest number of FC features (n = 5), all related to the visual cortex, that significantly differed from healthy control participants and were validated in a replication sample (p < .05). A polymorphism in TNRC6A was associated with the mixed AUD/NUD biotype in both the discovery (p = 7.3 × 10-5) and replication (p = 4.2 × 10-2) sets.

CONCLUSIONS

Biotyping and multitask learning using FC features can characterize the clinical and genetic profiles of AUD and NUD and help identify cerebellar and visual circuit markers to differentiate the AUD/NUD group from the healthy control group. These markers support a new growing body of literature.

Co-Use of Tobacco Products and Cannabis Is Associated with Absenteeism and Lower Grades in California High School Students

OBJECTIVE

To examine the association between co-use of commercial tobacco product (hereafter referred to as tobacco) and cannabis with educational outcomes among high school students.

STUDY DESIGN

We analyzed high school student data from the 2021-2022 California Healthy Kids Survey (n = 287 653). Current (past-month) or ever tobacco and cannabis use was categorized as co-use, only tobacco or cannabis, or neither. Two self-reported educational outcomes were examined: absenteeism and grades. Adjusted logistic and linear regression models were used to examine the association between tobacco/cannabis use and absenteeism or grades, respectively. Estimates were adjusted for individual, peer, and school covariates, and clustering within schools.

RESULTS

Current co-use of tobacco and cannabis was more than double the use of only tobacco (3.7% vs 1.7%) and similar to only cannabis (3.7%). Almost 18% of students reported absenteeism. Compared with students who used neither substance, students with current co-use had greater odds of absenteeism (aOR 1.41, 95% CI 1.33-1.49) and lower grades (β = -0.87, 95% CI -0.92 to -0.82). Compared with students using tobacco alone, students with co-use also had a significant elevated odds of absenteeism (aOR 1.19, 95% CI 1.10-1.29) and lower grades (β = -0.39, 95% CI -0.46 to -0.32). Similar results were found for students who ever used tobacco and cannabis.

CONCLUSIONS

California youth who co-use tobacco and cannabis were most likely to have absenteeism and lower grades. Comprehensive efforts to prevent or reduce youth substance use may improve educational outcomes.

Fine-Regional Role of the Claustrum in Anxiety and Higher Sensitivity to Cocaine in Adolescent Cocaine-Exposed Male Mice during Adulthood

Adolescent cocaine exposure (ACE) induces anxiety and higher sensitivity to substances abuse during adulthood. Here, we show that the claustrum is crucial for controlling these psychiatric problems in male mice. In anxiety-like behavioral tests, the CaMKII-positive neurons in the median portion of the claustrum (MClaustrum) were triggered, and local suppression of these neurons reduced the anxiety-like behavior in ACE mice during adulthood. In contrast, the CaMKII-positive neurons in the anterior portion of the claustrum (AClaustrum) were more activated in response to subthreshold dose of cocaine induced conditioned place preference (CPP), and local suppression of these neurons blocked the acquisition of cocaine CPP in ACE mice during adulthood. Our findings for the first time identified the fine-regional role of the claustrum in regulating the anxiety and susceptibility to cocaine in ACE mice during adulthood, extending our understanding of the claustrum in substance use disorder.

Adolescent alcohol and nicotine exposure alters the adult response to alcohol use

Adolescence through young adulthood is a unique period of neuronal development and maturation. Numerous agents can alter this process, resulting in long-term neurological and biological consequences. In the clinical literature, it is frequently reported that adolescent alcohol consumption increases the propensity to develop addictions, including alcohol use disorder (AUD), during adulthood. A general limitation of both clinical and human pre-clinical adolescent alcohol research is the high rate of co-using/abusing more than one drug during adolescence, such as co-using/abusing alcohol with nicotine. A primary goal of basic research is elucidating neuroadaptations produced by adolescent alcohol exposure/consumption that promote alcohol and other drug self-administration in adulthood. The long-term goal is to develop pharmacotherapeutics for the prevention or amelioration of these neuroadaptations. This review will focus on studies that have examined the effects of adolescent alcohol and nicotine exposure on adult alcohol consumption, the hypersensitivity of the mesolimbic dopaminergic system, and enhanced responses not only to alcohol but also to nicotine during adulthood. Again, the long-term goal is to identify potential cholinergic agents to prevent or ameliorate the consequences of, peri-adolescent alcohol abuse.

"His heart is hardening, but his BRAIN is softening": Life experiences of adolescents using psychoactive substances: A qualitative study

PURPOSE

The aim of the research was to portray the life experiences of adolescents using psychoactive substances with regard to their substance use.

DESIGN AND METHODS

This study was carried out in a descriptive phenomenological design, which is a qualitative research method. A purposeful sampling method, was used. The sample consisted of 15 adolescents who were treated for a history of substance use. The data were collected by the face-to-face individual interview method. A personal information form and a semi-structured interview form were used to collect data. The content analysis approach proposed by Graneheim and Lundman was used in the analysis of the data. Data were analyzed using the N-VIVO-10 Pro-package program.

RESULTS

Four main themes and thirteen sub-themes were determined: experiences before substance use (sub-themes: life before substance use, predisposing factors for substance use), experiences during substance use (sub-themes: symptoms of addiction, problems caused by substance use, family attitude to substance use, the meaning attached to substances) and experiences of the treatment process (sub-themes: motivation, difficulties experienced during treatment, the need for support, treatment results), prevention recommendations (sub-themes: for peers, for families, for society).

CONCLUSIONS

Many individual, family and social risk factors had an effect on the adolescents starting to use the substances. They were exposed to negative physical, mental, economic, social and life experiences.

PRACTICE IMPLICATIONS

Nurses working with adolescents who use substances can implement nursing interventions such as prevention activities, counselling, health education, coping and strengthening self-esteem in individual and school based interventions.

Consequences of adolescent drug use

Substance use in adolescence is a known risk factor for the development of neuropsychiatric and substance use disorders in adulthood. This is in part due to the fact that critical aspects of brain development occur during adolescence, which can be altered by drug use. Despite concerted efforts to educate youth about the potential negative consequences of substance use, initiation remains common amongst adolescents world-wide. Additionally, though there has been substantial research on the topic, many questions remain about the predictors and the consequences of adolescent drug use. In the following review, we will highlight some of the most recent literature on the neurobiological and behavioral effects of adolescent drug use in rodents, non-human primates, and humans, with a specific focus on alcohol, cannabis, nicotine, and the interactions between these substances. Overall, consumption of these substances during adolescence can produce long-lasting changes across a variety of structures and networks which can have enduring effects on behavior, emotion, and cognition.

Immersive virtual plus-maze to examine behavior and psychophysiological-related variables in young people with problematic alcohol and cannabis consumption

Stressful events appear to be risky situations that can precipitate the consumption of drugs. One way to recreate stressful contexts, in an ecological and controlled method, is through immersive virtual reality (VR). In our study, we designed the scenario of an elevated plus-maze (EPM) using VR, which is widely used in animal models to assess unconditioned anxiety. This task allowed us to analyze the behavioral, psychophysiological (heart rate and electrodermal activity), and hormonal response (salivary cortisol and Alpha-amylase) to this stressful situation in different moments (before VR task (anticipation), at the end of the task and 10 minutes later) in young people with problematic alcohol use (AU, n = 27), alcohol combined with cannabis consumption (AU + C, n = 10), as well as in a control group (CO, n = 33). Behavioral analysis revealed that the AU group displayed fewer entries into open arms than the CO group, whereas both experimental groups spent less time at the end of the open arms, as well as lower time by look down index compared to the CO group. Moreover, our VR EPM induced different psychophysiological responses in the different moments measured. In general, electrodermal activity seemed to be a good biomarker of recovery from a stressful situation, as once the exposure to the stressful situation ended, the AU + C group took longer to recover compared to the CO group. Regarding hormonal analyses, we observed a similar response pattern in all groups suggesting that our VR task was able to activate both stress systems. The alpha-amylase to cortisol ratio, proposed as a biomarker of stress systems dysregulation, was higher in the group of young participants with alcohol abuse. Interestingly, our VR EPM was able to induce a slight alcohol craving in both experimental groups. In conclusion, our results suggest certain subtle behavioral and physiological differences that could be used to detect young individuals at risk of future severe addictions or other stress-related comorbidities. Moreover, it could help us to develop prevention strategies focused on emotional, cognitive, and psychophysiological aspects.

Earthquake exposure during adolescence and later-life depressive symptoms: A national cross-sectional survey

Background

This study aimed to examine the association between exposure to the 1976 Great Tangshan Earthquake (GTE) in adolescence and later-life depressive symptoms and to investigate the potential mechanisms underlying this association.

Methods

Data were from the 2015 China Health and Retirement Longitudinal Study (CHARLS). The 10-item short form of the Center for Epidemiologic Studies Depression scale (CESD-10) was chosen to measure depressive symptoms. We used the difference-in-difference (DID) method, binary logistic regression models, and multilevel logistic regression models to explore the association of earthquake exposure during adolescence with later-life depressive symptoms. Additionally, multilevel mediation analysis with structural equation modeling (MMSEM) was conducted to investigate potential mechanisms.

Results

We identified that adolescent exposure to earthquakes was related to a lower risk of depressive symptoms in later life (OR = 0.90, P = 0.019; OR = 0.48, P = 0.031; OR = 0.47, P = 0.034, respectively). However, this significant association was observed only in females (OR = 0.83, P = 0.028; OR = 0.46, P = 0.053; OR = 0.42, P = 0.037, respectively). Moreover, social activity participation played a mediating role in the association between exposure to earthquakes in adolescence and later-life depressive symptoms.

Conclusions

We observed a lower risk of depressive symptoms in later life in survivors of earthquake exposure during adolescence. Further, we found the mediating role of social participation in the association between earthquake exposure in adolescence and later-life depressive symptoms, which gives support for the posttraumatic growth (PTG) theory. Our findings imply that, in order to lower the risk of depression in later life following exposure to a natural disaster in adolescence, it is necessary to take into account the buffering effect of social participation.

Unpacking disparities in substance-related outcomes among racial, ethnic, sexual, and gender minoritized groups during adolescence and emerging adulthood

OBJECTIVE

Alcohol and other drug (AOD) use increases substantially from adolescence to emerging adulthood, and recent longitudinal studies show disparities in AOD-related outcomes by racial and ethnic, as well as sexual and gender minority (SGM), identities. Greater insight is needed into how individual, social, and environmental contexts interact and affect such disparities, as well as why disparate outcomes are found across different domains (e.g., social, educational, economic), even after accounting for intensity of use. This commentary addresses these important and timely issues.

METHOD

We provide a brief overview of the literature, including our own team's work over the last 14 years, to identify and understand disparities in AOD-related outcomes during adolescence and emerging adulthood across individuals with different racial and ethnic, and sexual and gender, identities. We then discuss paths forward to advance research and build a stronger evidence base, leading to the development and identification of effective interventions that can help mitigate disparities among historically marginalized adolescents and emerging adults.

RESULTS

Existing research highlights the need for further longitudinal work in several areas, including addressing contextual factors at various levels (e.g., individual, social, environmental) that may contribute to outcomes for different groups of individuals, developing and testing culturally appropriate AOD-related services, giving greater consideration to intersectionality of multiple minority identities, and using novel statistical approaches to help improve the estimation of differences across smaller subgroups of individuals in existing cohorts.

CONCLUSIONS

To inform prevention programming and policy for improving health and well-being of historically marginalized populations, it is important to continue our efforts to understand disparities in AOD-related outcomes using multidisciplinary, equity, and intersectionality lenses. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Morphine exposure during adolescence induces enduring social changes dependent on adolescent stage of exposure, sex, and social test

Drug exposure during adolescence, when the 'reward' circuitry of the brain is developing, can permanently impact reward-related behavior. Epidemiological studies show that opioid treatment during adolescence, such as pain management for a dental procedure or surgery, increases the incidence of psychiatric illness including substance use disorders. Moreover, the opioid epidemic currently in the United States is affecting younger individuals raising the impetus to understand the pathogenesis of the negative effects of opioids. One reward-related behavior that develops during adolescence is social behavior. We previously demonstrated that social development occurs in rats during sex-specific adolescent periods: early to mid-adolescence in males (postnatal day (P)30-40) and pre-early adolescence in females (P20-30). We thus hypothesized that morphine exposure during the female critical period would result in adult sociability deficits in females, but not males, and morphine administered during the male critical period would result in adult sociability deficits in males, but not females. We found that morphine exposure during the female critical period primarily resulted in deficits in sociability in females, while morphine exposure during the male critical period primarily resulted in deficits in sociability primarily in males. However, depending on the test performed and the social parameter measured, social alterations could be found in both sexes that received morphine exposure at either adolescent stage. These data indicate that when drug exposure occurs during adolescence, and how the endpoint data are measured, will play a large role in determining the effects of drug exposures on social development.

Effect of COVID-19 Lockdown on Substance Use Among Middle School and High School Students: A Natural Experiment

OBJECTIVE

Research on COVID-19's effect on substance use is mixed, and few studies have focused on adolescents. We assessed whether implementation of the COVID-19 lockdown affected substance use and changed perceptions of psychoactive substance availability in middle and high school students.

METHODS

We assessed self-reported use and perceived availability of alcohol, tobacco cigarettes, electronic cigarettes, marijuana, synthetic marijuana, nonprescribed prescription drugs, and illicit drugs (heroin, inhalants) among middle and high school respondents aged 11-18 years to the Rhode Island Student Survey (N = 17 751). An administrative pause because of COVID-19 lockdowns allowed us to divide results into surveys completed before (January through March 2020; n = 13 259) and after (November 2020 through May 2021; n = 4492) the lockdown implementation. We determined the effects of the COVID-19 lockdown using logistic regression models, adjusting for age, gender/sexual orientation, middle/high school level, and city/town classification.

RESULTS

After the COVID-19 lockdown implementation, the odds of respondents using psychoactive substances decreased, with the largest decreases occurring for prescription drugs (odds ratio [OR] = 0.39; 95% CI, 0.28-0.54) and inhalants (OR = 0.37; 95% CI, 0.26-0.53). The odds of respondents perceiving difficulties in obtaining psychoactive substances significantly increased after lockdown implementation, with the largest increases occurring for prescription drugs (OR = 1.53; 95% CI, 1.39-1.69) and illicit drugs (OR = 1.65; 95% CI, 1.44-1.88).

CONCLUSIONS

COVID-19 lockdown implementation was associated with a decreased perception of availability of psychoactive substances and use of psychoactive substances. Decreases in substance use may be because of decreased perceived availability and increased parental support and oversight. Interventions that focus on parental oversight and strengthened policies to disrupt the licit and illicit drug markets are needed.

Alcohol and cannabinoid binges and daily exposure to nicotine in adolescent/young adult rats induce sex-dependent long-term appetitive instrumental learning impairment

Adolescence is a critical developmental period, concerning anatomical, neurochemical and behavioral changes. Moreover, adolescents are more sensitive to the long-term deleterious effects of drug abuse. Binge-like consumption of alcohol and marijuana, along with tobacco smoking, is a dangerous pattern often observed in adolescents during weekends. Nevertheless, the long-term effect of their adolescent co-exposure has not been yet experimentally investigated. Long-Evans adolescent male (n = 20) and female (n = 20) rats from postnatal day 30 (P30) until P60 were daily treated with nicotine (0.3 mg/kg, i.p.), and, on two consecutive 'binging days' per week (for a total of eight times), received an intragastric ethanol solution (3 g/kg) and an intraperitoneal (i.p.) dose of cannabinoid 1/2 receptor agonist WIN55,212-2 (1.2 mg/kg). These rats were tested after treatment discontinuation at > P90 for associative food-rewarded operant learning in the two-lever conditioning chambers for six consecutive days on a fixed ratio 1 (FR1) schedule followed by another six days of daily FR2 schedule testing, after 42 days rest. We found the main effects of sex x treatment interactions in FR1 but not in FR2 experiments. Treated females show attenuated operant responses for food pellets during all FR1 and the FR2 schedule, whilst the treated males show an impairment in FR2 but not in the FR1 schedule. Moreover, the treated females' percentage of learners was significantly lower than female controls in FR1 while treated males were lower than controls in FR2. Our findings suggest that intermittent adolescent abuse of common drugs, such as alcohol and marijuana, and chronic tobacco exposure can cause significant long-term effects on motivation for natural reinforcers later in adulthood in both sexes. Females appear to be sensitive earlier to the deleterious effects of adolescent polydrug abuse, with both sexes having an increased likelihood of developing lifelong brain alterations.

Genetic influences impacting nicotine use and abuse during adolescence: Insights from human and rodent studies

Nicotine use continues to be a major public health concern, with an alarming recent rise in electronic cigarette consumption. Heritability estimates of nicotine use and abuse range from 40% to 80%, providing strong evidence that genetic factors impact nicotine addiction-relevant phenotypes. Although nicotine use during adolescence is a key factor in the development of addiction, it remains unclear how genetic factors impact adolescent nicotine use and abuse. This review will discuss studies investigating genetic factors impacting nicotine use during adolescence. Evidence from both rodent and human studies will be summarized and integrated when possible. Human adolescent studies have largely included candidate gene studies for genes identified in adult populations, such as genes involved in nicotine metabolism, nicotinic acetylcholine receptor signaling, dopaminergic signaling, and other neurotransmitter signaling systems. Alternatively, rodent studies have largely taken a discovery-based approach identifying strain differences in adolescent nicotine addiction-relevant behaviors. Here, we aim to answer the following three questions by integrating human and rodent findings: (1) Are there genetic variants that uniquely impact nicotine use during adolescence? (2) Are there genetic variants that impact both adolescent and adult nicotine use? and (3) Do genetic factors in adolescence significantly impact long-term consequences of adolescent nicotine use? Determining answers for these three questions will be critical for the development of preventative measures and treatments for adolescent nicotine use and addiction.

Dual Use of Nicotine and Cannabis Through Vaping Among Adolescents

INTRODUCTION

This study seeks to identify adolescent nicotine and cannabis vaping patterns and the characteristics of those adolescents who comprised each pattern.

METHODS

This prospective longitudinal survey study measured the relationship between nicotine and cannabis vaping among 1,835 adolescents from 4 public high schools outside of Philadelphia, Pennsylvania. Adolescents completed in-classroom surveys, including questions of lifetime and past 30-day nicotine and cannabis vaping, at Wave 1 (fall 2016, ninth grade) and 6-month intervals for the following 36 months (fall 2019, 12th grade). Data were analyzed in 2021.

RESULTS

A sequential processes growth mixture model revealed 4 latent conjoint classes of nicotine and cannabis vaping: early, declining dual use (Class 1: n=259); rapidly increasing dual use (Class 2: n=128); later, slower dual use (Class 3: n=313); and no use (Class 4: n=1,136). Increased odds of belonging to Class 1 and Class 2 versus belonging to Class 4 were significantly associated with cigarette smoking (OR=3.71, OR=2.21), alcohol use (OR=2.55, OR=4.39), peer vaping (OR=1.24, OR=1.20), sensation seeking (OR=1.03, OR=1.11), positive E-cigarette expectations (OR=1.21, OR=1.17), and cigar smoking (OR=2.39 Class 2 only). Increased odds of belonging to Class 3 versus Class 4 were significantly associated with alcohol use (OR=1.66), perceived benefits of E-cigarette use (OR=1.03), positive E-cigarette expectations (OR=1.08), depressive symptoms (OR=1.02), and sensation seeking (OR=1.03).

CONCLUSIONS

From middle to late adolescence, vaping of nicotine and cannabis develop in close parallel. Regulatory policy and prevention interventions should consider the interplay between these 2 substances during this period of adolescence.

Identifying alcohol misuse biotypes from neural connectivity markers and concurrent genetic associations

Alcohol use behaviors are highly heterogeneous, posing significant challenges to etiologic research of alcohol use disorder (AUD). Magnetic resonance imaging (MRI) provides intermediate endophenotypes in characterizing problem alcohol use and assessing the genetic architecture of addictive behavior. We used connectivity features derived from resting state functional MRI to subtype alcohol misuse (AM) behavior. With a machine learning pipeline of feature selection, dimension reduction, clustering, and classification we identified three AM biotypes-mild, comorbid, and moderate AM biotypes (MIA, COA, and MOA)-from a Human Connectome Project (HCP) discovery sample (194 drinkers). The three groups and controls (397 non-drinkers) demonstrated significant differences in alcohol use frequency during the heaviest 12-month drinking period (MOA > MIA; COA > non-drinkers) and were distinguished by connectivity features involving the frontal, parietal, subcortical and default mode networks. Further, COA relative to MIA, MOA and controls endorsed significantly higher scores in antisocial personality. A genetic association study identified that an alcohol use and antisocial behavior related variant rs16930842 from LINC01414 was significantly associated with COA. Using a replication HCP sample (28 drinkers and 46 non-drinkers), we found that subtyping helped in classifying AM from controls (area under the curve or AUC = 0.70, P < 0.005) in comparison to classifiers without subtyping (AUC = 0.60, not significant) and successfully reproduced the genetic association. Together, the results suggest functional connectivities as important features in classifying AM subgroups and the utility of reducing the heterogeneity in connectivity features among AM subgroups in advancing the research of etiological neural markers of AUD.

[Drinking behavior at the beginning and during the SARS-CoV-2 pandemic: results of a literature review]

Background and objective

It is well known that alcohol consumption and abuse, as well as alcohol-induced problems, increase during difficult economic times. Previous studies showed increased alcohol consumption in the 2003 SARS outbreak in China. The review examines global changes in alcohol consumption under current SARS-CoV‑2 (severe acute respiratory syndrome coronavirus 2) pandemic.

Materials and methods

The databases PubMed, Ovid, Cochrane Library, Scopus, PsycINFO, and Web of Science with a cut-off date of 11 January 2022 were used. An initial hit count of 791 publications was found. After reading the title and abstract, 62 texts were still eligible. After reviewing the full text, 40 studies were included in this review.

Results

Study results were available from North and South America, Europe, Asia and Oceania. Increases as well as reductions in alcohol consumption were shown. Studies examining multiple waves of the pandemic found that alcohol consumption increased with duration of the pandemic. Binge drinking played a large role in this. There were very large regional differences in the increase in alcohol consumption: from about 10% of respondents to > 45%. In most studies, alcohol consumption was about the same for 40-50% of respondents and decreased for 30-40%.

Conclusions

Further study follow-ups under the continuing pandemic are relevant. Since the populations studied were predominantly of working age, occupational prevention measures of elevated stress levels for some of the respondents with increased alcohol consumption seem reasonable.

Adolescent administration of Δ9-THC decreases the expression and function of muscarinic-1 receptors in prelimbic prefrontal cortical neurons of adult male mice

Long-term cannabis use during adolescence has deleterious effects in brain that are largely ascribed to the activation of cannabinoid-1 receptors (CB1Rs) by delta-9-tetrahydrocannabinol (∆9-THC), the primary psychoactive compound in marijuana. Systemic administration of ∆9-THC inhibits acetylcholine release in the prelimbic-prefrontal cortex (PL-PFC). In turn, PL-PFC acetylcholine plays a role in executive activities regulated by CB1R-targeting endocannabinoids, which are generated by cholinergic stimulation of muscarinic-1 receptors (M1Rs). However, the long-term effects of chronic administration of increasing doses of ∆9-THC in adolescent males on the distribution and function of M1 and/or CB1 receptors in the PL-PFC remains unresolved. We used C57BL\6J male mice pre-treated with vehicle or escalating daily doses of ∆9-THC to begin filling this gap. Electron microscopic immunolabeling showed M1R-immunogold particles on plasma membranes and in association with cytoplasmic membranes in varying sized dendrites and dendritic spines. These dendritic profiles received synaptic inputs from unlabeled, CB1R- and/or M1R-labeled axon terminals in the PL-PFC of both treatment groups. However, there was a size-dependent decrease in total (plasmalemmal and cytoplasmic) M1R gold particles in small dendrites within the PL-PFC of mice receiving ∆9-THC. Whole cell current-clamp recording in PL-PFC slice preparations further revealed that adolescent pretreatment with ∆9-THC attenuates the hyperpolarization and increases the firing rate produced by local muscarinic stimulation. Repeated administration of ∆9-THC during adolescence also reduced spontaneous alternations in a Y-maze paradigm designed for measures of PFC-dependent memory function in adult mice. Our results provide new information implicating M1Rs in cortical dysfunctions resulting from adolescent abuse of marijuana.

E-cigarette initiation predicts subsequent academic performance among youth: Results from the PATH Study

Research shows cigarette smoking is associated with lower academic performance among youth. This study examines how initiating e-cigarette use is associated with subsequent academic performance. Data from Waves 2-4 youth and parent surveys of the Population Assessment of Tobacco and Health (PATH) Study were analyzed. Youth (12-15 years old) who reported never using any tobacco products at Wave 2 were included in the analysis (n = 4960). Initiation of e-cigarettes and cigarettes was assessed at Wave 3. Weighted multivariable linear regression models were tested to assess the association between e-cigarette and cigarette initiation at Wave 3 and academic performance at Wave 4, controlling for covariates at Wave 2. At Wave 3, 4.3% and 1.9% of youth initiated e-cigarette and cigarette use, respectively. Youth who initiated e-cigarette use at Wave 3 had lower academic performance at Wave 4, compared to those who did not initiate e-cigarette use (adjusted regression coefficient [ARC] -0.22, 95% confidence interval [CI] -0.43, -0.02). Initiating cigarettes was also associated with lower academic performance (ARC -0.51, 95% CI -0.84, -0.18). Results indicate that e-cigarette use initiation is associated with lower subsequent academic performance, independent from the association between cigarette use initiation and lower academic performance among U.S. youth. Future research needs to examine whether preventing youth e-cigarette and cigarette use can lead to improvement in academic performance.

Healthy Lifestyle and Academic Performance in Middle School Students from the Region of Aragón (Spain)

A healthy lifestyle is important to the present and future development and health of school age people. This study aims to analyze the relationship between daily lifestyle habits and academic performance in a sample of adolescents from the autonomous community of Aragon (Spain). We performed a cross-sectional study to analyze the lifestyle habits and academic performance of a total of 1745 7th and 8th grade middle school students during the academic year 2018-2019; the participants were selected from a random sample of 43 middle schools from the region of Aragon. The following data were collected through an anonymized, previously validated questionnaire: diet, sleep, physical activity, use of screens, use of toxic substances, and academic performance. We found a statistically significant association between all the lifestyle habits analyzed and academic performance (p < 0.001) in our sample. Based on our findings, we suggest that health promotion and education in healthy lifestyles should be integrated in middle school curricula to improve academic performance and, more importantly, to promote both present and future health outcomes of adolescents.

Histamine H3 receptor and cholinesterases as synergistic targets for cognitive decline: Strategies to the rational design of multitarget ligands

The role of histamine and acetylcholine in cognitive functions suggests that compounds able to increase both histaminergic and cholinergic neurotransmissions in the brain should be considered as promising therapeutic options. For this purpose, dual inhibitors of histamine H₃ receptors (H₃ R) and cholinesterases (ChEs) have been designed and assessed. In this context, this paper reviews the strategies used to obtain dual H₃ R/ChEs ligands using multitarget design approaches. Hybrid compounds designed by linking tacrine or flavonoid motifs to H₃ R antagonists were obtained with high affinity for both targets, and compounds designed by merging the H₃ R antagonist pharmacophore with known anticholinesterase molecules were also reported. These reports strongly suggest that key modifications in the lipophilic region (including a second basic group) seem to be a strategy to reach novel compounds, allied with longer linker groups to a basic region. Some compounds have already demonstrated efficacy in memory models, although the pharmacokinetic and toxicity profile should be considered when designing further compounds. In conclusion, the key features to be considered when designing novel H₃ R/ChEs inhibitors with improved pharmacological profile were herein summarized.

Associations Between Family and Peer E-Cigarette Use With Adolescent Tobacco and Marijuana Usage: A Longitudinal Path Analytic Approach

INTRODUCTION

Research indicates a link between adolescent e-cigarette use and combustible tobacco cigarette (CTC) initiation, and recent studies suggest their connection with marijuana uptake. Our 3-year longitudinal cohort study investigated the implications of adolescent, peer, and family e-cigarette use with adolescents' expectations and willingness to initiate CTC use, and subsequent CTC and marijuana use.

AIMS AND METHODS

Relationships were examined in a secondary analysis of a 3-year longitudinal cohort subsample involving adolescents enrolled in alternative California high schools (N = 1025). Analyses examined responses over three yearly observations. Family, peer, and respondents' e-cigarette use, respondents' positive cigarette expectancies and willingness to use CTCs were assessed in the study's first year (T1). CTC use in the survey's second year (T2) and marijuana use in the third year (T3) were assessed via path analysis.

RESULTS

Respondents reporting at least one family member or peer using e-cigarettes were more likely to use e-cigarettes at T1 than those whose peers/family members did not. They reported more positive expectancies about CTCs and greater willingness to initiate use. These variables predicted CTC use at T2, which directly anticipated marijuana use in the survey's third year (T3), as did adolescents' use of e-cigarettes at T1. All model relations were statistically significant.

CONCLUSIONS

Analysis demonstrated the strong association of family members' and peers' behaviors with adolescent e-cigarette use, and the temporal precedence of e-cigarette use with subsequent CTC and marijuana uptake. The predictive implications of e-cigarettes for other dangerous substance use should be examined in future prevention campaigns.

IMPLICATIONS

The presented study expands upon existing literature connecting adolescent e-cigarette use and later CTC and marijuana use. The findings indicate the significant implications of exposure to e-cigarette use by parents and peers and demonstrate in a longitudinal 4-year panel survey the direct and indirect predictive implications of e-cigarette use for CTC and marijuana uptake. The research illustrates the utility of programs and campaigns that target peer and family groups to maximize impacts on adolescent willingness to try CTCs, positive expectancies, and possible onset of CTC and marijuana use.

Effects of Mephedrone and Amphetamine Exposure during Adolescence on Spatial Memory in Adulthood: Behavioral and Neurochemical Analysis

A synthetic cathinone, mephedrone is widely abused by adolescents and young adults. Despite its widespread use, little is known regarding its long-term effects on cognitive function. Therefore, we assessed, for the first time, whether (A) repeated mephedrone (30 mg/kg, i.p., 10 days, once a day) exposure during adolescence (PND 40) induces deleterious effects on spatial memory and reversal learning (Barnes maze task) in adult (PND 71-84) rats and whether (B) these effects were comparable to amphetamine (2.5 mg/kg, i.p.). Furthermore, the influence of these drugs on MMP-9, NMDA receptor subunits (GluN1, GluN2A/2B) and PSD-95 protein expression were assessed in adult rats. The drug effects were evaluated at doses that per se induce rewarding/reinforcing effects in rats. Our results showed deficits in spatial memory (delayed effect of amphetamine) and reversal learning in adult rats that received mephedrone/amphetamine in adolescence. However, the reversal learning impairment may actually have been due to spatial learning rather than cognitive flexibility impairments. Furthermore, mephedrone, but not amphetamine, enhanced with delayed onset, MMP-9 levels in the prefrontal cortex and the hippocampus. Mephedrone given during adolescence induced changes in MMP-9 level and up-regulation of the GluN2B-containing NMDA receptor (prefrontal cortex and hippocampus) in young adult (PND 63) and adult (PND 87) rats. Finally, in adult rats, PSD-95 expression was increased in the prefrontal cortex and decreased in the hippocampus. In contrast, in adult rats exposed to amphetamine in adolescence, GluN2A subunit and PSD-95 expression were decreased (down-regulated) in the hippocampus. Thus, in mephedrone-but not amphetamine-treated rats, the deleterious effects on spatial memory were associated with changes in MMP-9 level. Because the GluN2B-containing NMDA receptor dominates in adolescence, mephedrone seems to induce more harmful effects on cognition than amphetamine does during this period of life.

Intravenous self-administration of delta-9-THC in adolescent rats produces long-lasting alterations in behavior and receptor protein expression

RATIONALE

Initial exposure to cannabinoids, including Δ-9-tetrahydrocannabinol (THC), often occurs during adolescence. Considerable neurodevelopmental alterations occur throughout adolescence, and the environmental insult posed by exogenous cannabinoid exposure may alter natural developmental trajectories. Multiple studies suggest that long-lasting deficits in cognitive function occur as a result of adolescent cannabis use, but considerable variability exists in the magnitude of these effects.

OBJECTIVES

We sought to establish a novel procedure for achieving intravenous THC self-administration in adolescent rats in order to determine if volitional THC intake in adolescence produced indices of addiction-related behavior, altered working memory performance in adulthood, or altered the expression of proteins associated with these behaviors across several brain regions.

METHODS

Male and female adolescent rats learned to operantly self-administer escalating doses of THC intravenously from PD 32-51. Upon reaching adulthood they were tested in abstinence for cued reinstatement of THC-seeking and working memory performance on a delayed-match-to-sample task. In a separate cohort, glutamatergic, GABAergic, and cannabinoid receptor protein expression was measured in multiple brain regions.

RESULTS

Both male and female adolescents self-administered THC and exhibited cue-induced lever pressing throughout abstinence. THC-exposed males exhibited slightly enhanced working memory performance in adulthood, and better performance positively correlated with total THC self-administered during adolescence. Adolescent THC-exposed rats exhibited reductions in CB1, GABA, and glutamate receptor protein, primarily in the prefrontal cortex, dorsal hippocampus, and ventral tegmental area.

CONCLUSIONS

These results suggest that THC exposure at self-administered doses can produce moderate behavioral and molecular alterations, including sex-dependent effects on working memory performance in adulthood.

The effects of adolescent alcohol exposure on learning and related neurobiology in humans and rodents

Adolescent alcohol use is a widespread problem in the United States. In both humans and rodents, alcohol can impair learning and memory processes mediated by forebrain areas such as the prefrontal cortex (PFC) and hippocampus (HC). Adolescence is a period in which alcohol use often begins, and it is also a time that can be uniquely sensitive to the detrimental effects of alcohol. Exposure to alcohol during adolescence can cause persisting alterations in PFC and HC neurobiology that are linked to cognitive impairments, including changes in neurogenesis, inflammation, and various neurotransmitter systems in rodent models. Consistent with this, chronic adolescent alcohol exposure can cause PFC-dependent learning impairments that persist into adulthood. Deficits in adult HC-dependent learning after adolescent alcohol exposure have also been reported, but these findings are less consistent. Overall, evidence summarized in this review indicates that adolescent exposure to alcohol can produce long-term detrimental effects on forebrain-dependent cognitive processes.

Adolescent CB1 receptor antagonism influences subsequent social interactions and neural activity in female rats

We previously demonstrated that repeated exposure to the CB1 receptor antagonist/inverse agonist AM251 in adolescence (PND 30-44) increased social interactions in female rats when tested 48 h after the final exposure to the antagonist. Here, we investigated whether the increased sociality would be present after a longer drug washout period (5 days) in both male and female rats (experiment 1), and sought to identify candidate brain regions that may explain the observed differences in social behaviours between AM251 and vehicle-treated female rats (experiment 2). While drug-free, adolescent AM251 treatment increased social interactions in females and not in males. AM251 female rats had increased neural activity (as measured by the expression of early growth response protein-1; EGR-1) in the nucleus accumbens shell and cingulate gyrus of the medial prefrontal cortex, with no observed differences in EGR-1 expression in the dorsal hippocampus, nucleus accumbens core, or prelimbic and infralimbic subdivisions of the medial prefrontal cortex relative to vehicle rats. Together, these results demonstrate a sex-specific role of adolescent endocannabinoid signalling in the normative development of social behaviours and provide further support for adolescence as a vulnerable period for the effects of altered endocannabinoid signalling.

Adolescent Δ9-Tetrahydrocannabinol Exposure Selectively Impairs Working Memory but Not Several Other mPFC-Mediated Behaviors

As the frequency of cannabis use by 14-16-year-olds increases, it becomes increasingly important to understand the effect of cannabis on the developing central nervous system. Using mice as a model system, we treated adolescent (28 day old) C57BL6/J mice of both sexes for 3 weeks with 3 mg/kg tetrahydrocannabinol (THC). Starting a week after the last treatment, several cognitive behaviors were analyzed. Mice treated with THC as adolescents acquired proficiency in a working memory task more slowly than vehicle-treated mice. Working memory recall in both sexes of THC-treated mice was also deficient during increasing cognitive load compared to vehicle-treated mice. Our adolescent THC treatment did not strongly affect social preference, anxiety behaviors, or decision-making behaviors on the elevated T maze task. In summary, under the conditions of this study, adolescent THC treatment of mice markedly affected the establishment, and persistence of working memory, while having little effect on decision-making, social preference or anxiety behaviors. This study provides further support that adolescent THC affects specific behavioral domains.

The Protracted Maturation of Associative Layer IIIC Pyramidal Neurons in the Human Prefrontal Cortex During Childhood: A Major Role in Cognitive Development and Selective Alteration in Autism

The human specific cognitive shift starts around the age of 2 years with the onset of self-awareness, and continues with extraordinary increase in cognitive capacities during early childhood. Diffuse changes in functional connectivity in children aged 2-6 years indicate an increase in the capacity of cortical network. Interestingly, structural network complexity does not increase during this time and, thus, it is likely to be induced by selective maturation of a specific neuronal subclass. Here, we provide an overview of a subclass of cortico-cortical neurons, the associative layer IIIC pyramids of the human prefrontal cortex. Their local axonal collaterals are in control of the prefrontal cortico-cortical output, while their long projections modulate inter-areal processing. In this way, layer IIIC pyramids are the major integrative element of cortical processing, and changes in their connectivity patterns will affect global cortical functioning. Layer IIIC neurons have a unique pattern of dendritic maturation. In contrast to other classes of principal neurons, they undergo an additional phase of extensive dendritic growth during early childhood, and show characteristic molecular changes. Taken together, circuits associated with layer IIIC neurons have the most protracted period of developmental plasticity. This unique feature is advanced but also provides a window of opportunity for pathological events to disrupt normal formation of cognitive circuits involving layer IIIC neurons. In this manuscript, we discuss how disrupted dendritic and axonal maturation of layer IIIC neurons may lead into global cortical disconnectivity, affecting development of complex communication and social abilities. We also propose a model that developmentally dictated incorporation of layer IIIC neurons into maturing cortico-cortical circuits between 2 to 6 years will reveal a previous (perinatal) lesion affecting other classes of principal neurons. This "disclosure" of pre-existing functionally silent lesions of other neuronal classes induced by development of layer IIIC associative neurons, or their direct alteration, could be found in different forms of autism spectrum disorders. Understanding the gene-environment interaction in shaping cognitive microcircuitries may be fundamental for developing rehabilitation and prevention strategies in autism spectrum and other cognitive disorders.