Neurobiological signatures associated with alcohol and drug use in the human adolescent brain

ISRIB ameliorates spatial learning and memory impairment induced by adolescent intermittent ethanol exposure in adult male rats

Alcohol exposure in adolescence is considered a major cause of cognitive impairments later in life including spatial learning and memory. Integrated stress response (ISR), a program of conservative translation and transcription, is crucial in synaptic plasticity and memory. Although previous studies have elucidated ISR in different brain areas involved in learning and memory disorders, the impact of ISR on learning and memory following adolescent alcohol exposure remains unclear. Here, we demonstrated that adolescent intermittent ethanol (AIE) exposure caused spatial learning and memory impairment, combined with neuronal damage in the medial prefrontal cortex (mPFC), nucleus accumbens (NAc) and hippocampus (HIP) in adult rats. Moreover, integrated stress response inhibitor (ISRIB) administration not only improved spatial learning and memory impairment and neuronal damage but also inhibited the endoplasmic reticulum stress (ER) and reversed changes in synaptic proteins. These findings suggested that ISRIB ameliorates AIE exposure-induced spatial learning and memory deficits by improving neural morphology and synaptic function through inhibiting ER stress signaling pathway in the mPFC, NAc and HIP in adulthood. Our findings may enhance comprehension of cognitive function and neuronal effects of adolescent ethanol exposure and ISRIB treatment may be an underlying potential option for addressing alcohol-induced learning and memory deficits.

Therapeutic alliance in the treatment of adolescent substance misuse: a systematic review

BACKGROUND

Therapeutic alliance has been found to play an influential role in predicting outcomes for adults and adolescents in psychotherapy. However, thus far, the information concerning the impact of therapeutic alliance on outcomes for adolescents in treatment for substance misuse has not yet been critically synthesised.

METHODS

In accordance with PRISMA guidelines, the current review aimed to systematically collate published research investigating the association between alliance and outcomes for adolescents undergoing substance misuse treatment. Database searching produced 1083 records, with 16 studies meeting eligibility criteria.

RESULTS

Twelve out of the 16 studies (75%) reported significant alliance-outcome relationships, whereby higher alliance ratings predicted better treatment outcomes, as well as improved engagement and retention in treatment. In addition, the review explored the conditions whereby alliances better predict outcomes, with reference to the alliance rater, the timing of the alliance rating and comorbid diagnoses. These results, however, largely remain inconclusive.

CONCLUSIONS

The evidence as it stands demonstrates the importance of the therapeutic alliance in predicting outcomes for adolescents in substance misuse treatments. The implications of the review's findings and recommendations for future research are discussed.

Stress and substance use disorders: risk, relapse, and treatment outcomes

Stress has long been associated with substance misuse and substance use disorders (SUDs). The past two decades have seen a surge in research aimed at understanding the underlying mechanisms driving this association. This Review introduces a multilevel "adaptive stress response" framework, encompassing a stress baseline, acute reaction, and recovery with return-to-homeostasis phase that occurs at varying response times and across domains of analysis. It also discusses evidence showing the disruption of this adaptive stress response in the context of chronic and repeated stressors, trauma, adverse social and drug-related environments, as well as with acute and chronic drug misuse and with drug withdrawal and abstinence sequelae. Subjective, cognitive, peripheral, and neurobiological disruptions in the adaptive stress response phases and their link to inflexible, maladaptive coping; increased craving; relapse risk; and maintenance of drug intake are also presented. Finally, the prevention and treatment implications of targeting this "stress pathophysiology of addiction" are discussed, along with specific aspects that may be targeted in intervention development to rescue stress-related alterations in drug motivation and to improve SUD treatment outcomes.

Neurological Disorders Induced by Drug Use: Effects of Adolescent and Embryonic Drug Exposure on Behavioral Neurodevelopment

Clinical studies demonstrate that the risk of developing neurological disorders is increased by overconsumption of the commonly used drugs, alcohol, nicotine and cannabis. These drug-induced neurological disorders, which include substance use disorder (SUD) and its co-occurring emotional conditions such as anxiety and depression, are observed not only in adults but also with drug use during adolescence and after prenatal exposure to these drugs, and they are accompanied by long-lasting disturbances in brain development. This report provides overviews of clinical and preclinical studies, which confirm these adverse effects in adolescents and the offspring prenatally exposed to the drugs and include a more in-depth description of specific neuronal systems, their neurocircuitry and molecular mechanisms, affected by drug exposure and of specific techniques used to determine if these effects in the brain are causally related to the behavioral disturbances. With analysis of further studies, this review then addresses four specific questions that are important for fully understanding the impact that drug use in young individuals can have on future pregnancies and their offspring. Evidence demonstrates that the adverse effects on their brain and behavior can occur: (1) at low doses with short periods of drug exposure during pregnancy; (2) after pre-conception drug use by both females and males; (3) in subsequent generations following the initial drug exposure; and (4) in a sex-dependent manner, with drug use producing a greater risk in females than males of developing SUDs with emotional conditions and female offspring after prenatal drug exposure responding more adversely than male offspring. With the recent rise in drug use by adolescents and pregnant women that has occurred in association with the legalization of cannabis and increased availability of vaping tools, these conclusions from the clinical and preclinical literature are particularly alarming and underscore the urgent need to educate young women and men about the possible harmful effects of early drug use and to seek novel therapeutic strategies that might help to limit drug use in young individuals.

Factors associated with self-neglect from a salutogenic perspective among community-dwelling older adults: A cross-sectional correlational study

OBJECTIVES

To identify the associated factors of self-neglect in older adults from a salutogenic perspective.

METHODS

A cross-sectional correlational study was conducted in two communities in Beijing with 486 older adults recruited from April to December 2022. Data were collected by a set of questionnaires.

RESULTS

Sense of coherence (β=-0.138), socio-demographic generalized resistance resources (GRRs) (smoking: β=0.156), social GRRs (living alone: β=0.093), psychological GRRs (self-esteem: β=-0.126), and motivational GRRs (powerful others locus of control: β=-0.199, chance locus of control: β=0.119) were all associated with self-neglect among older adults (p<0.05).

CONCLUSIONS

Sense of coherence and GRRs are vital to improve self-neglect in older adults. It is suggested to increase the level of self-esteem and the tendency of the health locus of control to largely facilitate self-neglect management in older adults.

Burden of drug use disorders in the United States from 1990 to 2021 and its projection until 2035: results from the GBD study

BACKGROUND

Drug use disorders (DUDs) have emerged as one of the most significant public health crises, exerting a substantial influence on both community health and socio-economic progress. The United States (US) also suffers a heavy burden, it is necessary to figure out the situation from multiple perspectives and take effective measures to deal with it. Therefore, using the data from the Global Burden of Diseases, Injuries, and Risk Factors (GBD) 2021, we evaluated this topic.

METHODS

Annual data on DUDs-related burden were collected from the GBD study 2021. We calculated the indicator of estimated annual percentage change (EAPC) to evaluate the changing trend of burden. The Bayesian model for age-period-cohort was introduced to forecast the burden.

RESULTS

In 2021, the number and age-standardized rate of prevalence were particularly prominent, with 12,146.95 thousand and 3821.43 per 100,000, respectively. Higher burden was also observed in males, 15-45 years old populations, and opioid use disorders subtype. From 1990 to 2021, the DUDs-related burden increased in the US and all states, especially in West Virginia; and the national death-related burden with the highest increase (EAPC = 7.96). Other significant inverse associations were seen between EAPC, age-standardized rates, and socio-demographic index (SDI). Moreover, in the next 14 years, the projected DUDs burden remains exigent.

CONCLUSIONS

The burden of DUDs in the US is heavy and has been enlarging. This study proposes that greater attention should be paid to the strategies in males, the younger population, opioid use disorders, and low-SDI states implemented by decision-makers to achieve goals such as reducing burden.

Betting on Your Feelings: The Interplay between Emotion and Cognition in Gambling Affective Task

Background: Gambling Disorder (GD) is a bio-psycho-social disorder resulting from the interaction of clinical, cognitive, and affective factors. Impulsivity is a crucial factor in addiction studies, as it is closely linked to cognitive distortions in GD by encompassing impulsive choices, motor responses, decision-making, and cognitive biases. Also, emotions, mood, temperament, and affective state are crucial in developing and maintaining GD. Gambling can be used as a maladaptive coping strategy to avoid or escape problems and distress. Methods: The aim of the present study is to explore differences in personality traits and emotion regulation of people suffering from GD, substance-dependent gamblers (SDGs), and healthy controls (HCs). Additionally, the study proposes a new experimental task: the "Gambling Affective Task" (GAT) to investigate the influence of affective priming on risk-taking behaviors. Results: Our findings indicate that participants placed lower bets following positive priming. Additionally, SDGs wagered significantly higher amounts than HCs, regardless of priming type. In general, participants exhibited longer response times after positive priming trials, compared to negative and neutral priming trials. These findings suggest that experiencing positive emotions can act as a protective factor by delaying and lengthening gambling behaviors. By comparing gamblers with and without substance comorbidity, we can gain insight into the exclusive factors of GD and improve our understanding of this disorder. Conclusions: By elucidating the impact of emotional states on risk-taking, the research also provides new insights into the prevention and treatment of GD.

Concurrent and long-term effects of early pubertal timing on alcohol, cigarette, and cannabis use from adolescence to adulthood

OBJECTIVE

Early pubertal timing is a risk factor for substance use during adolescence. Fewer studies investigated whether early pubertal timing continues to predict substance use in late adolescence and adulthood, suggesting that long-term effects of pubertal timing vary across substances and by biological sex. Finally, existing studies on pubertal timing and substance use in adulthood involved predominantly White samples. Thus, this longitudinal study examined the concurrent and long-term effects of pubertal timing on alcohol, cigarette, and cannabis use together with sex differences in predominantly Black youth from the United States.

METHOD

The sample included 603 youth (52% male, 80% Black) who were interviewed in early adolescence (mean age: 13.2), late adolescence (mean age: 17.6), and young adulthood (mean age: 27.7). During early adolescence, youth self-reported their physical maturation based on Tanner scores, which were adjusted for age and used as indicators of pubertal timing. Youth self-reported their substance use at each time point.

RESULTS

Early pubertal timing was associated with higher odds of alcohol use during early adolescence but did not predict alcohol use during late adolescence or adulthood. While early pubertal timing did not predict cigarette use at any time point, early pubertal timing predicted greater odds for cannabis use during early adolescence and higher rates of cannabis use in adulthood. Moreover, early pubertal timing predicted greater risk for couse of alcohol, cigarettes, and cannabis in adulthood. No effects differed by sex.

CONCLUSIONS

These findings suggest that links between pubertal timing and substance use vary across substances and developmental periods. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Reconciling multiple sources of influence: Longitudinal associations among perceived parent, closest friend, and popular peer injunctive norms and adolescent substance use

Prospective associations over a 5-year period were examined among perceived parent, closest friend, and popular peer injunctive norms and the onset and frequency of adolescent substance use within a diverse (53% female, 45.5% White non-Hispanic, 22.3% Hispanic, 21.5% Black, 1% Asian, and 6.4% another race) sample of 868 seventh- and eighth-grade adolescents from 2012 to 2017. Analyses revealed adolescents' substance use norms were more lenient than perceptions of their parents' and stricter than perceptions of their closest friends'. Stricter perceptions of parent and closest friend norms, but not popular peer norms, were significantly associated with a later onset of alcohol, marijuana, and cigarette use, and the magnitude of the effect of each source' on later substance use varied across development.

Baseline brain and behavioral factors distinguish adolescent substance initiators and non-initiators at follow-up

Background

Earlier substance use (SU) initiation is associated with greater risk for the development of SU disorders (SUDs), while delays in SU initiation are associated with a diminished risk for SUDs. Thus, identifying brain and behavioral factors that are markers of enhanced risk for earlier SU has major public health import. Heightened reward-sensitivity and risk-taking are two factors that confer risk for earlier SU.

Materials and methods

We characterized neural and behavioral factors associated with reward-sensitivity and risk-taking in substance-naïve adolescents (N = 70; 11.1-14.0 years), examining whether these factors differed as a function of subsequent SU initiation at 18- and 36-months follow-up. Adolescents completed a reward-related decision-making task while undergoing functional MRI. Measures of reward sensitivity (Behavioral Inhibition System-Behavioral Approach System; BIS-BAS), impulsive decision-making (delay discounting task), and SUD risk [Drug Use Screening Inventory, Revised (DUSI-R)] were collected. These metrics were compared for youth who did [Substance Initiators (SI); n = 27] and did not [Substance Non-initiators (SN); n = 43] initiate SU at follow-up.

Results

While SI and SN youth showed similar task-based risk-taking behavior, SI youth showed more variable patterns of activation in left insular cortex during high-risk selections, and left anterior cingulate cortex in response to rewarded outcomes. Groups displayed similar discounting behavior. SI participants scored higher on the DUSI-R and the BAS sub-scale.

Conclusion

Activation patterns in the insula and anterior cingulate cortex may serve as a biomarker for earlier SU initiation. Importantly, these brain regions are implicated in the development and experience of SUDs, suggesting differences in these regions prior to substance exposure.

Signal in the noise: Altered brain activation among adolescent alcohol users detected via the analysis of intra-individual variability1

RATIONALE

Unlike its average level, the variability in brain activation over time or trials can capture subtle and brief disruptions likely to occur among participants with low-to-moderate levels of substance use or misuse.

OBJECTIVE

The present study used this intra-individual variability measurement approach to detect neural processing differences associated with light-to-moderate use of alcohol among 14-19-year-old adolescents.

METHOD

A total of 128 participants reporting any level of alcohol use during the previous 6 months and 87 participants reporting no use during this period completed intake questionnaires and interviews as well as an assessment of P300 electroencephalographic responses to novel stimuli recorded during two separate tasks.

RESULTS

In addition to differing in recent alcohol use, the groups differed in nicotine and cannabis use, risk-taking behavior and conduct disorder symptoms, and P300 amplitude inter-trial variability (ITV) across both tasks. Across all participants, P300 ITV was positively correlated with a family history of depression but not with a family history of alcohol dependence. There were no group differences in P300 amplitude averaged across trials.

CONCLUSIONS

Recent reports attributing brain volume or brain function differences to an effect of light-to-moderate alcohol use should be viewed with great caution. In the present analysis of brain function differences among substance-using adolescents, the group differences were small, complicated by many factors coinciding with or preceding alcohol use, and not reflected in a stable central tendency.

Effects of binge drinking during adolescence and emerging adulthood on the brain: A systematic review of neuroimaging studies

Binge drinking (BD) is a common pattern of alcohol consumption which is generating great concern because of its deleterious consequences. We selected 33 neuroimaging studies of healthy young binge drinkers (BDs) by following PRISMA guidelines. This review provides a comprehensive overview of the relationship between BD and neurocognitive anomalies reported across magnetic resonance studies. Moreover, this work is the first in which results of relatively new imaging techniques, such as resting-state functional connectivity (RS-FC) and neurite orientation dispersion and density imaging (NODDI), have been reviewed using a systematic procedure. We established strict inclusion criteria in order to isolate the various potential effects of BD on the adolescent brain. Two authors independently evaluated the methodological quality, assessing different aspects related to sample size, and statistical correction methods, which are of particular importance in neuroimaging studies. BD is associated with structural and functional anomalies in several cortical and subcortical brain regions intimately involved in the control and regulation of impulsive or risky behaviours, as well as in the processing of reinforcing stimuli.

Reduced structural connectivity of the amygdala is associated with childhood trauma in adult patients with alcohol use disorder

Childhood trauma (CT) is frequent in patients with alcohol use disorder (AUD) and may impact on adult drinking behaviour and treatment outcome. This study aimed to investigate the structural correlates of CT in AUD, focusing on the amygdala, which plays a crucial role in the neurobiology of trauma. We hypothesized reduced amygdala volume and reduced structural connectivity as quantified by fractional anisotropy (FA) and by number of streamlines in those AUD patients with a history of moderate to severe CT (AUD‐CT). T1‐weighted MP2RAGE and diffusion‐weighted imaging (DWI) 3‐Tesla MRI‐scans were acquired in 41 recently abstinent patients with AUD. We compared bilateral amygdala volume and structural connectivity (FA and number of streamlines) of pathways emanating from the amygdala between AUD‐CT (n = 20) and AUD without CT (AUD‐NT, n = 21) using a mixed model multivariate analysis of variance (MANCOVA) controlling for age and gender. AUD‐CT displayed reduced FA and reduced number of streamlines of amygdalar tracts. There were no differences regarding amygdala volume. The severity of physical abuse, a subscale of the childhood trauma questionnaire, was negatively correlated with FA and with number of streamlines. AUD‐CT and AUD‐NT differ regarding structural connectivity of pathways projecting to and from the amygdala, but not regarding amygdala volume. Those alterations of structural connectivity in AUD‐CT may represent a distinguishable neurobiological subtype of AUD, which might be associated with the complex clinical picture and poorer outcome that patients with CT and AUD often present.

Individual-, peer-, and parent-level substance use-related factors among 9- and 10-year-olds from the ABCD Study: Prevalence rates and sociodemographic differences

Background

Although a relatively large body of research has identified multiple factors associated with adolescent substance use, less is known about earlier substance-related factors during preadolescence, including curiosity to use substances. The present study examined individual-, peer-, and parent-level domains pertaining to substance use and how these domains vary by sociodemographic subgroups and substance type.

Methods

Participants were 11,864 9- and 10-year-olds from the baseline sample of the Adolescent Brain Cognitive Development (ABCD) Study. Youth-reported measures were curiosity to use substances and perceived peer substance use. Parent-reported measures were availability of and rules about substances. Generalized logistic mixed models (GLMM) were used to compare these measures across alcohol, nicotine, and marijuana and across sociodemographic subgroupings (sex, race/ethnicity, household income, and family history of alcohol problems). GLMM was then used to examine predictors of curiosity to use by substance type.

Results

The most striking descriptive differences were found between race/ethnicity and income categories (e.g., positive associations between greater income and greater availability of alcohol). In multivariable analyses, greater curiosity to use alcohol was associated with being male, higher household income, perceived peer alcohol use, and easy alcohol availability; greater curiosity to use nicotine was associated with being male, perceived peer cigarette use, easy availability of cigarettes, and no parental rules about cigarette use.

Conclusions

This study identified substance use-related individual-, peer-, and parent-level factors among a diverse, national sample. Findings highlight the importance of considering sociodemographic and substance-specific variability and may help identify risk and protective factors preceding adolescent substance use.

Alcohol use is associated with mental health problems and brain structural alterations in adolescents with perinatally acquired HIV infection on ART

Alcohol use, presents unique challenges for HIV-1 treatment in adolescents with perinatally acquired infection. The effects of alcohol on host-virus interaction in the brain and the immune system remains understudied in this population. Adolescents with perinatally acquired HIV infection (PHIV) well established on ART, from the Cape Town Adolescent Antiretroviral Cohort who self-reported alcohol use (PHIV + alcohol) (n = 26) were compared to age matched 26 PHIV (PHIV-alcohol) and 26 healthy controls (HC) who reported no use of alcohol. Participants completed clinical investigations including highly-sensitive CRP (hs-CRP), a comprehensive neurocognitive test battery and mental health measures. In addition, we investigated the relationship between alcohol use in PHIV and diffusion tensor imaging (DTI) and structural brain magnetic resonance imaging (MRI) to determine fractional anisotropy (FA), mean diffusivity (MD), grey and white matter volumes and cortical thickness. PHIV (mean age 12,5 years; mean age of ART initiation 3.15 years) reported an occasional weekend drinking pattern of alcohol use. hs-CRP was significantly different between groups, with PHIV + alcohol higher than PHIV-alcohol and HC. General intelligence, attention, working memory, processing speed and executive function were more impaired in the PHIV + alcohol than PHIV alone, with HC having the highest scores. In addition, self-concept was significantly lower in PHIV + alcohol. The Child Behavior Checklist (CBCL) Externalizing behaviour, internalising behaviour and CBCL Total problems were significantly higher in PHIV + alcohol. FA of the superior corona radiata, superior fronto-occipital fasciculus and corpus callosum was significantly lower in PHIV + alcohol compared to PHIV-alcohol and MD of the corona radiata was significantly increased in PHIV + alcohol. The cortical thickness of the lateral orbitofrontal, middle frontal and precentral gyri were significantly lower in PHIV + alcohol compared to PHIV-alcohol and HC. In conclusion PHIV associated impairments in systemic inflammation, cognitive function, mental health and changes in brain structure may be exacerbated by alcohol use, even if only occasional use. However, the study is cross-sectional, which is not able to distinguish between cause and effect.

Adolescent neuroimmune function and its interaction with alcohol

Adolescence is an evolutionarily conserved developmental period associated with behavioral change, including increased risk-taking and alcohol use. Experimentation with alcohol typically begins in adolescence and transitions to binge-like patterns of consumption. Alcohol exposure during adolescence can alter normative changes in brain structure and function. Understanding mechanisms by which ethanol impacts neurodevelopmental processes is important for preventing and ameliorating the deleterious consequences of adolescent alcohol abuse. This review focuses on the neuroimmune system as a key contributor to ethanol-induced changes in adolescent brain and behavior. After brief review of neuroimmune system development, acute and chronic effects of ethanol on adolescent neuroimmune functioning are addressed. Comparisons between stress/immunological challenges and ethanol on adolescent neuroimmunity are reviewed, as cross-sensitization is relevant during adolescence. The mechanisms by which ethanol alters neuroimmune functioning are then discussed, as they may portend development of neuropathological consequences and thus increase vulnerability to subsequent challenges and potentiate addictive behaviors.

Examining the Effectiveness of 3D Virtual Reality Training on Problem-solving, Self-efficacy, and Teamwork Among Inexperienced Volunteers Helping With Drug Use Prevention: Randomized Controlled Trial

BACKGROUND

Illegal drug usage among adolescents is a critical health problem. The Taiwanese government provides an accompanying volunteer program to prevent students who experiment with drugs from reusing them. An appropriate training program can improve volunteers' abilities to assist students using drugs. Problem-solving, self-efficacy, and teamwork are critical abilities for inexperienced volunteers who help with drug use prevention. By interacting with the animation or 3D virtual reality (VR) in the virtual scene, learners can immerse themselves in the virtual environment to learn, and 3D VR can increase learning opportunities and reduce the cost of human and material resources.

OBJECTIVE

The aim of this study was to examine the effectiveness of spherical video-based virtual reality (SVVR) training in improving problem-solving, self-efficacy, and teamwork among volunteers who helped prevent adolescents from using illegal drugs.

METHODS

This study used a randomized controlled design with a total of 68 participants in the experimental (n=35) and control (n=33) groups. The participants in the experimental group received the SVVR training program and their counterparts in the control group did not receive any training.

RESULTS

Generalized estimating equation analyses indicated that the experimental group showed significant posttraining improvements in problem-solving and self-efficacy but not teamwork when compared with the control group.

CONCLUSIONS

The results of this study revealed that SVVR could improve participants' problem-solving skills and self-efficacy for assisting students in not using illegal drugs. However, future studies are suggested to develop effective SVVR to assist inexperienced volunteers in enhancing their teamwork abilities. We believed that introducing the training program to more sites can enhance volunteer training so that volunteers can have a better companionship effect when helping students quit drugs.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05072431; https://clinicaltrials.gov/ct2/show/NCT05072431.

The persistent impact of adolescent binge alcohol on adult brain structural, cellular, and behavioral pathology: A role for the neuroimmune system and epigenetics

Adolescence is a critical neurodevelopmental window for maturation of brain structure, neurocircuitry, and glia. This development is sculpted by an individual's unique experiences and genetic background to establish adult level cognitive function and behavioral makeup. Alcohol abuse during adolescence is associated with an increased lifetime risk for developing an alcohol use disorder (AUD). Adolescents participate in heavy, episodic binge drinking that causes persistent changes in neurocircuitry and behavior. These changes may underlie the increased risk for AUD and might also promote cognitive deficits later in life. In this chapter, we have examined research on the persistent effects of adolescent binge-drinking both in humans and in rodent models. These studies implicate roles for neuroimmune signaling as well as epigenetic reprogramming of neurons and glia, which create a vulnerable neuroenvironment. Some of these changes are reversible, giving hope for future treatments to prevent many of the long-term consequences of adolescent alcohol abuse.

Primed for addiction: A critical review of the role of microglia in the neurodevelopmental consequences of adolescent alcohol drinking

Alcohol is one of the most widely used recreational substances worldwide, with drinking frequently initiated during adolescence. The developmental state of the adolescent brain makes it vulnerable to initiating alcohol use, often in high doses, and particularly susceptible to alcohol-induced brain changes. Microglia, the brain parenchymal macrophages, have been implicated in mediating some of these effects, though the role that these cells play in the progression from alcohol drinking to dependence remains unclear. Microglia are uniquely positioned to sense and respond to central nervous system insult, and are now understood to exhibit innate immune memory, or "priming," altering their future functional responses based on prior exposures. In alcohol use disorders (AUDs), the role of microglia is debated. Whereas microglial activation can be pathogenic, contributing to neuroinflammation, tissue damage, and behavioral changes, or protective, it can also engage protective functions, providing support and mediating the resolution of damage. Understanding the role of microglia in adolescent AUDs is complicated by the fact that microglia are thought to be involved in developmental processes such as synaptic refinement and myelination, which underlie the functional maturation of multiple brain systems in adolescence. Thus, the role microglia play in the impact of alcohol use in adolescence is likely multifaceted. Long-term sequelae may be due to a failure to recover from EtOH-induced tissue damage, altered neurodevelopmental trajectories, and/or persistent changes to microglial responsivity and function. Here, we review critically the literature surrounding the effects of alcohol on microglia in models of adolescent alcohol misuse. We attempt to disentangle what is known about microglia from other neuroimmune effectors, to which we apply recent discoveries on the role of microglia in development and plasticity. Considered altogether, these studies challenge assumptions that proinflammatory microglia drive addiction. Alcohol priming microglia and thereby perturbing their homeostatic roles in neurodevelopment, especially during critical periods of plasticity such as adolescence, may have more serious implications for the neuropathogenesis of AUDs in adolescents.

Adolescent Ethanol Exposure Alters Cholinergic Function and Apical Dendritic Branching Within the Orbital Frontal Cortex

During adolescence, heavy binge-like ethanol consumption can lead to frontocortical structural and functional impairments. These impairments are likely driven by adolescence being a critical time point for maturation of brain regions associated with higher-order cognitive functioning. Rodent models of heavy binge-like ethanol exposure show consistent disruptions to the typical development of the prefrontal cortex (PFC). All deep cortical layers receive cholinergic projections that originate from the Nucleus basalis of Meynert (NbM) complex. These cholinergic projections are highly involved in learning, memory, and attention. Adolescent intermittent ethanol exposure (AIE) induces cholinergic dysfunction as a result of an epigenetic suppression of the genes that drive the cholinergic phenotype. The current study used a model of AIE to assess structural and functional changes to the frontal cortex and NbM following binge-like ethanol exposure in adolescence. Western blot analysis revealed long-term disruptions of the cholinergic circuit following AIE: choline acetyltransferase (ChAT) was suppressed in the NbM and vesicular acetylcholine transporter (VAChT) was suppressed in the orbitofrontal cortex (OFC). In vivo microdialysis for acetylcholine efflux during a spatial memory task determined changes in cholinergic modulation within the PFC following AIE. However, AIE spared performance on the spatial memory task and on an operant reversal task. In a second study, Golgi-Cox staining determined that AIE increased apical dendritic complexity in the OFC, with sex influencing whether the increase in branching occurred near or away from the soma. Spine density or maturity was not affected, likely compensating for a disruption in neurotransmitter function following AIE.

Age-Related Variations in Regional White Matter Volumetry and Microstructure During the Post-adolescence Period: A Cross-Sectional Study of a Cohort of 1,713 University Students

Human brain white matter undergoes a protracted maturation that continues well into adulthood. Recent advances in diffusion-weighted imaging (DWI) methods allow detailed characterizations of the microstructural architecture of white matter, and they are increasingly utilized to study white matter changes during development and aging. However, relatively little is known about the late maturational changes in the microstructural architecture of white matter during post-adolescence. Here we report on regional changes in white matter volume and microstructure in young adults undergoing university-level education. As part of the MRi-Share multi-modal brain MRI database, multi-shell, high angular resolution DWI data were acquired in a unique sample of 1,713 university students aged 18-26. We assessed the age and sex dependence of diffusion metrics derived from diffusion tensor imaging (DTI) and neurite orientation dispersion and density imaging (NODDI) in the white matter regions as defined in the John Hopkins University (JHU) white matter labels atlas. We demonstrate that while regional white matter volume is relatively stable over the age range of our sample, the white matter microstructural properties show clear age-related variations. Globally, it is characterized by a robust increase in neurite density index (NDI), and to a lesser extent, orientation dispersion index (ODI). These changes are accompanied by a decrease in diffusivity. In contrast, there is minimal age-related variation in fractional anisotropy. There are regional variations in these microstructural changes: some tracts, most notably cingulum bundles, show a strong age-related increase in NDI coupled with decreases in radial and mean diffusivity, while others, mainly cortico-spinal projection tracts, primarily show an ODI increase and axial diffusivity decrease. These age-related variations are not different between males and females, but males show higher NDI and ODI and lower diffusivity than females across many tracts. These findings emphasize the complexity of changes in white matter structure occurring in this critical period of late maturation in early adulthood.

Alcohol and Brain Development in Adolescents and Young Adults: A Systematic Review of the Literature and Advisory Report of the Health Council of the Netherlands

Young people, whose brains are still developing, might entail a greater vulnerability to the effects of alcohol consumption on brain function and development. A committee of experts of the Health Council of the Netherlands evaluated the state of scientific knowledge regarding the question whether alcohol negatively influences brain development in young people. A systematic literature search for prospective studies was performed in PubMed and PsychINFO, for longitudinal studies of adolescents or young adults ranging between 12 and 24 y of age at baseline, investigating the relation between alcohol use and outcome measures of brain structure and activity, cognitive functioning, educational achievement, or alcohol use disorder (AUD), with measures at baseline and follow-up of the outcome of interest. Data were extracted from original articles and study quality was assessed using the Newcastle-Ottawa Scale. A total of 77 studies were included, 31 of which were of sufficient quality in relation to the study objectives. There were indications that the gray matter of the brain develops abnormally in young people who drink alcohol. In addition, the more often young people drink or the younger they start, the higher the risk of developing AUD later in life. The evidence on white matter volume or quality, brain activity, cognitive function, and educational achievement is still limited or unclear. The committee found indications that alcohol consumption can have a negative effect on brain development in adolescents and young adults and entails a risk of later AUD. The committee therefore considers it a wise choice for adolescents and young adults not to drink alcohol.

Examining the differential effects of latent impulsivity factors on substance use outcomes in African American men

African Americans have elevated substance use-related problems during adulthood despite initiating use later than individuals of other racial/ethnic backgrounds. The present study first validated the structure of the UPPS-P Impulsive Behavior Scale and then examined impulsivity as a prospective risk factor for future alcohol, cannabis, and tobacco use, as well as generalized substance problems, in African American men. Data were drawn from the African-American Men's Project, which recruited participants (N_WAVE-1 = 504; Mean age_WAVE-1 = 20.7; N_WAVE-3 = 379; Mean age_WAVE-3 = 23.6) from rural counties of Georgia. Participants responded to an adapted version of the UPPS-P at Wave 1. Confirmatory factor analyses determined that a 5-factor model of impulsivity and a 3-factor hierarchical model of impulsivity described the data equally well, in comparison to 1-factor, 4-factor, or bifactor models. This supports that the structure of the abbreviated UPPS-P in African Americans is likely consistent with observations in White, Hispanic/Latino, and admixed samples. Notably, all second-order factors of the UPPS-P are not alike in predicting substance use outcomes when examined jointly in African American men. Only Deficits in Conscientiousness, which is a second-order factor comprised of Lack of Premeditation and Lack of Perseverance, affected whether individuals met any criteria for future substance use problems. Our findings provide novel insight into the relationship between impulsivity and substance involvement during emerging adulthood in African American men.

Association of Heavy Drinking With Deviant Fiber Tract Development in Frontal Brain Systems in Adolescents

IMPORTANCE

Maturation of white matter fiber systems subserves cognitive, behavioral, emotional, and motor development during adolescence. Hazardous drinking during this active neurodevelopmental period may alter the trajectory of white matter microstructural development, potentially increasing risk for developing alcohol-related dysfunction and alcohol use disorder in adulthood.

OBJECTIVE

To identify disrupted adolescent microstructural brain development linked to drinking onset and to assess whether the disruption is more pronounced in younger rather than older adolescents.

DESIGN, SETTING, AND PARTICIPANTS

This case-control study, conducted from January 13, 2013, to January 15, 2019, consisted of an analysis of 451 participants from the National Consortium on Alcohol and Neurodevelopment in Adolescence cohort. Participants were aged 12 to 21 years at baseline and had at least 2 usable magnetic resonance diffusion tensor imaging (DTI) scans and up to 5 examination visits spanning 4 years. Participants with a youth-adjusted Cahalan score of 0 were labeled as no-to-low drinkers; those with a score of greater than 1 for at least 2 consecutive visits were labeled as heavy drinkers. Exploratory analysis was conducted between no-to-low and heavy drinkers. A between-group analysis was conducted between age- and sex-matched youths, and a within-participant analysis was performed before and after drinking.

EXPOSURES

Self-reported alcohol consumption in the past year summarized by categorical drinking levels.

MAIN OUTCOMES AND MEASURES

Diffusion tensor imaging measurement of fractional anisotropy (FA) in the whole brain and fiber systems quantifying the developmental change of each participant as a slope.

RESULTS

Analysis of whole-brain FA of 451 adolescents included 291 (64.5%) no-to-low drinkers and 160 (35.5%) heavy drinkers who indicated the potential for a deleterious association of alcohol with microstructural development. Among the no-to-low drinkers, 142 (48.4%) were boys with mean (SD) age of 16.5 (2.2) years and 149 (51.2%) were girls with mean (SD) age of 16.5 (2.1) years and 192 (66.0%) were White participants. Among the heavy drinkers, 86 (53.8%) were boys with mean (SD) age of 20.1 (1.5) years and 74 (46.3%) were girls with mean (SD) age of 20.5 (2.0) years and 142 (88.8%) were White participants. A group analysis revealed FA reduction in heavy-drinking youth compared with age- and sex-matched controls (t154 = -2.7, P = .008). The slope of this reduction correlated with log of days of drinking since the baseline visit (r156 = -0.21, 2-tailed P = .008). A within-participant analysis contrasting developmental trajectories of youths before and after they initiated heavy drinking supported the prediction that drinking onset was associated with and potentially preceded disrupted white matter integrity. Age-alcohol interactions (t152 = 3.0, P = .004) observed for the FA slopes indicated that the alcohol-associated disruption was greater in younger than older adolescents and was most pronounced in the genu and body of the corpus callosum, regions known to continue developing throughout adolescence.

CONCLUSIONS AND RELEVANCE

This case-control study of adolescents found a deleterious association of alcohol use with white matter microstructural integrity. These findings support the concept of heightened vulnerability to environmental agents, including alcohol, associated with attenuated development of major white matter tracts in early adolescence.

Alcohol Consumption among Freshman College Students in Spain: Individual and Pooled Analyses of Three Cross-Sectional Surveys (2005, 2012 and 2016)

Objective: We aimed to evaluate changes in the prevalence of Heavy Episodic Drinking (HED) and Risky Consumption (RC) in freshman college students between 2005, 2012 and 2016; and to identify the explanatory variables of these patterns of consumption using individual and pooled analyses. Methods: A cross-sectional study involving 5260 students was carried out in Spain in 2005, 2012 and 2016. HED and RC were determined using the Alcohol Use Disorders Identification Test. Another questionnaire was used to measure parental education level and alcohol use, alcohol-related problems, age of onset of alcohol use and alcohol-related expectancies. Adjusted Odds Ratios (ORs) of RC and HED and their 95% Confidence Intervals were estimated using logistic regression. Results: An increase in the prevalence rates of HED and RC was observed among women during the three-study periods, nonetheless there was no statistically significant difference in the prevalence rates among men. High maternal educational level, living away from parental home, initiating drinking before the age of 15 and having positive expectancies about drinking are associated with higher prevalence of RC in both genders. High positive expectancies and early onset of alcohol use are associated with higher rates of HED among men and women. Students recruited in 2012 and 2016 are protected against RC in comparison to those recruited in 2005. Conclusions: The age of alcohol consumption onset is the most influencing factor on HED and RC for both genders in the three-study periods. Alcohol prevention campaigns targeting youth at early ages can reduce risky drinking behaviors.

Volumetric trajectories of hippocampal subfields and amygdala nuclei influenced by adolescent alcohol use and lifetime trauma

Alcohol use and exposure to psychological trauma frequently co-occur in adolescence and share many risk factors. Both exposures have deleterious effects on the brain during this sensitive developmental period, particularly on the hippocampus and amygdala. However, very little is known about the individual and interactive effects of trauma and alcohol exposure and their specific effects on functionally distinct substructures within the adolescent hippocampus and amygdala. Adolescents from a large longitudinal sample (N = 803, 2684 scans, 51% female, and 75% White/Caucasian) ranging in age from 12 to 21 years were interviewed about exposure to traumatic events at their baseline evaluation. Assessments for alcohol use and structural magnetic resonance imaging scans were completed at baseline and repeated annually to examine neurodevelopmental trajectories. Hippocampal and amygdala subregions were segmented using Freesurfer v6.0 tools, followed by volumetric analysis with generalized additive mixed models. Longitudinal statistical models examined the effects of cumulative lifetime trauma measured at baseline and alcohol use measured annually on trajectories of hippocampal and amygdala subregions, while controlling for covariates known to impact brain development. Greater alcohol use, quantified using the Cahalan scale and measured annually, was associated with smaller whole hippocampus (β = -12.0, p_FDR = 0.009) and left hippocampus tail volumes (β = -1.2, p_FDR = 0.048), and larger right CA3 head (β = 0.4, p_FDR = 0.027) and left subiculum (β = 0.7, p_FDR = 0.046) volumes of the hippocampus. In the amygdala, greater alcohol use was associated with larger right basal nucleus volume (β = 1.3, p_FDR = 0.040). The effect of traumatic life events measured at baseline was associated with larger right CA3 head volume (β = 1.3, p_FDR = 0.041) in the hippocampus. We observed an interaction between baseline trauma and within-person age change where younger adolescents with greater trauma exposure at baseline had smaller left hippocampal subfield volumes in the subiculum (β = 0.3, p_FDR = 0.029) and molecular layer HP head (β = 0.3, p_FDR = 0.041). The interaction also revealed that older adolescents with greater trauma exposure at baseline had larger right amygdala nucleus volume in the paralaminar nucleus (β = 0.1, p_FDR = 0.045), yet smaller whole amygdala volume overall (β = -3.7, p_FDR = 0.003). Lastly, we observed an interaction between alcohol use and baseline trauma such that adolescents who reported greater alcohol use with greater baseline trauma showed smaller right hippocampal subfield volumes in the CA1 head (β = -1.1, p_FDR = 0.011) and hippocampal head (β = -2.6, p_FDR = 0.025), yet larger whole hippocampus volume overall (β = 10.0, p_FDR = 0.032). Cumulative lifetime trauma measured at baseline and alcohol use measured annually interact to affect the volume and trajectory of hippocampal and amygdala substructures (measured via structural MRI annually), regions that are essential for emotion regulation and memory. Our findings demonstrate the value of examining these substructures and support the hypothesis that the amygdala and hippocampus are not homogeneous brain regions.

Altered resting functional connectivity patterns associated with problematic substance use and substance use disorders during adolescence

BACKGROUND

Adolescence is typified by increasing rates of substance use and the development of substance use disorders (SUD). Aberrant connectivity between cortical regions involved in executive control, and subcortical regions has been suggested to be associated with SUD and problematic substance use among adolescents. Few studies, however, have investigated system-level or whole-brain functional connectivity (FC) in order to test this hypothesis.

METHODS

In a sample of 114 adolescents (mean age = 17.62 years, SD = 1.23, 61F) from the community, the present study used resting-state functional magnetic resonance imaging and independent component analysis to study executive control-subcortical network (ECN-SCN) coupling in adolescent SUD (n=18) and problematic substance use (n=34). In addition, whole-brain FC analyses were also conducted.

RESULTS

Problematic substance use, but not SUD, was associated with increased negative ECN-SCN coupling (p = 0.026). The whole-brain FC analysis showed insula-associated hypoconnectivity in the SUD group (p = 0.037), which was negatively correlated with frequency of substance use.

CONCLUSIONS

Findings implicate different neural circuitry underlying adolescent SUD versus problematic use. Greater negative coupling between the SCN and ECN in adolescents with problematic substance use could underlie risk for future development of SUD or other mental health problems. Although we cannot infer directionality, hypoconnectivity within the insula in adolescents with SUD may indicate addiction-related alterations in interoceptive awareness or impairments in decision-making.

Alcohol Use Disorder and Cannabis Use Disorder Symptomatology in Adolescents and Aggression: Associations With Recruitment of Neural Regions Implicated in Retaliation

BACKGROUND

Alcohol and cannabis are commonly used by adolescents in the United States. Both alcohol use disorder (AUD) and cannabis use disorder (CUD) have been associated with an increased risk of aggression. One form of aggression seen during retaliation is reactive aggression to social provocation. This study investigated the association between AUD and CUD symptom severity and recruitment of neural regions implicated in retaliation.

METHODS

In this study, 102 youths aged 13-18 years (67 male; 84 in residential care) completed self-report measures of aggression-related constructs and participated in a retaliation task during functional magnetic resonance imaging to investigate the association between relative severity of AUD/CUD and atypical recruitment of regions implicated in retaliation.

RESULTS

AUD Identification Test scores were positively associated with irritability and reactive aggression scores. CUD Identification Test scores were positively associated with callous-unemotional traits and both proactive and reactive aggression scores. In functional magnetic resonance imaging analyses, only AUD Identification Test (not CUD Identification Test) scores were associated with an exaggerated recruitment of regions implicated in retaliation (dorsomedial frontal, anterior insula cortices, caudate, and, to a lesser extent, periaqueductal gray).

CONCLUSIONS

These data suggest that relative severity of AUD is associated with a disinhibited, exaggerated retaliation response that relates to an increased risk for reactive aggression. Similar findings were not related to severity of CUD.

Substances use and its association with socio-demographic, family, and environment-related factors among technical and vocational education and training college students in Ataye, Ethiopia; an institution-based cross-sectional study

Background

Legal substances use is prevalent in Ethiopia. Substance use can have several health problems that are potentially harmful to educational performance, social issues, psychological and physical wellbeing. This study aimed to know the prevalence of lifetime and last month’s substance use and its associated factors among technical and vocational education and training College students in Ataye town.

Methods

An institution-based cross-sectional study was conducted from 1 March to last May 2019. Participants were selected using a simple random sampling technique. Data collected by using a structured and pretested interviewer-administered questionnaire. Data collected by five trained diploma nurses with close supervision. Odds ratio with their 95% confidence interval, and p-value less than 0.05 used to declare the statistical significance of associated factors.

Results

Four hundred eighty-three individuals participated in the study, which was a response rate of 94%. The prevalence of lifetime legal substance use was 32.5% (95% CI: 28.2, 36.5). The prevalence of last month’s legal substances use was 21.9% (95% CI = 18.2, 25.5). Among lifetime legal substance users, the majority (25.5%) chewed khat. The others, (19.5%) drunk alcohol, and, 15.3% smoked cigarettes in a lifetime. Lifetime cannabis and cocaine users were 2.5, and 7.2% respectively. Among last month’s legal substance users, (21.9%) chewed khat followed by alcohol drinking (16.6%), and cigarette smoking (15.3%). In the last month, 1.2 and 3.3% of students used cannabis and cocaine respectively. Multivariate logistic regression showed that being male, having a divorced family, living greater than 20 years in the town, having substance user family members, having intimate friend substance users, and easy availability of substances were independent predictors of lifetime legal substances use.

Conclusions

The prevalence of last month and lifetime legal substance use at Ataye Technical and Vocational Education and Training (TVET) college students were analogous with most studies done in Ethiopia. It is advisable if the college administrators work together with town administrators to mitigate the problem including closing substance use houses around the school. Overall, Substance use among adolescents should get further emphasis to lower the prevalence.

Trends in the psychosocial characteristics of 11-15-year-olds who still drink, smoke, take drugs and engage in poly-substance use in England

INTRODUCTION AND AIMS

Youth substance use is declining in many high-income countries. As adolescent substance use becomes less common, it may concentrate in higher-risk groups. This paper aims to examine how the psychosocial characteristics of young substance users in England have changed over time.

DESIGN AND METHODS

Annual cross-sectional data from the 2001-2014 Smoking, Drinking and Drug Use Among Young People in England survey are analysed (n = 112 792, age: 11-15). Logistic and Poisson regression analyses are used to test whether the sex, socioeconomic status (SES) and prevalence of truancy and exclusion from school of those who drink alcohol, smoke cigarettes, take cannabis, take other drugs and engage in poly-substance use changed across the study period.

RESULTS

Use of all substances decreased and there were shifts in the psychosocial characteristics of young smokers, illicit drug users and poly-substance users. The proportion of current smokers and ever-users of cannabis of low SES and who had been excluded increased significantly between 2001/2003-2014. The proportion of last month drug users who had been excluded from school also increased significantly and there were increases in the proportion of polysubstance-users who had truanted and been excluded. The proportion of low SES alcohol users who had been excluded also increased significantly, but this change was very small. There was no evidence of substance use becoming more or less concentrated in one gender.

DISCUSSION AND CONCLUSIONS

There is some evidence that smoking, illicit drug use and poly-substance use are becoming more concentrated in potentially at risk populations. There is limited evidence of concentration amongst young drinkers.

Parsing inter- and intra-individual variability in key nervous system mechanisms of stress responsivity and across functional domains

Exposure to stressful events is omnipresent in modern human life, yet people show considerable heterogeneity in the impact of stress exposure(s) on their functionality and overall health. Encounter with stressor(s) is counteracted by an intricate repertoire of nervous-system responses. This narrative review starts with a brief summary of the vast evidence that supports heart rate variability, cortisol secretion, and large-scale cortical network interactions as kay physiological, endocrinological, and neural mechanisms of stress responsivity, respectively. The second section highlights potential sources for inter-individual variability in these mechanisms, by focusing on biological, environmental, social, habitual, and psychological factors that may influence stress responsivity patterns and thus contribute to heterogeneity in the impact of stress exposure on functionality and health. The third section introduces intra-individually variability in stress responsivity across functional domains as a novel putative source for heterogeneity in the impact of stress exposure. Challenges and future directions are further discussed. Parsing inter- and intra-individual variability in nervous-system mechanisms of stress responsivity and across functional domains is critical towards potential clinical translation.

Cannabis and Illicit Drug Use During Neurodevelopment and the Associated Structural, Functional and Cognitive Outcomes: Protocol for a Systematic Review

Background

High rates of cannabis and illicit drug use are experienced by young people during the final stages of neurodevelopment (aged 15-24 years), a period characterized by high neuroplasticity. Frequent drug use during this time may interfere with neurophysiological and neuropsychological development pathways, potentially leading to ongoing unfavorable neuroadaptations. The dose-response relationship between illicit drug use, exposure, and individual neurodevelopmental variation is unknown but salient with global shifts in the legal landscape and increasingly liberal attitudes and perceptions of the harm caused by cannabis and illicit drugs.

Objective

This systematic review aims to synthesize longitudinal studies that investigate the effects of illicit drug use on structural, functional, and cognitive brain domains in individuals under the neural age of adulthood (25 years). This protocol outlines prospective methods that will facilitate an exhaustive review of the literature exploring pre- and post-drug use brain abnormalities arising during neurodevelopment.

Methods

Five electronic databases (Medline, Embase, PsycINFO, ProQuest Central, and Web of Science) will be systematically searched between 1990 and 2019. The search terms will be a combination of MeSH (Medical Subject Headings), with keywords adapted to each database. Study reporting will follow the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, and if relevant, study quality will be assessed using the Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) approach. Eligible studies are those that sampled youth exposed to cannabis or illicit drugs and employed neurophysiological or neuropsychological assessment techniques. Studies will be excluded if participants had been clinically diagnosed with any psychiatric, neurological, or pharmacological condition.

Results

This is an ongoing review. As of February 2020, papers are in full-text screening, with results predicted to be complete by July 2020.

Conclusions

Integrating data collected on the three brain domains will enable an assessment of the links between structural, functional, and cognitive brain health across individuals and may support the early detection and prevention of neurodevelopmental harm.

Trial Registration

PROSPERO CRD42020151442; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=151442

International Registered Report Identifier (IRRID)

PRR1-10.2196/18349

Heavy drinking in adolescents is associated with change in brainstem microstructure and reward sensitivity

Heavy drinker adolescents: altered brainstem microstructure.

Disturbed Cerebellar Growth Trajectories in Adolescents Who Initiate Alcohol Drinking

BACKGROUND

The cerebellum is a target of alcoholism-related brain damage in adults, yet no study has prospectively tracked deviations from normal cerebellar growth trajectories in adolescents before and after initiating drinking.

METHODS

Magnetic resonance imaging tracked developmental volume trajectories of 10 cerebellar lobule and vermis tissue constituents in 548 no/low drinking youths age 12 to 21 years at induction into this 5-site, NCANDA (National Consortium on Alcohol and NeuroDevelopment in Adolescence) study. Over the 3- to 4-year longitudinal examination yielding 2043 magnetic resonance imaging scans, 328 youths remained no/low drinkers, whereas 220 initiated substantial drinking after initial neuroimaging.

RESULTS

Normal growth trajectories derived from no/low drinkers indicated that gray matter volumes of lobules V and VI, crus II, lobule VIIB, and lobule X declined faster with age in male youths than in female youths, whereas white matter volumes in crus I and crus II and lobules VIIIA and VIIIB expanded faster in female youths than in male youths; cerebrospinal fluid volume expanded faster in most cerebellar regions of male youths than female youths. Drinkers exhibited accelerated gray matter decline in anterior lobules and vermis, accelerated vermian white matter expansion, and accelerated cerebrospinal fluid volumes expansion of anterior lobules relative to youths who remained no/low drinkers. Analyses including both alcohol and marijuana did not support an independent role for marijuana in alcohol effects on cerebellar gray matter trajectories.

CONCLUSIONS

Alcohol use-related cerebellar growth trajectory differences from normal involved anterior lobules and vermis of youths who initiated substantial drinking. These regions are commonly affected in alcohol-dependent adults, raising the possibility that cerebellar structures affected by youthful drinking may be vulnerable to age-alcohol interactions in later adulthood.

Emotional memory bias in binge drinking women

BACKGROUND

Heightened emotionality and overrepresentation of memories are typical features of adolescence. Binge drinking (BD) during emerging adulthood has been linked to cognitive difficulties such as deficits in episodic memory. Despite that impairments in emotional functioning have been associated with the development of alcohol use disorders, particularly in females, the emotional sphere has been relatively unexplored in BDs. Therefore, the purpose of this study is to examine the effects of BD in emotional episodic memory from a gender perspective.

METHODS

One hundred and eighty (96 females) university students were followed during two years (18-20 years old) and their alcohol use was recorded. In the last assessment, participants completed an emotional list-learning task. Generalized linear mixed models were applied separately for males and females, in accordance with sex differences in the development of emotion circuitry.

RESULTS

In females, BD was associated with an emotional memory bias in favour of negative information and lower recall of positive and neutral words. In addition, females BDs showed more false alarms for negative distractors. Whereas in males, no alcohol-related effects were found.

CONCLUSIONS

Female BDs present a negative memory bias, poor learning and delayed episodic recall linked to the interference of negative content, which suggests difficulties in disengaging attention to salient negative stimuli and a reduction of inhibitory capacities. This might result in greater vulnerability to alcohol-related emotional disturbances among women. Further research is needed to understand the role of emotional regulation in the escalation of alcohol abuse from a gender perspective.

Adolescent Ethanol Exposure: Anxiety-Like Behavioral Alterations, Ethanol Intake, and Sensitivity

Adolescence is a developmental period associated with rapid age-specific physiological, neural, and hormonal changes. Behaviorally, human adolescents are characterized by age-typical increases in novelty-seeking and risk-taking, including the frequent initiation of alcohol and drug use. Alcohol use typically begins during early adolescence, and older adolescents often report high levels of alcohol consumption, commonly referred to as high-intensity drinking. Early-onset and heavy drinking during adolescence are associated with an increased risk of developing alcohol use disorders later in life. Yet, long-term behavioral consequences of adolescent alcohol use that might contribute to excessive drinking in adulthood are still not well understood. Recent animal research, however, using different exposure regimens and routes of ethanol administration, has made substantial progress in identifying the consequences of adolescent ethanol exposure that last into adulthood. Alterations associated with adolescent ethanol exposure include increases in anxiety-like behavior, impulsivity, risk-taking, and ethanol intake, although the observed alterations differ as a function of exposure regimens and routes of ethanol administration. Rodent studies have also shown that adolescent ethanol exposure produces alterations in sensitivity to ethanol, with these alterations reminiscent of adolescent-typical ethanol responsiveness. The goal of this mini-review article is to summarize the current state of animal research, focusing on the long-term consequences related to adolescent ethanol exposure, with a special emphasis on the behavioral alterations and changes to ethanol sensitivity that can foster high levels of drinking in adulthood.

Reasons of drug use among adolescents: implications for clinical nursing care

Abstract This is a theoretical essay which aims to reflect on the reasons for and why adolescents use drugs and their implications for clinical nursing care. It used the referential of social phenomenology of Alfred Schutz. The main reasons identified were: to attenuate existential crisis, form social bonds and to have fun. The reasons for this are related to the characteristics of adolescence, a breakdown in social and family ties and the conditions of programmatic vulnerability. Motivations provide important information for developing person-centered, not drug-abuse-centered care strategies. Nurses’ caregiving action is based on emancipatory health education strategies grounded on the strategy of reducing harm and risks related to drug use and the possibility to help adolescents become aware of their biographical situation in a face-to-face relationship, so that they can (in knowing yourself) act to promote their health.

Is the Adolescent Brain at Greater Vulnerability to the Effects of Cannabis? A Narrative Review of the Evidence

Cannabis use during the critical neurodevelopmental period of adolescence, may lead to brain structural, functional, and histological alterations that may underpin some of the longer-term behavioral and psychological harms associated with it. The endocannabinoid system performs a key regulatory and homeostatic role, that undergoes developmental changes during adolescence making it potentially more susceptible to the effects of exposure to cannabis during adolescence. Here, we synthesize evidence from human studies of adolescent cannabis users showing alterations in cognitive performance as well as in brain structure and function with relevant preclinical evidence to summarize the current state of knowledge. We also focus on the limited evidence that speaks to the hypothesis that cannabis use during adolescence, may pose a greater risk than use during adulthood, identify gaps in current evidence and suggest directions for new research. Existing literature is consistent with the association of cannabis use during adolescence and neurological changes. Adolescence cannabis users show altered functional connectivity within known functional circuits, that may underlie inefficient recruitment of brain regions, as largely increased functional activation has been observed compared to controls. This disruption in some cases may contribute to the development of adverse mental health conditions; increasing the chances or accelerating the onset, of their development. Preclinical evidence, further supports disruption from cannabis use being specific to the developmental period. Future studies are required to better investigate adolescent cannabis use with more accuracy using better defined groups or longitudinal studies and examine the permanency of these changes following caseation of use. Furthermore, research is required to identify heritable risk factors to cannabis use. There is a need for caution when considering the therapeutic potential of cannabis for adolescence and particularly in public discourse leading to potential trivialization of possible harm from cannabis use in adolescence. Current evidence indicates that adolescence is a sensitive period during which cannabis use may result in adverse neurocognitive effects that appear to show a level of permanency into adulthood.

Nucleus accumbens connectivity at rest is associated with alcohol consumption in young male adults

Alcohol consumption during adolescence might impede normal brain development, while more excessive drinking during this period poses a risk for developing alcohol use disorder. Here it was tested whether nucleus accumbens (NAcc) resting-state functional connectivity could be associated with lifetime drinking behavior in young adults, and whether it could predict their alcohol consumption during a one-year follow-up period. The current investigation was part of the bicentric Learning and Alcohol Dependence (LeAD) population-based prospective cohort study. One hundred and eighty-four 18-year-old male social drinking volunteers without a lifetime diagnosis of psychotic, bipolar, or alcohol use disorder were recruited from the general population. Seed-based resting-state functional connectivity was calculated for the bilateral NAcc in each participant. Across the group, the association between NAcc functional connectivity and lifetime alcohol consumption was assessed (p < .05, whole-brain FWE-corrected). Individual connectivity values were then extracted from regions that demonstrated a significant association to predict drinking behavior during a one-year follow-up period (n = 143), correcting for lifetime alcohol consumption. Weaker connectivity between the left NAcc and bilateral dorsolateral prefrontal cortex, inferior frontal gyrus, left caudate nucleus, left putamen, and left insula was associated with greater lifetime alcohol consumption, as well as with greater alcohol consumption during the one-year follow-up period. Our findings underscore the relevance of fronto-striatal connectivity to the field of alcohol research. Impaired prefrontal cognitive control might mediate excessive drinking behavior and may prove a promising biomarker for risk of future alcohol (ab)use.

Differential expression of nicotine withdrawal as a function of developmental age in the rat

Cigarette smoking and resultant nicotine dependence remain major public health problems. Most smokers begin before the age of 18, yet preclinical models have insufficiently characterized the development of nicotine dependence in adolescence. To categorize the short-term effects of chronic nicotine administration throughout adolescence and adulthood, we exposed male Sprague Dawley rats to 14 days of continuously delivered nicotine (0, 1.2 or 4.8 mg/kg/d) using a subcutaneous osmotic minipump, starting between postnatal day 33 (p33) and p96. Next, to explore the effects of extended exposure to chronic nicotine, we exposed male Sprague Dawley rats to 42 days of continuous nicotine starting in adolescence (p33) or early adulthood (p68). Somatic and affective signs of precipitated withdrawal (PW) were observed after a mecamylamine (1.5 mg/kg, i.p.) challenge as compared to a saline injection. Short term nicotine exposure starting at p96, well within the adult period, elicited a significant increase in somatic PW as measured by a composite behavioral score. In contrast, adolescent exposure to nicotine elicited a unique behavioral profile, dependent on the starting age of exposure. Late adolescence exposure was characterized by scratching while adult exposure was characterized by facial tremors and yawns. Extended exposure to nicotine resulted in age specific characteristic nicotine withdrawal behaviors, including scratches, ptosis and locomotion, distinct from the short-term exposure. Thus, nicotine dependence severity, based on the expression of total somatic PW behaviors, is not observed until the adult period, and differences between adolescents and adults are observed using a more nuanced behavioral scoring approach. We conclude that age of nicotine initiation affects somatic withdrawal signs and their magnitude. These data serve as a foundation for understanding the underlying brain mechanisms of nicotine dependence and their development over adolescence and early adulthood.

Driving the Downward Spiral: Alcohol-Induced Dysregulation of Extended Amygdala Circuits and Negative Affect

Alcohol use disorder (AUD) afflicts a large number of individuals, families, and communities globally. Affective disturbances, including stress, depression, and anxiety, are highly comorbid with AUD, contributing in some cases to initial alcohol use and continued use. Negative affect has a particularly strong influence on the withdrawal/abstinence stage of addiction as individuals with AUD frequently report stressful events, depression, and anxiety as key factors for relapse. Treatment options for negative affect associated with AUD are limited and often ineffective, highlighting the pressing need for preclinical studies examining the underlying neural circuitry driving AUD-associated negative affect. The extended amygdala (EA) is a set of brain areas collectively involved in generating and regulating affect, and extensive research has defined a critical role for the EA in all facets of substance use disorder. Here, we review the expansive historical literature examining the effects of ethanol exposure on the EA, with an emphasis on the complex EA neural circuitry driving negative affect in all phases of the alcohol addiction cycle. Specifically, this review focuses on the effects of alcohol exposure on the neural circuitry in 2 key components of the EA, the central nucleus of the amygdala and the bed nucleus of the stria terminalis. Additionally, future directions are proposed to advance our understanding of the relationship between AUD-associated negative affect and neural circuitry in the EA, with the long-term goal of developing better diagnostic tools and new pharmacological targets aimed at treating negative affect in AUD. The concepts detailed here will serve as the foundation for a companion review focusing on the potential for the endogenous cannabinoid system in the EA as a novel target for treating the stress, anxiety, and negative emotional state driving AUD.

Methodological Advances in Leveraging Neuroimaging Datasets in Adolescent Substance Use Research

Purpose of Review

Recent innovations in the statistical analysis of neuroimaging data related to adolescent substance use are highlighted. Going beyond assumptions of homogeneity in small studies of regional localization, the focus is on novel approaches that integrate across regions of the brain and levels of analysis in order to detect individual differences in use along with antecedents and consequences.

Recent Findings

Three analysis approaches are considered. Multimodal approaches like the construct-network framework combine neural, behavioral (including cognitive), and self-report indicators to create comprehensive representations of risk factors for adolescent substance use. Machine learning approaches link adolescent substance use to complex patterns of brain activity detected using prediction-focused algorithms. Person-specific approaches reflect heterogeneity in functional brain connectivity associated with adolescent substance use.

Summary

When applied to specialized datasets, multimodal, machine learning, and person-specific approaches have significant potential to provide unique insights into the neural processes underlying adolescent substance use.

Experience during adolescence shapes brain development: From synapses and networks to normal and pathological behavior

Adolescence is a period of dramatic neural reorganization creating a period of vulnerability and the possibility for the development of psychopathology. The maturation of various neural circuits during adolescence depends, to a large degree, on one's experiences both physical and psychosocial. This occurs through a process of plasticity which is the structural and functional adaptation of the nervous system in response to environmental demands, physiological changes and experiences. During adolescence, this adaptation proceeds upon a backdrop of structural and functional alterations imparted by genetic and epigenetic factors and experiences both prior to birth and during the postnatal period. Plasticity entails an altering of connections between neurons through long-term potentiation (LTP) (which alters synaptic efficiency), synaptogenesis, axonal sprouting, dendritic remodeling, neurogenesis and recruitment (Skaper et al., 2017). Although most empirical evidence for plasticity derives from studies of the sensory systems, recent studies have suggested that during adolescence, social, emotional, and cognitive experiences alter the structure and function of the networks subserving these domains of behavior. Each of these neural networks exhibits heightened vulnerability to experience-dependent plasticity during the sensitive periods which occur in different circuits and different brain regions at specific periods of development. This report will summarize some examples of adaptation which occur during adolescence and some evidence that the adolescent brain responds differently to stimuli compared to adults and children. This symposium, "Experience during adolescence shapes brain development: from synapses and networks to normal and pathological behavior" occurred during the Developmental Neurotoxicology Society/Teratology Society Annual Meeting in Clearwater Florida, June 2018. The sections will describe the maturation of the brain during adolescence as studied using imaging technologies, illustrate how plasticity shapes the structure of the brain using examples of pathological conditions such as Tourette's' syndrome and attention deficit hyperactivity disorder, and a review of the key molecular systems involved in this plasticity and how some commonly abused substances alter brain development. The role of stimulants used in the treatment of attention deficit hyperactivity disorder (ADHD) in the plasticity of the reward circuit is then described. Lastly, clinical data promoting an understanding of peer-influences on risky behavior in adolescents provides evidence for the complexity of the roles that peers play in decision making, a phenomenon different from that in the adult. Imaging studies have revealed that activation of the social network by the presence of peers at times of decision making is unique in the adolescent. Since normal brain development relies on experiences which alter the functional and structural connections between cells within circuits and networks to ultimately alter behavior, readers can be made aware of the myriad of ways normal developmental processes can be hijacked. The vulnerability of developing adolescent brain places the adolescent at risk for the development of a life time of abnormal behaviors and mental disorders.

Neurobiological and Cognitive Profile of Young Binge Drinkers: a Systematic Review and Meta-Analysis

This review provides the first systematic and quantitative synthesis of the literature examining the relationship between binge drinking, cognition, brain structure and function in youth aged 10 to 24 years. PubMed, EMBASE, Medline, PsychINFO and ProQuest were searched for neuroimaging, neurophysiological, and neuropsychological studies. A total of 58 studies (21 neuroimaging, 16 neurophysiological, 21 neuropsychological) met the eligibility criteria and were included in the review. Overall, abnormal or delayed development of key frontal executive-control regions may predispose youth to binge drink. These abnormalities appear to be further exacerbated by the uptake of binge drinking, in addition to alcohol-related neural aberrations in reward-seeking and incentive salience regions, indexed by cognitive deficits and maladaptive alcohol associations. A meta-analysis of neuropsychological correlates identified that binge drinking in youth was associated with a small overall neurocognitive deficit (g = -0.26) and specific deficits in decision-making (g = -1.70), and inhibition (g = -0.39). Using the Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) Evidence Profile, the certainty in outcomes ranged from very low to low. Future prospective longitudinal studies should address concomitant factors, exposure thresholds, and age-related vulnerabilities of binge drinking, as well as the degree of recovery following discontinuation of use.

From adolescence to late aging: A comprehensive review of social behavior, alcohol, and neuroinflammation across the lifespan

The passage of time dictates the pace at which humans and other organisms age but falls short of providing a complete portrait of how environmental, lifestyle and underlying biological processes contribute to senescence. Two fundamental features of the human experience that change dramatically across the lifespan include social interactions and, for many, patterns of alcohol consumption. Rodent models show great utility for understanding complex interactions among aging, social behavior and alcohol use and abuse, yet little is known about the neural changes in late aging that contribute to the natural decline in social behavior. Here, we posit that aging-related neuroinflammation contributes to the insipid loss of social motivation across the lifespan, an effect that is exacerbated by patterns of repeated alcohol consumption observed in many individuals. We provide a comprehensive review of (i) neural substrates crucial for the expression of social behavior under non-pathological conditions; (ii) unique developmental/lifespan vulnerabilities that may contribute to the divergent effects of low-and high-dose alcohol exposure; and (iii) aging-associated changes in neuroinflammation that may sit at the intersection between social processes and alcohol exposure. In doing so, we provide an overview of correspondence between lifespan/developmental periods between common rodent models and humans, give careful consideration to model systems used to aptly probe social behavior, identify points of coherence between human and animal models, and point toward a multitude of unresolved issues that should be addressed in future studies. Together, the combination of low-dose and high-dose alcohol effects serve to disrupt the normal development and maintenance of social relationships, which are critical for both healthy aging and quality of life across the lifespan. Thus, a more complete understanding of neural systems-including neuroinflammatory processes-which contribute to alcohol-induced changes in social behavior will provide novel opportunities and targets for promoting healthy aging.

Heavy Drinking and Non-Medical Use of Prescription Drugs among University Students: A 9-Year Follow-Up

Purpose: Investigations suggest non-medical use of prescription drugs (NMUPD) is associated with heavy drinking and polydrug use among university students. Our aim is to determine the prevalence of NMUPD among university students and to analyze its association with alcohol, tobacco, and cannabis use, and to study the role of the age of drinking onset. Methods: Cohort study among university Spanish students (n = 1382). Heavy drinking (HED) and risky consumption (RC) were measured with the Alcohol Use Disorders Identification Test. Questions related to tobacco and cannabis consumption were also formulated. NMUPD refers to sedative, anxiety, or pain medication intake within the last 15 days without medical prescription. All variables were measured at 18, 20, and 27 years. Multilevel logistic regression for repeated measures was used to obtain adjusted OR (odds ratios). We analyzed the results from a gender perspective. Results: Prevalence of NMUPD were higher in students who already partook in NMUPD at the beginning of the study. NMUPD in women at 27 is 3 times higher than at 18, while in men it is twice. Among females, RC (OR = 1.43) and cannabis consumption (OR = 1.33) are risk factors for NMUPD, while later onset of alcohol use (OR = 0.66) constitutes a protective factor. No significant differences were found for males. Conclusions: NMUPD is prevalent among university students. RC and early onset of alcohol use were associated with higher prevalence of NMUPD in females. The prevalence of NMUPD increased with age in both sexes. Strategies for reducing risky drinking and delaying onset of drinking should be provided for university students. Pharmacists and parents should be alerted to the risk of NMUPD.

Cingulate glutamate levels associate with pain in chronic pancreatitis patients

Aims

Emerging evidence show that patients with chronic pancreatitis (CP) and abdominal pain have structural and functional alterations in the central nervous system. The aim was to investigate cerebral metabolic signatures in CP and the associations to various risk factors/clinical characteristics and patient outcomes.

Methods

Magnetic resonance spectroscopy was used to measure brain metabolites in the anterior cingulate cortex (ACC), insula, prefrontal cortex and the parietal region in patients with CP and healthy controls. Subgroup analyses based on disease characteristics (alcoholic etiology of CP, diabetes and opioid treatment) were performed. Finally, relations to abdominal pain symptoms and quality of life scores were explored.

Results

Thirty-one patients with CP (mean age 58.5 ± 9.2 years) and 23 healthy controls (54.6 ± 7.8 years) were included. Compared to healthy controls, patients had increased glutamate/creatine (glu/cre) levels in the ACC (1.24 ± 0.17 vs. 1.13 ± 0.21, p = .045) and reduced parietal N-acetylaspartate/creatine (NAA/cre) levels (1.44 ± 0.18 vs. 1.54 ± 0.12, p = .027). Patients with alcoholic etiology of CP had significant lower levels of parietal NAA/cre as compared to patients without alcoholic etiology and healthy controls (p < .006). Patients with a high level of ACC glu/cre reported more severe abdominal pain than their counterparts with a low level of ACC glu/cre (pain score 4.1 ± 2.7 vs.1.9 ± 2.3, p = .039).

Conclusions

Cerebral spectroscopy revealed novel and complementary information on central pain mechanisms and alcohol mediated toxic effects in patients with CP. Our data suggest that cingulate glutamate levels associate with the patients clinical pain symptoms, while parietal NAA levels more likely associate with an alcoholic etiology of CP.

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Patients with chronic pancreatitis have altered brain metabolites.

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Increased cingulate glutamate levels associate with clinical pain symptoms.

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Decreased parietal N-acetylaspartate levels likely relate to alcoholic etiology.

Alterations in White Matter Microstructure and Connectivity in Young Adults with Alcohol Use Disorder

BACKGROUND

Magnetic resonance imaging (MRI) studies have shown differences in volume and structure in the brains of individuals with alcohol use disorder (AUD). Most research has focused on neuropathological effects of alcohol that appear after years of chronic alcohol misuse. However, few studies have investigated white matter (WM) microstructure and diffusion MRI-based (DWI) connectivity during early stages of AUD. Therefore, the goal of this work was to investigate WM integrity and structural connectivity in emerging adulthood AUD subjects using both conventional DWI metrics and a novel connectomics approach.

METHODS

Twenty-two AUD and 18 controls (CON) underwent anatomic and diffusion MRI. Outcome measures were scalar diffusion metrics and structural network connectomes. Tract-Based Spatial Statistics was used to investigate group differences in diffusion measures. Structural connectomes were used as input into a community structure procedure to obtain a coclassification index matrix (an indicator of community association strength) for each subject. Differences in coclassification and structural connectivity (indexed by streamline density) were assessed via the Network Based Statistics Toolbox.

RESULTS

AUD had higher fractional anisotropy (FA) values throughout the major WM tracts, but also had lower FA values in WM tracts in the cerebellum and right insula (p_TFCE  < 0.05). Mean diffusivity was generally lower in the AUD group (p_TFCE  < 0.05). AUD had lower coclassification of nodes between ventral attention and default mode networks and higher coclassification between nodes of visual, default mode, and somatomotor networks. Additionally, AUD had higher fiber density between an adjacent pair of nodes within the default mode network.

CONCLUSIONS

Our results indicate that emerging adulthood AUD subjects may have differential patterns of FA and distinct differences in structural connectomes compared with CON. These data suggest that such alterations in microstructure and structural connectivity may uniquely characterize early stages of AUD and/or a predisposition for development of AUD.