Adolescent neurodevelopment

Potential roles for microglia in drug addiction: Adolescent neurodevelopment and beyond

Adolescence is a sensitive period for development of addiction-relevant brain circuits, and it is also when people typically start experimenting with drugs. Unfortunately, such substance use may cause lasting impacts on the brain, and might increase vulnerability to later-life addictions. Microglia are the brain's immune cells, but their roles in shaping neural connectivity and synaptic plasticity, especially in developmental sensitive periods like adolescence, may also contribute to addiction-related phenomena. Here, we overview how drugs of abuse impact microglia, and propose that they may play poorly-understood, but important roles in addiction vulnerability and progression.

Maternal nut and fish consumption during pregnancy and child risky decision-making at 11 years old

Antenatal diet may have a role in the development of impulsivity, and hence in risky decision-making. This study is assessing whether nut and fish consumption during pregnancy is associated with impulsivity and risky decision-making until pre-adolescence. This is a mother-child population-based birth cohort study, INMA (Infancia y Medio Ambiente) project (recruitment years 2004-2008). The final sample included 1386 healthy preadolescents and their mothers. The exposure variables included maternal nut and fish consumption during the first trimester of pregnancy from a validated food frequency questionnaire (FFQ). The main outcomes were impulsivity index (Attention Network Task, ANT) and the number of risky decision-making (Roulette Task). The association was estimated by multi-variable linear regression models. Children whose mothers were at the highest nut intake tertile showed less risky decision scores compared to those at the lowest tertile (β = -1.49, 95%CI = -2.85; -0.14; p-for-trend = 0.03). Fish consumption showed a positive association with ANT impulsivity index (the coefficient for second quintile compared to the lowest β = 65.73, 95%CI = 1.11; 130.35), with a p-value < 0.05 and a p-for-trend = 0.61. Although, no association was observed between fish consumption and risky decision-making outcome. Our study suggests that a higher nut intake during early pregnancy may be related with less risky decision-making in the 11-year-old children. Also, that a moderate intake of fish during early pregnancy seems to be associated with higher impulsivity in the offspring. The latter finding may be indicative of no benefits observed from seafood consumption.

Effects of adolescent morphine exposure on brain stimulation reward sensitivity and dopamine neuron excitability

Adolescent substance abuse drives lasting changes in reward processing and decision making. To determine the effects of opioid treatment and withdrawal on reward sensitivity during adolescence, we used a rate-frequency (RF) intracranial self-stimulation (ICSS) paradigm in adolescent rats. On PD28, rats were implanted with stimulating electrodes in the medial forebrain bundle at the level of the lateral hypothalamus and trained twice-daily to perform a variant RF ICSS task tailored for adolescents. Morphine (5 mg/kg) or saline (0.5 ml/kg) was injected daily prior to the AM ICSS session from PD45-51 and we continued to perform sessions through PD60 to measure withdrawal. Rats were then trained on a standard adult RF ICSS task. All animals were tested from PD90-96 while undergoing daily morphine administration (10mg/kg) and for an additional 9 days of withdrawal. In adolescent controls, reward sensitivity was stable across baseline, injection, and post-injection sessions. Adolescent morphine administration resulted in a significant increase in reward sensitivity relative to controls followed by a reduction lasting for the entire 9-day withdrawal period. Re-exposure to morphine in adulthood resulted in a greater increase in sensitivity during administration and a more profound suppression in withdrawal relative to those that had not been exposed to morphine in adolescence. In a separate group of animals, withdrawal from adolescent morphine treatment resulted in reduced electrophysiological excitability of ventral tegmental area dopamine neurons that may contribute to lasting alterations in reward sensitivity. Such alterations following adolescent morphine exposure may drive susceptibility to maladaptive behaviors in adulthood.

Triple network dynamics and future alcohol consumption in adolescents

BACKGROUND

The human brain is a highly interconnected and dynamic system. The study of neuroimaging indicators of future teen drinking has primarily focused on the activation of individual brain regions. We applied novel methodology to identify relationships between functional brain network dynamics and future drinking outcomes in non/low drinking teens.

METHODS

Resting-state functional magnetic resonance imaging (fMRI) time series from 17-year-old non-/low drinking participants (n = 295) of the National Consortium on Alcohol and NeuroDevelopment in Adolescence (NCANDA) study were used to fit a Hidden semi-Markov Model (HSMM). Regions of the default mode network (DMN), salience network (SN), and central executive network (CEN), collectively known as the Triple Network, were included in modeling. The HSMM identified each participant's most likely brain state sequence through five brain states. Poisson regression models assessed relationships between occupancy time in brain states and future drinking frequency/intensity. Sex differences were assessed with permutation testing and interaction terms in regression models.

RESULTS

No sex differences in network dynamics were observed. However, the relationship between occupancy times and future drinking frequency differed by sex for three brain states. Occupancy time in a state characterized by high activation in the DMN and SN, but low activation in the CEN, was negatively associated with future drinking in both sexes.

CONCLUSIONS

Brain network dynamics may be useful neural markers of teen drinking predisposition. Brain dynamics that make teens vulnerable or resilient to drinking may differ between sexes.

Higher alcohol use is associated with subsequent increased risk seeking toward gains: A longitudinal cohort study in young men

BACKGROUND

A higher propensity for impulsive and risky choices has often been reported in individuals with addiction, such as alcohol use disorder (AUD). Although domains of choice impulsivity, for example, temporal discounting, have been identified to predispose the development of hazardous alcohol use, research on altered decision making as a consequence of drinking is scarce. These may be particularly pronounced during periods of progressive brain development, such as young adulthood.

METHODS

This 3-year prospective study investigated the effects of alcohol use on changes in four decision-making domains in 18-year-old men (N = 130). We assessed temporal changes in discounting of delayed rewards, risk aversion for gains, risk seeking for losses, and loss aversion. By correlating three-year cumulative alcohol consumption and total binge drinking frequency with respective change scores, we aimed to explore the influences of drinking on altered development in different impulsive choice tendencies.

RESULTS

From ages 18 to 21, choice impulsivity in our moderately drinking cohort decreased significantly with respect to temporal discounting and risk aversion for gains, while risk seeking for losses and loss aversion did not change significantly. Importantly, higher cumulative alcohol intake and more binge drinking occasions over 3 years were associated with slower increases in risk aversion for gains, that is, the general trend for lower choice impulsivity was diminished. Such relationships were not found for temporal discounting, risk seeking for losses, or loss aversion.

CONCLUSIONS

Alcohol consumption in young adulthood is linked to stunted development of risk aversion for gains. Given that risk seeking for gains was previously identified as a risk factor for increasing alcohol intake, this relationship may reinforce a spiral of escalating consumption over time. The absence of similar findings in other decision-making domains suggests that drinking behavior and modifying factors interact differently across domains, rather than universally enhancing impulsive choice behavior.

Lifespan investigation of brain volumetric changes associated with substance use disorders

Substance use disorder (SUD) stands as a critical public health concern, contributing to substantial morbidity, mortality and societal costs. The effects of SUD on structural brain changes have been well documented. However, the neural mechanisms underlying SUD and the spatial-temporal volumetric changes associated with SUD remained underexplored. In this investigation, neuroimaging, behavioral and genomic data across four large population cohorts jointly covering the full lifespan were harmonized, and whole-brain volumetric trajectories between substance use disorders (SUDs) and healthy controls (HCs) were compared, revealing the potential neurobiological mechanisms and the genomic basis underlying SUD. Results highlighted three distinct life stages critical for the development of SUD: 1) adolescence to early adulthood (before 25y), where SUD is suspected to be the consequence of prefrontal-subcortical imbalance during neurodevelopment; 2) early-to-mid adulthood (25y - 45y), where SUD was strongly associated with compulsivity-related brain volumetric changes; 3) mid-to-late adulthood (after 45y), where SUD-related brain structural changes could be explained by neurotoxicity. Results were externally validated both via longitudinal analysis of these population cohorts and in independent cross-sectional samples. In summary, our study demonstrated the lifespan whole-brain volumetric changes associated with SUD, revealed potential neurobehavioral mechanisms for the development of SUD, and suggested critical time window for effective prevention and treatment of SUD.

Developing brain asymmetry shapes cognitive and psychiatric outcomes in adolescence

Cerebral asymmetry, fundamental to various cognitive functions, is often disrupted in neuropsychiatric disorders. While brain growth has been extensively studied, the maturation of brain asymmetry in children and the factors influencing it in adolescence remain poorly understood. We analyze longitudinal data from 11,270 children aged 10-14 years in the Adolescent Brain Cognitive Development (ABCD) study. Our analysis maps the developmental trajectory of structural brain asymmetry. We identify significant age-related, modality-specific development patterns. These patterns link to crystallized intelligence and mental health problems, but with weak correlations. Genetically, structural asymmetry relates to synaptic processes and neuron projections, likely through asymmetric synaptic pruning. At the microstructural level, corpus callosum integrity emerged as a key factor modulating the developing asymmetry. Environmentally, favorable perinatal conditions were associated with prolonged corpus callosum development, which affected future asymmetry patterns and cognitive outcomes. These findings underscore the dynamic yet predictable interactions between brain asymmetry, its structural determinants, and cognitive and psychiatric outcomes during a pivotal developmental stage. Our results provide empirical support for the adaptive plasticity theory in cerebral asymmetry and offer insights into both cognitive maturation and potential risk for early-onset mental health problems.

Post-intervention neuroimaging effects of psychosocial interventions aimed at promoting resilience in children and adolescents under psychological stress: A systematic review

Childhood and adolescence are neurodevelopmentally critical periods, during which psychological adversity can increase the risk of subsequent mental health difficulties. However, the increased neuroplasticity during this window also confers potential for developing resilience, which is now seen as a dynamic process of adapting to adversity. This pre-registered systematic review (PROSPERO-CRD42024537715) summarises the post-intervention neuroimaging outcomes of non-invasive, non-pharmacological interventions aimed at promoting resilience in samples with a mean age of < 25 years exposed to any explicit psychological stress. Studies involving traumatic or focal brain lesions were excluded. MEDLINE, PsycINFO and CENTRAL databases were searched from inception to 14/7/2024. Magnetic Resonance Imaging (MRI) outcomes were the primary focus. Risk of bias was assessed against adapted Joanna Briggs Institute checklist items. A narrative synthesis was conducted due to study heterogeneity. We identified 13 eligible studies: 1 reporting structural and diffusion-weighted MRI (performed after 2 years of intervention), 1 resting-state fMRI (14 years after end of intervention) and 11 task-based fMRI metrics (ranging from immediately post-intervention to 8 years after end of intervention). Resilience interventions reduce limbic activity (thalamus, amygdala and right anterior insula) in task-based fMRI. In older adolescents, social, mindfulness, and exercise interventions strengthen Prefrontal Cortex(PFC)-limbic connectivity, decreasing limbic activity. Evidence in younger adolescents is sparse, showing mixed effects on PFC-limbic connectivity. Five studies were at high risk of bias; the most common limitation was no pre-intervention MRI scans. Overall, this study summarises promising mechanisms, as demonstrated on neuroimaging, through which resilience can be enhanced in stressed youth through psychosocial interventions.

Direct and indirect pathways linking gentrification to adolescent reading and math achievement via educational aspirations and psychological distress

This study examined how living in a gentrifying neighborhood may impact adolescents' reading and math achievement via educational aspirations and psychological distress and asked whether these pathways differ according to socioeconomic status and race. A framework combining theories of adolescent development and neighborhood effects was empirically tested using a racially diverse sample of adolescents living in urban neighborhoods in North Carolina matched to administrative school records and census data (N = 1,045, Mage = 12, 8% American Indian, 4% Asian, 32% Black, 62% White, 15% multiracial, 16% Latinx, categories not mutually exclusive). At the population level, structural equation models found no relation between the extent of gentrification occurring in youths' neighborhood of residence and reading and math achievement, educational aspirations, or psychological distress. However, moderated mediation models revealed a positive association between gentrification and psychological distress among youth with low (but not high) subjective family economic status, leading to a small negative indirect effect of gentrification on math achievement. The link between gentrification and increased psychological distress was largest among Black youth with low subjective family economic status, who may face both heightened racism and classism-related social stressors as their neighborhood gentrifies. Findings have theoretical and policy implications, as they challenge the assumption that living in proximity to higher income, higher educated peers will benefit youth from disadvantaged neighborhoods. (PsycInfo Database Record (c) 2025 APA, all rights reserved).

Disruptions in Reward-Guided Decision-Making Functions Are Predictive of Greater Oral Oxycodone Self-Administration in Male and Female Rats

Background

Problematic opioid use that emerges in a subset of individuals may be due to preexisting disruptions in the biobehavioral mechanisms that regulate drug use. The identity of these mechanisms is not known, but emerging evidence suggests that suboptimal decision making that is observable prior to drug use may contribute to the pathology of addiction.

Methods

The current study investigated the relationship between decision-making phenotypes and opioid-taking behaviors in male and female Long Evans rats. Adaptive decision-making processes were assessed using a probabilistic reversal learning task and oxycodone- (or vehicle, as a control) taking behaviors assessed daily in 32 sessions using a saccharin fading procedure that promoted dynamic intake of oxycodone. Tests of motivation, extinction, and reinstatement were also performed.

Results

Computational analyses of decision-making data identified data-driven metrics that predicted self-administration of oxycodone and addiction-relevant behaviors. Moreover, preexisting impairments in reward-guided decision making observed in female rats were associated with greater addiction-relevant behaviors when compared with males.

Conclusions

These results provide new insights into the biobehavioral mechanisms that regulate opiate-taking behaviors and offer a novel phenotypic approach for interrogating sex differences in addiction susceptibility and opioid use disorders.

The impact of maternal premating stress on the postnatal outcomes of offspring in rodent studies: A systematic review

Maternal premating stress (mPMS) has been linked to adverse outcomes in the next generation. In this systematic review, we examined the impact of mPMS on offspring's neurodevelopmental milestones, behavioral outcomes, and physiological alterations before and after adulthood in rodent studies. We conducted a systematic literature review using PubMed, Scopus, ProQuest, and APA PsycNet, using the terms "premating stress", "pregestational stress", "prepregnancy stress, and "preconception stress". Thirty studies that met exclusion and inclusion criteria and contained relevant data were included. The reviewed literature suggests that mPMS can delay progeny's neurobehavioral development during the first week of life and increase their stress\anxiety- and depression-like behaviors, especially before postnatal day 60. Furthermore, male offspring's memory abilities may be impaired, although learning ability remained intact in both sexes. Finally, mPMS appear to have a negative impact mainly on male offsprings' social behaviors. Some physiological alterations are discussed in relation to these behavioral outcomes, but cautiously, as studies' foci were highly diverse and prevented identifying consistent patterns of results. We also note that dams' recovery period, stress intensity and severity, type, duration, and offspring's weaning age should be considered in future studies.

Perturbations of CB1 receptor signalling during adolescence impair cortical myelination in female rats

The constant increase in cannabis use among adolescents raises concerns about its potential neurobehavioral effects. Adolescence is a critical period for brain development, involving significant changes in grey and white matter. Grey matter decreases as the brain undergoes synaptic pruning, while white matter increases due to myelination. Cannabis use during this developmental window, particularly its active ingredient delta-9-tetrahydrocannabinol (THC), may disrupt these processes, increasing the risk of developing psychiatric disorders later in life. While the impact of THC on grey matter has been explored, the specific role of CB1 receptors as well as the effect of THC exposure in adolescent myelination remain unclear. This study investigates how CB1 receptor blockade and THC exposure during adolescence affect myelination in the prefrontal cortex of female rats. Blocking CB1 receptors during adolescence hindered myelination in the prefrontal cortex. Behaviourally, this disruption in myelin formation was associated with increased risk-taking behaviour. Notably, our data suggest that alterations in the AKT/Hippo/YAP signalling pathway may play a crucial role in mediating these effects. Supporting the involvement of the endocannabinoid system in cortical myelination during adolescence, we found that administering exogenous THC impaired myelin formation only when given during early to mid-adolescence. Moreover, when a more intensive THC exposure protocol was applied during this developmental period, the effects on myelination were long-lasting and persisted into adulthood. Overall, these data support a role for CB1 receptors in shaping cortical myelination in adolescent female rats and show that adolescent exposure to THC might adversely impact this developmental process.

The shifting landscape of the preterm brain

Preterm birth remains a significant global health concern despite advancements in neonatal care. While survival rates have increased, the long-term neurodevelopmental consequences of preterm birth persist. Notably, the profile of the preterm infant has shifted, with infants at earlier gestational ages surviving and decreased rates of gross structural injury secondary to intracranial hemorrhage. However, these infants are still vulnerable to insults, including hypoxia-ischemia, inflammation, and disrupted in utero development, impinging on critical developmental processes, which can lead to neuronal and oligodendrocyte injury and impaired brain function. Consequently, preterm infants often experience a range of neurodevelopmental disorders, such as cognitive impairment and behavioral problems. Here, we address mechanisms underlying preterm brain injury and explore existing and new investigational therapeutic strategies. We discuss how gestational age influences brain development and how interventions, including pharmacological and non-pharmacological approaches, mitigate the effects of preterm birth complications and improve the long-term outcomes of preterm infants.

Single-Nucleus Transcriptomics Identifies Neuroblast Migration Programs Sensitive to Reelin and Cannabis in the Adolescent Nucleus Accumbens

The interplay between cannabis exposure during adolescence and genetic predisposition has been linked to increased vulnerability to psychiatric disorders. To investigate the molecular underpinnings of this interaction, we performed single-nucleus RNA sequencing of the nucleus accumbens (NAc) in a mouse model of Reln haploinsufficiency, a genetic risk factor for psychiatric disorders, following adolescent exposure to tetrahydrocannabinol (THC), the primary psychoactive component of cannabis. We identified a gene co-expression network influenced by both Reln genotype and THC, enriched in genes associated with human psychiatric disorders and predominantly expressed in a GABAergic neuroblast subpopulation. We showed that neuroblasts actively migrated in the adolescent NAc, but declined with age. Cell-to-cell communication analysis further revealed that these neuroblasts receive migratory cues from cholecystokinin interneurons, which express high levels of cannabinoid receptors. Together, these findings provide mechanistic insights into how adolescent THC exposure and genetic risk factors may impair GABAergic circuit maturation.

Purdue manual dexterity testing: Normative data from young people from Turkey

BACKGROUND

The Purdue Pegboard Test (PPT) is a widely used tool to measure manual dexterity. Since manual dexterity is highly important for participation in education and the workforce, determining its normative values within specific age categories and cultural contexts is of critical importance.

PURPOSE

The aim of the study was to determine normative values for manual dexterity in young people and to investigate the relationship between these values and certain determinants.

STUDY DESIGN

A cross-sectional study.

METHODS

A total of 774 young participants attending selected schools participated in the study using a convenience sampling method. The participants' manual dexterity was assessed using the PPT, including tasks for the right-left hand, both hands, and assembly tasks. Mean scores were analyzed using an independent-sample t-test and one-way Anova test of variance.

RESULTS

It was found that participants performed better in manual dexterity when using their dominant hands, female gender, and increasing age. There was no significant difference in PPT test scores based on the number of siblings or the presence of chronic illness (p > 0.05). Regarding regular sports participation, there was a significant difference in mean scores for PPT right and left hand tasks in favor of those who engage in regular sports (p < 0.05), while there was a significantly greater difference between both hands and assembly tasks (p < 0.01). There was a significant difference in mean scores for PPT right hand tasks in favor of those who regularly play musical instruments (p < 0.05).

CONCLUSIONS

The results provide normative data that can be used to assess the manual dexterity of young people. It is believed that systematically examining the manual dexterity of young individuals and evaluating it in the context of the presented normative values will contribute to the early detection of deficiencies and impairments that may negatively affect productivity and the acquisition of vocational skills.

Age- and sex-dependent participation of the endocannabinoid system in locomotion and risk assessment of an ADHD rat model

Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder affecting individuals across age groups. Impairments in executive function characterize ADHD and are often associated with elevated levels of risk-taking behaviors. The endocannabinoid system plays a crucial role in modulating prefrontal cortex circuits. Here, we assessed the effects of acute pharmacological manipulation of cannabinoid CB1 and CB2 receptors on locomotion and risk assessment/anxiety-like behaviors in an ADHD animal model during adolescence and adulthood. Further, we investigated the protein levels and gene expression of endocannabinoid system components (CB1, CB2, FAAH, MAGL) in the prefrontal cortex at both ages. During adolescence, activation of cannabinoid receptors aggravated the hyperactivity and risky behaviors of the ADHD model. These behavioral traits were more evident in female rats. In adulthood, manipulation of cannabinoid receptors did not alter hyperactivity but worsened risk assessment. Overall, gene expression levels of receptors and enzymes of the endocannabinoid system were increased in the ADHD model. Our findings suggest that the endocannabinoid system may operate differently in ADHD, and manipulating this system, especially in adolescents, could exacerbate deficits in inhibitory control.

It's not what you say it's what you do: School diversity ideologies and adolescent mental health and academic engagement

This study examined the relation between schools' color-evasive versus multicultural diversity ideologies, school characteristics, and adolescent development. Across two datasets linking individual-level survey data (N = 1692) and administrative records (N = 300,063; Mage = 12.4, 52% female, 48% male), schools' stated support for diversity (via a pro-diversity mission statement) was related to adolescent mental health and academic achievement, but in nuanced ways depending on individual racial/ethnic backgrounds, the racial/ethnic diversity of the student body and teachers, and the extent of racial disparities in discipline and gifted education. Findings suggest that communicating support for diversity without redressing systemic inequities in school discipline and academic tracking will not reduce racism-related achievement gaps and may instead exacerbate mental health disparities.

Long-term effects of adolescent versus adult nicotine self-administration on cholinergic modulation of dopamine in the nucleus accumbens core

Adolescence is a developmental period marked by significant alterations to brain neurobiology and behavior. Adolescent nicotine use disrupts developmental trajectories and increases vulnerability to maladaptive drug-taking in adulthood. The mesolimbic dopamine (DA) system, including the nucleus accumbens core (NAc), mediates the reinforcing effects of nicotine. While dopaminergic reorganization is necessary for the transition into adulthood, how adolescent nicotine exposure affects cholinergic modulation of adult NAc DA dynamics is less understood. Here, we use 12 days of intravenous self-administration (SA) and ex vivo fast-scan cyclic voltammetry (FSCV) to explore the effects of adolescent (P31-42) versus adult (P63-75) nicotine (0.03mg/kg/infusion) intake on DA dynamics following three weeks of forced abstinence in adult male rats. This three-week abstinence period ensured that all neurochemical measurements were performed in adulthood. Consistent with the literature, we show that adolescent and adult male rats self-administer similar amounts of nicotine. While adult nicotine exposure + forced abstinence decreased NAc DA release relative to adult saline exposure, we found no difference in adult NAc DA release after adolescent nicotine or saline exposure. Investigating α6-versus non-α6-containing nicotinic acetylcholine receptors (nAChRs) revealed differential modulatory effects in adults and adolescents self-administering nicotine relative to respective saline controls. Both α6- and non-α6β2-containing nAChRs facilitation of NAc DA release was increased across frequencies only after adolescent nicotine versus saline SA. These data provide a foundation for understanding the long-term effects of nicotine in adolescence on cholinergic modulation of NAc DA dynamics in adulthood.

Decoding Brain Development and Aging: Pioneering Insights From MRI Techniques

ABSTRACT

The aging process induces a variety of changes in the brain detectable by magnetic resonance imaging (MRI). These changes include alterations in brain volume, fluid-attenuated inversion recovery (FLAIR) white matter hyperintense lesions, and variations in tissue properties such as relaxivity, myelin, iron content, neurite density, and other microstructures. Each MRI technique offers unique insights into the structural and compositional changes occurring in the brain due to normal aging or neurodegenerative diseases. Age-related brain volume changes encompass a decrease in gray matter and an increase in ventricular volume, associated with cognitive decline. White matter hyperintensities, detected by FLAIR, are common and linked to cognitive impairments and increased risk of stroke and dementia. Tissue relaxometry reveals age-related changes in relaxivity, aiding the distinction between normal aging and pathological conditions. Myelin content, measurable by MRI, changes with age and is associated with cognitive and motor function alterations. Iron accumulation, detected by susceptibility-sensitive MRI, increases in certain brain regions with age, potentially contributing to neurodegenerative processes. Diffusion MRI provides detailed insights into microstructural changes such as neurite density and orientation. Neurofluid imaging, using techniques like gadolinium-based contrast agents and diffusion MRI, reveals age-related changes in cerebrospinal and interstitial fluid dynamics, crucial for brain health and waste clearance. This review offers a comprehensive overview of age-related brain changes revealed by various MRI techniques. Understanding these changes helps differentiate between normal aging and pathological conditions, aiding the development of interventions to mitigate age-related cognitive decline and other symptoms. Recent advances in machine learning and artificial intelligence have enabled novel methods for estimating brain age, offering also potential biomarkers for neurological and psychiatric disorders.

Task-Rest Reconfiguration Efficiency of the Reward Network Across Adolescence and Its Association With Early Life Stress and Depressive Symptoms

OBJECTIVE

Adolescents face significant changes in many domains of their daily lives that require them to flexibly adapt to changing environmental demands. To shift efficiently among various goals, adolescents must reconfigure their brains, disengaging from previous tasks and engaging in new activities.

METHOD

To examine this reconfiguration, we obtained resting-state and task-based functional magnetic resonance imaging (fMRI) scans in a community sample of 164 youths. We assessed the similarity of functional connectivity (FC) of the reward network between resting state and a reward-processing state, indexing the degree of reward network reconfiguration required to meet task demands. Given research documenting relations among reward network function, early life stress (ELS), and adolescent depression, we examined the association of reconfiguration efficiency with age across adolescence, the moderating effect of ELS on this association, and the relation between reconfiguration efficiency and depressive symptoms.

RESULTS

We found that older adolescents showed greater reconfiguration efficiency than younger adolescents and, furthermore, that this age-related association was moderated by the experience of ELS.

CONCLUSION

These findings suggest that reconfiguration efficiency of the reward network increases over adolescence, a developmental pattern that is attenuated in adolescents exposed to severe ELS. In addition, even after controlling for the effects of age and exposure to ELS, adolescents with higher levels of depressive symptoms exhibited greater reconfiguration efficiency, suggesting that they have brain states at rest that are more strongly optimized for reward processing than do asymptomatic youth.

PLAIN LANGUAGE SUMMARY

Adolescents face significant changes in many domains of their lives which requires them to flexibly adapt and reconfigure their brains to disengage from previous tasks and engage in new activities. In this study of a sample of 164 youth aged 9 to 20, the authors found an age-related increase in the reconfiguration efficiency of the reward network, which was pronounced in older adolescents exposed to severe early life stress. In addition, the study findings indicate that adolescents with higher levels of depressive symptoms showed greater reconfiguration efficiency, suggesting that their brains may be more optimized for processing rewards even at rest compared to their peers without any symptoms.

DIVERSITY & INCLUSION STATEMENT

We worked to ensure race, ethnic, and/or other types of diversity in the recruitment of human participants. We worked to ensure sex and gender balance in the recruitment of human participants. We worked to ensure that the study questionnaires were prepared in an inclusive way. One or more of the authors of this paper self-identifies as a member of one or more historically underrepresented racial and/or ethnic groups in science.

Temporal dynamics of negative emotion regulation: Insights from facial electromyography

Emotion regulation (ER) is a multifaceted process that unfolds over time. This study investigated the temporal dynamics of ER on negative affect (NA) and positive affect (PA). We examined whether NA and PA changes occur sequentially or concurrently. After participants had been exposed to unpleasant pictures for 8000 ms, they received instructions to either continue viewing the picture (no regulation) or reappraise it with a neutral meaning (neutralize goal) or positive meaning (transform goal) for another 8000 ms. We obtained corrugator supercilii and zygomaticus major electromyography (EMG) as objective measures of NA and PA. For the no-regulation condition, upon instruction onset, we observed maintained high corrugator and low zygomaticus EMG reactivity, indicating sustained NA activation. Compared to no-regulation, for the neutralize goal, we observed corrugator reduction starting at 1500 ms after instruction onset and no change in zygomaticus, indicating decreased NA and generation of neutral emotion. For the transform goal, we observed corrugator reduction starting at 1000 ms and zygomaticus increase at 3500 ms after instruction onset, indicating decreased NA and increased PA and generation of positive emotion. Model-fitting analyses showed that the best-fitting trajectory for the transform goal's pattern of change was initial NA reduction that turns into PA increase at 2000 ms. These distinct temporal patterns highlight the possibility of effecting one-dimensional NA change with the neutralize goal and sequential two-dimensional change (first decreasing NA, then increasing PA) with the transform goal. This research sheds light on the time course of emotional change generated by different emotion goals.

Co-methylation networks associated with cognition and structural brain development during adolescence

Introduction

Typical adolescent neurodevelopment is marked by decreases in grey matter (GM) volume, increases in myelination, measured by fractional anisotropy (FA), and improvement in cognitive performance.

Methods

To understand how epigenetic changes, methylation (DNAm) in particular, may be involved during this phase of development, we studied cognitive assessments, DNAm from saliva, and neuroimaging data from a longitudinal cohort of normally developing adolescents, aged nine to fourteen. We extracted networks of methylation with patterns of correlated change using a weighted gene correlation network analysis (WCGNA). Modules from these analyses, consisting of co-methylation networks, were then used in multivariate analyses with GM, FA, and cognitive measures to assess the nature of their relationships with cognitive improvement and brain development in adolescence.

Results

This longitudinal exploration of co-methylated networks revealed an increase in correlated epigenetic changes as subjects progressed into adolescence. Co-methylation networks enriched for pathways involved in neuronal systems, potassium channels, neurexins and neuroligins were both conserved across time as well as associated with maturation patterns in GM, FA, and cognition.

Discussion

Our research shows that correlated changes in the DNAm of genes in neuronal processes involved in adolescent brain development that were both conserved across time and related to typical cognitive and brain maturation, revealing possible epigenetic mechanisms driving this stage of development.

Depression in adolescence and young adulthood: the difficulty to integrate motivational/emotional systems

Depression is presented as a multi-factorial bio-psycho-social expression that has evolved primarily as an effect of stressors related to the motivational/emotional systems that regulate the BrainMind in our relationship with conspecifics. These stressors may be caused by two sources of threat, firstly, the loss of bonding with the caregiver and later with a partner and/or group which relates to the SEPARATION (PANIC/GRIEF) system, secondly, social defeat as an expression of the social competition and social dominance. The sexual maturity drives the individual to social competition and social dominance, even if the latter often occurs before sexual maturity, e.g., chickens, dogs, non-human primates, and humans. Depression is an evolutionarily conserved mechanism in mammals to terminate both separation anxiety, so as to protect the vulnerable social brain from the consequences of prolonged separation anxiety, and the stress of social competition when social defeat is predictable. Adolescence and Young adulthood are particularly susceptible to these two types of threat because of human developmental characteristics that are summarized by the term neoteny. This refers to the slowing down of growth and development, resulting in both a prolonged period of dependence on a caring/protective adult and the persistence of juvenile characteristics throughout life. Therefore, neoteny makes the transition from childhood to sexual maturity more dramatic, making the integration of the SEPARATION (PANIC/GRIEF) system with the dynamics of social competition and dominance more stressful and a source of depression. Stress is an expression of the HPA-Hypothalamic-Pituitary-Adrenal axis that articulates with other systems, mainly the autonomic nervous system and the immune-inflammatory system. The latter is believed to be one of the most significant components in the dynamics of depressive processes, connected to the prodromes of its activation in childhood, under the pressure of environmental and relational stressors which can lead to learned helplessness. The recurrence of stressors makes it easier for the immune-inflammatory system to be activated in later life, which could make a significant contribution to the establishment of a depressive disease. The possible contribution of children's identification processes with their parents' depressive personalities through observational learning is considered.

Exploring the Relationship of Dietary Intake With Inattention, Hyperactivity, and Impulsivity, Beyond ADHD

OBJECTIVES

This study investigates the association between dietary intake and ADHD diagnosis and its dimensions in adolescents.

METHODS

In the KOALA Birth Cohort Study, 810 adolescents aged 16 to 20 years provided information on ADHD diagnosis and completed a food frequency questionnaire. Dietary patterns were extracted using Principal Component Analysis. Parents reported on ADHD symptoms using the Conners' Parent Rating Scale-Revised Short form, and the Impulsivity subscale from the Temperament in Middle Childhood Questionnaire.

RESULTS

The 80 adolescents with ADHD scored higher on the Snacking dietary pattern compared to those without ADHD, while they did not differ on Healthy, Animal-based, Sweet, or Beverage dietary patterns. All ADHD symptom scores (Hyperactivity, Inattention and Impulsivity, and ADHD-index) correlated with increased Snacking. Impulsivity was inversely related to Sweet dietary patterns and positively to Beverage dietary patterns.

CONCLUSION

The results highlight the importance of considering ADHD dimensions beyond diagnosis in understanding adolescents' dietary intake.

Prelimbic cortex perineuronal net expression and social behavior: Impact of adolescent intermittent ethanol exposure

Adolescent intermittent ethanol (AIE) exposure in rats leads to social deficits. Parvalbumin (PV) expressing fast-spiking interneurons in the prelimbic cortex (PrL) contribute to social behavior, and perineuronal nets (PNNs) within the PrL preferentially encompass and regulate PV interneurons. AIE exposure increases PNNs, but it is unknown if this upregulation contributes to AIE-induced social impairments. The current study was designed to determine the effect of AIE exposure on PNN expression in the PrL and to assess whether PNN dysregulation contributes to social deficits elicited by AIE. cFos-LacZ male and female rats were exposed every other day to tap water or ethanol (4 g/kg, 25% w/v) via intragastric gavage between postnatal day (P) 25-45. We evaluated neuronal activation by β-galactosidase expression and PNN levels either at the end of the exposure regimen on P45 and/or in adulthood on P70. In addition, we used Chondroitinase ABC (ChABC) to deplete PNNs following adolescent exposure (P48) and allowed for PNN restoration before social testing in adulthhod. AIE exposure increased PNN expression in the PrL of adult males, but decreased PNNs immediately following AIE. Vesicular glutamate transporter 2 (vGlut2) and vesicular GABA transporter (vGat) near PNNs were downregulated only in AIE-exposed females. Gene expression of PNN components was largely unaffected by AIE exposure. Removal and reestablishment of PrL PNNs by ChABC led to upregulation of PNNs and social impairments in males, regardless of adolescent exposure. These data suggest that AIE exposure in males upregulates PrL PNNs that likely contribute to social impairments induced by AIE.

Development of Comorbid Alcohol Use and Depressive Symptoms During Late Adolescence: Examining the Roles of Emotion Regulation and Gender Differences

Depression and alcohol use are highly comorbid, and often emerge during adolescence. Depressive symptoms may precede alcohol use, via the self-medication pathway, or alcohol use may precede depressive symptoms, via the alcohol induced disruption pathway. Yet little is known about other risks for developing comorbidity via either path. The present study hypothesized that poor cognitive and physiological emotion regulation (ER) are risk factors implicated in the development of comorbid depression and alcohol use during late adolescence. Participants were 229 (113 girls) Mexican-origin youth who reported on depressive symptoms and alcohol use at ages 17 (Time 1) and 19 years (Time 2). At age 17, cognitive reappraisal (CR), an adaptive ER strategy, and baseline respiratory sinus arrhythmia (RSA), a physiological index of ER capacity, were assessed. CR, RSA and gender were examined as predictors and moderators of the developing comorbidity of alcohol use and depression in cross-lagged panel models. Lower use of CR was concurrently associated with more depressive symptoms at age 17 and predicted greater depression at age 19. Age 17 alcohol use predicted age 19 depressive symptoms for boys. Lower RSA at age 17 also predicted more depressive symptoms at age 19 for boys. Neither CR nor RSA moderated the predicted relations between depression and alcohol use. Findings supported the alcohol induced disruption model of comorbidity for boys, and showed that poor cognitive and physiological ER increased risk for exacerbating depressive symptoms in late adolescence.

Longitudinal Associations Among Socioeconomic Status, Delay Discounting, and Substance Use in Adolescence

It is unclear how delay discounting and substance use develop across adolescence and whether contextual factors alter their trajectories. The present study used a longitudinal design to examine whether socioeconomic status is related to developmental trajectories of delay discounting and substance use across adolescence. The sample included 167 adolescents (Mage = 14 at Time 1; 53% male) and their parents who participated annually across four years. Parents reported SES at Time 1 and adolescents completed delay discounting behavioral assessments and substance use questionnaires at Times 1 to 4. Bivariate latent growth curve modeling revealed that low SES was related to steeper increases in substance use from age 14 through 17, mediated through elevated delay discounting at age 14. The findings clarify the mediating role of delay discounting in linking family economic environment to the progression of substance use.

Physical activity promotes the development of cognitive ability in adolescents: the chain mediating role based on self-education expectations and learning behaviors

Cognitive ability plays a crucial role in adolescents' academic performance and subsequent career development. Although previous studies have demonstrated that physical activity, self-education expectations, and learning behaviors positively affect the cognitive development of adolescents, the extent of their influence and their mediating roles require further elucidation. This study is based on tracking survey data from 2,688 adolescents in Chinese households collected in 2018. Multiple linear regression, Propensity Score Matching, and Quantile regression were employed to analyze the impact and heterogeneity of physical activity on adolescents' cognitive ability. Furthermore, the Bootstrap mediation test was used to explore the mediating roles of self-education expectations and learning behaviors in this process. The results indicate the following: Physical activity significantly promotes adolescents' cognitive ability; for those with poorer cognitive ability, it exerts a greater impact. Moreover, in addition to its direct effects, physical activity indirectly enhances adolescents' cognitive ability through the mediation of three factors (self-education expectations, learning behaviors, self-education expectations and learning behaviors). These discoveries offer significant insights into diverse strategies for developing cognitive ability in adolescents, contributing to both theoretical research and practical interventions.

Ventral striatal-cingulate resting-state functional connectivity in healthy adolescents relates to later depression symptoms in adulthood

BACKGROUND

Depression is a significant public health concern. Identifying biopsychosocial risk factors for depression is important for developing targeted prevention. Studies have demonstrated that blunted striatal activation during reward processing is a risk factor for depression; however, few have prospectively examined whether adolescent reward-related resting-state functional connectivity (rsFC) predicts depression symptoms in adulthood and how this relates to known risk factors (e.g., childhood trauma).

METHODS

At baseline, 66 adolescents (mean age = 14.7, SD = 1.4, 68 % female) underwent rsFC magnetic resonance imaging and completed the Children's Depression Inventory (CDI). At follow-up (mean time between adolescent scan and adult follow-up = 10.1 years, SD = 1.6, mean adult age = 24.8 years, SD = 1.7), participants completed the Childhood Trauma Questionnaire (CTQ) and Beck Depression Inventory- Second Edition (BDI-2). Average rsFC was calculated between nodes in mesocorticolimbic reward circuitry: ventral striatum (VS), rostral anterior cingulate cortex (rACC), medial orbitofrontal cortex, and ventral tegmental area. Linear regressions assessed associations between rsFC, BDI-2, and CTQ, controlling for adolescent CDI, sex assigned at birth, and scan age (Bonferroni corrected).

RESULTS

Greater childhood trauma was associated with higher adulthood depression symptoms. Stronger VS-rACC rsFC during adolescence was associated with greater depression symptoms in adulthood and greater childhood trauma.

LIMITATIONS

The small sample size, limited depression severity, and seed-based approach are limitations.

CONCLUSIONS

The associations between adolescent striatal-cingulate rsFC and childhood trauma and adult depression symptoms suggest this connectivity may be an early neurobiological risk factor for depression and that early life experience plays an important role. Increased VS-rACC connectivity may represent an over-regulatory response on the striatum, commonly reported in depression, and warrants further investigation.

The Role of Oxytocin and Vasopressin in People with Borderline Personality Disorder: A Closer Look at Adolescents

Borderline personality disorder constitutes a significant medical challenge. Despite the fact that its occurrence among adolescents is currently attracting increasing interest from both clinicians and researchers, there is still insufficient data on this phenomenon. The etiology and maintenance of borderline personality disorder are not yet fully comprehended. Neuropeptides, including oxytocin and vasopressin, are considered to be involved in the development of this condition. The mechanism behind the actions of these neurohormones requires further investigation. Our work aims to collect and analyze the available research and existing hypotheses on the role of oxytocin and vasopressin in people with borderline personality disorder, with special attention drawn to adolescents suffering from this condition.

Cognitive and Behavioral Outcomes of Snoring Among Adolescents

Importance

Snoring is central to sleep-disordered breathing (SDB), which arises from nocturnal upper airway resistance. Habitual snoring is associated with cognitive and behavioral problems in young children, but less is known about these associations in adolescents.

Objective

To assess the longitudinal associations of snoring with cognition and problem behaviors among adolescents.

Design, Setting, and Participants

This cohort study was a secondary analysis of the Adolescent Brain Cognitive Development (ABCD) Study dataset (release 5.0), which enrolled 11 875 children and a parent or caregiver from June 1, 2016, to October 15, 2018, at 21 participating US research institutions and followed-up for 5 years. The analysis was performed between December 2023 and April 2024.

Exposures

Parent-reported snoring categorized as none, nonhabitual (<3 nights/week), and habitual (≥3 times/week).

Main Outcomes and Measures

Cognition was assessed using 5 measures from the National Institutes of Health Toolbox (NIH-TB), and caregiver-reported problem behaviors were assessed using the Child Behavior Checklist (CBCL), including Total Problems, Internalizing Problems, and Externalizing Problems. Longitudinal associations of snoring with these assessment measures were analyzed using linear mixed-effects models stratified by obesity. Model fits were assessed after including the fixed-effects of age, sex at birth, race, family income, follow-up time, visit type, and the random-effects of site and identification number.

Results

The study included data from 11 862 children at year 1 (mean age, 119.0 months [95% CI, 118.8 to 119.1 months]; 6164 male [52.2%]) and 11 198, 10 870, 10 064, and 4668 children at years 2 to 5, respectively. The proportion of habitual snorers decreased from 811 participants (6.8%) in year 1 to 150 participants (3.2%) in year 5. Snoring was not associated with any of the NIH-TB scores. A statistically significant association of snoring was identified with all CBCL scales. The largest-magnitude association was of snoring with the CBCL Total Problems scale among adolescents with obesity (β = 3.18; 95% CI, 2.59-3.77).

Conclusions and Relevance

In this cohort study analyzing associations of snoring with cognitive test scores and problem behaviors based on the ABCD dataset, the prevalence of snoring declined over time; snoring in adolescents was associated with problem behaviors but not cognitive deficits. These findings may aid shared decision-making regarding treatment options such as adenotonsillectomy for adolescents with SDB.

Reduced Cortical Excitability is Associated with Cognitive Symptoms in Concussed Adolescent Football Players

Background

American tackle football is associated with high rates of concussion, leading to neurophysiological disturbances and debilitating clinical symptoms. Previous investigations of the neurophysiological effects of concussion have largely ignored aperiodic neurophysiological activity, which is a marker of cortical excitability.

Purpose

We examined whether concussion during a season of high school football is related to changes in aperiodic and periodic neurophysiological activity and whether any such changes are associated with clinical outcomes.

Materials and Methods

Pre- and post-season resting-state magnetoencephalography (MEG) data were collected from 91 high school football players over as many as four seasons of play, for a total of 278 data collections. During these seasons of football play, a cohort of 10 individuals were diagnosed with concussion. MEG data were source-imaged, frequency-transformed and parameterized, and linear mixed models were used to examine effects of concussion on pre-to-post-season changes in neurophysiological activity. Scores on the Post-Concussive Symptom Inventory were correlated with pre-to-post-season neurophysiological changes to determine their clinical relevance.

Results

Concussion was associated with increased aperiodic exponents in superior frontal cortices, indicating a relative reduction in cortical excitability. This slowing of aperiodic neurophysiology mediated concussion effects on raw delta and gamma power and was associated with worse cognitive concerns across participants. Pre-to-post-season changes in aperiodic-corrected alpha and theta rhythmic activity were also decreased in posterior cortices in concussed players.

Conclusion

These findings indicate that concussion alters both the excitability and rhythmic signaling of the cortex, with differing spatial topographies and implications for clinical symptoms.

Sex-Specific Impacts of Early Life Sleep Disruption: Ethanol Seeking, Social Interaction, and Anxiety Are Differentially Altered in Adolescent Prairie Voles

Early life sleep is important for neuronal development. Using the highly social prairie vole rodent model, we have previously reported that early life sleep disruption (ELSD) during the preweaning period results in interference with social bonding and increases ethanol consumption following a stressor in adulthood. Furthermore, ELSD increases parvalbumin expression and reduces glutamatergic neurotransmission in cortical regions in adult prairie voles. To understand the impact of ELSD on the lifespan, an examination of an earlier time in life is necessary. The aim of the present study was to examine behavioral outcomes of ELSD on adolescent prairie voles. Given the known effects of ELSD on development of neuronal systems involved in mood and social motivation, we hypothesized that anxiety, risk, and reward-related behaviors would be impacted by ELSD in adolescent prairie voles. We report that both male and female adolescent prairie voles that experienced ELSD showed heightened anxiety-like behavior compared to age-matched controls (CONs) as measured by a light-dark box. Additionally, both male and female ELSD voles showed reductions in both ethanol preference and consumption, and affiliative behavior compared to CONs. These results suggest that adolescent prairie voles of both sexes experience heightened anxiety-like behavior and reduced reward-seeking behaviors after ELSD. These results further suggest that early life sleep is critically important for neurotypical behaviors in adolescence.

Beyond Birth Control: The Neuroscience of Hormonal Contraceptives

Hormonal contraceptives (HCs) are one of the most highly prescribed classes of drugs in the world used for both contraceptive and noncontraceptive purposes. Despite their prevalent use, the impact of HCs on the brain remains inadequately explored. This review synthesizes recent findings on the neuroscience of HCs, with a focus on human structural neuroimaging as well as translational, nonhuman animal studies investigating the cellular, molecular, and behavioral effects of HCs. Additionally, we consider data linking HCs to mood disorders and dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis and stress response as a potential mediator. The review also addresses the unique sensitivity of the adolescent brain to HCs, noting significant changes in brain structure and function when HCs are used during this developmental period. Finally, we discuss potential effects of HCs in combination with smoking-derived nicotine on outcomes of ischemic brain damage. Methodological challenges, such as the variability in HC formulations and user-specific factors, are acknowledged, emphasizing the need for precise and individualized research approaches. Overall, this review underscores the necessity for continued interdisciplinary research to elucidate the neurobiological mechanisms of HCs, aiming to optimize their use and improve women's health.

Influence of socio-contextual factors on the link between traditional and new media use, and young people's sexual risk behaviour in Sub-Saharan Africa: a secondary data analysis

BACKGROUND

Traditional and new media use links to young people's sexual risk behaviour. The social contexts of young people's daily lives that influence media use and sexual risk behaviour are often investigated as independent causal mechanisms. We examined the link between media use and young people's sexual risk behaviour, considering the intersecting socio-contextual factors in Sub-Saharan Africa.

METHODS

Age-adjusted bivariate logistic regression models tested the association between traditional media (TV, radio, and newspapers), and new media (mobile phone and online) use and sexual risk behaviour using the Demographic and Health Surveys from six Sub-Saharan African countries among unmarried sexually active youths, aged 15-24 years. Multivariate logistic regression models ascertained the media sources that had an additional influence on young people's sexual risk behaviour, after accounting for socio-contextual factors, and knowledge about HIV and other sexually transmitted infections.

RESULTS

Socio-contextual factors attenuated the association between media use and young people's sexual risk behaviour in many countries. However, those who did not have access to new and traditional media were more likely to use unreliable contraceptive methods or not use contraception. Adolescents in Nigeria who did not own phones were 89% more likely to use unreliable contraceptive methods or not use any methods [(AOR = 1.89 (1.40-2.56), p < .001)], those in Angola who did not read newspapers had higher odds of not using contraception or used unreliable methods [(aOR = 1.65 (1.26-2.15), p < .001)]. Young people in Angola (aOR = 0.68 (0.56-0.83), p < .001), Cameroon [(aOR = 0.66 (0.51-0.84), p < .001)], Nigeria [(aOR = 0.72 (0.56-0.93), p = .01)], and South Africa [(aOR = 0.69 (0.49-0.98), p = .03)] who did not own phones were less likely to have 2 or more sexual partners compared to those who owned phones. Lack of internet access in Mali was associated with lower odds of having 2 or more sexual partners (aOR = 0.45 (0.29-0.70), p < .001). Traditional media use was significantly associated with transactional sex in many countries.

CONCLUSIONS

Media use is linked to sexual risk behaviour among young people in Sub-Saharan Africa. Socioeconomic inequalities, levels of globalization, as well as rural-urban disparities in access to media, underscore the need to deliver tailored and targeted sexual risk reduction interventions to young people using both traditional and new media.

Amygdala volume and depression symptoms in young adolescents who use cannabis

INTRODUCTION

Both cannabis use and depressive symptomology increase in prevalence throughout adolescence. Concurrently, the brain is undergoing neurodevelopment in important limbic regions, such as the amygdala. Prior research indicates the amygdala may also be related to cannabis use and depressive symptoms. We aimed to investigate the effects of adolescent cannabis use on amygdala volumes as well as the interaction of cannabis use and amygdala morphometry on depressive symptoms in youth.

METHOD

Two-hundred-twenty-four participants (ages 12-15), balanced by sex assigned at birth, were selected from a sub-sample of the Adolescent Brain Cognitive Development (ABCD) Study based on hair toxicology and self-report measures of cannabis use. Participants positive for cannabinoids in hair and/or self-reported cannabis use were demographically matched to youth with no self-reported or confirmed cannabis use. The guardians of these youth reported depression symptoms on the Child Behavioral Checklist. Linear mixed effect models were run investigating cannabis use group on amygdala volumes bilaterally, controlling for whole brain volume and random effects of scanner type. Additional analyses examined cannabis group status and bilateral amygdala volume on depression symptoms.

RESULTS

Cannabis use was not significantly associated with amygdala volume but was associated with increased depressive symptoms (p<0.01). Cannabis group interacted with amygdala volume, such that individuals with smaller volumes had increased depressive symptoms within the cannabis group (p's<0.01-0.02).

CONCLUSION

Aberrations in amygdala volume based on cannabis use were not found in early adolescence; however, more depressive symptoms were related to cannabis group. Youth who use cannabis and have smaller amygdala volumes were at increased risk for depressive symptomology, suggesting potential neurovulnerabilities to cannabis use.

Nicotine use during late adolescence and young adulthood is associated with changes in hippocampal volume and memory performance

Background

With the advent of electronic nicotine delivery systems, the use of nicotine and tobacco products (NTPs) among adolescents and young adults remains high in the US. Use of e-cigarettes additionally elevates the risk of problematic use of other substances like cannabis, which is often co-used with NTPs. However, their effects on brain health, particularly the hippocampus, and cognition during this neurodevelopmental period are poorly understood.

Methods

Healthy late adolescents/young adults (N = 223) ages 16-22 completed a structural MRI to examine right and left hippocampal volumes. Memory was assessed with the NIH Toolbox Picture Sequence Memory Test (PSMT) and Rey Auditory Verbal Learning Test (RAVLT). Cumulative 6-month NTP and cannabis episodes were assessed and modeled continuously on hippocampal volumes. Participants were then grouped based on 6-month NTP use to examine relationships with the hippocampus and memory: current users (CU) endorsed weekly or greater use; light/abstinent users (LU) endorsed less than weekly; and never users (NU).

Results

NTP use predicted larger hippocampal volumes bilaterally while cannabis use had no impact nor interacted with NTP use. For memory, larger left hippocampal volumes were positively associated with PSMT performance, RAVLT total learning, short delay and long delay recall for the NU group. In contrast, there was a negative relationship between hippocampal volumes and performances for LU and CU groups. No differences were detected between NTP-using groups.

Conclusion

These results suggest that the hippocampus is sensitive to NTP exposure during late adolescence/young adulthood and may alter typical hippocampal morphometry in addition to brain-behavior relationships underlying learning and memory processes.

Subregion-specific transcriptomic profiling of rat brain reveals sex-distinct gene expression impacted by adolescent stress

Stress during adolescence clearly impacts brain development and function. Sex differences in adolescent stress-induced or exacerbated emotional and metabolic vulnerabilities could be due to sex-distinct gene expression in hypothalamic, limbic, and prefrontal brain regions. However, adolescent stress-induced whole-genome expression changes in key subregions of these brain regions were unclear. In this study, female and male adolescent Sprague Dawley rats received one-hour restraint stress daily from postnatal day (PD) 32 to PD44. Corticosterone levels, body weights, food intake, body composition, and circulating adiposity and sex hormones were measured. On PD44, brain and blood samples were collected. Using RNA-sequencing, sex-specific differences in stress-induced differentially expressed (DE) genes were identified in subregions of the hypothalamus, limbic system, and prefrontal cortex. Canonical pathways reflected well-known sex-distinct maladies and diseases, substantiating the therapeutic potential of the DE genes found in the current study. Thus, we proposed specific sex distinct, adolescent stress-induced transcriptional changes found in the current study as examples of the molecular bases for sex differences witnessed in stress induced or exacerbated emotional and metabolic disorders. Future behavioral studies and single-cell studies are warranted to test the implications of the DE genes identified in this study in sex-distinct stress-induced susceptibilities.

Omega-3 fatty acids supplementation prevents learning and memory impairment induced by chronic ethanol consumption in adolescent male rats through restoration of inflammatory and oxidative responses

OBJECTIVE

Ethanol (Eth) intake is known to cause numerous detrimental effects on the structure and function of the brain, and it is commonly used as a psychostimulant drug by adolescents. Conversely, omega-3 (O3) can reduce the risk of cognitive decline and promote the maintenance of neurophysiological functions. In this study, we investigated the protective effects of O3 on behavioral alterations, oxidative stress, and interleukin-6 (IL-6) levels induced by chronic Eth intake during adolescence in rats.

MATERIALS AND METHODS

Adolescent male rats (21 days old) were divided as follows: (1) Vehicle, (2) Eth (Eth in drinking water [20%]), (3-5) Eth + O3 (50/100/150 mg/kg), and (6) O3 (150 mg/kg). After 5 weeks, Morris water maze (MWM) and passive avoidance (PA) tests were performed, and the hippocampal and cortical levels of oxidative stress markers and inflammatory indices were measured.

RESULTS

Adolescent Eth intake impairs learning and memory function in MWM and PA tests (groups × day, p < 0.05 and p < 0.001, respectively). It was shown that Eth induced oxidative stress and neuroinflammation. O3 improved learning and impairment induced by Eth by reducing the adverse effects of Eth on the oxidant/antioxidant balance in the hippocampi (for malondialdehyde [MDA]/thiol: p < 0.01, p < 0.001, respectively) and for superoxide dismutase (SOD)/catalase (CAT): p < 0.01 and p < 0.05, respectively). Furthermore, we found that O3 prevented the Eth-induced increase of hippocampal IL-6 (p < 0.001).

CONCLUSION

O3 supplementation acts as an effective approach to prevent learning and memory impairments induced by chronic Eth consumption during adolescence. In this respect, the antioxidant and anti-inflammatory properties of O3 seem to be the main underlying mechanisms of neuroprotection.

The roles of extraversion and neuroticism in the relationship between childhood adversity and adolescent substance misuse

Although the influences of extraversion and neuroticism on the relationship between childhood adversity and substance misuse have been considered in adults, they are not yet clear and have not been examined among adolescent samples. This study sought to investigate the relationship between childhood adversity and adolescent substance misuse, alongside the influences of extraversion and neuroticism, using data from a longitudinal birth cohort study. Statistical analyses were performed on a longitudinal dataset provided by the Christchurch Health and Development Study (CHDS). After controlling for confounds, childhood adversity was a significant predictor of substance use disorder symptoms in adolescence. Moderation analyses showed that experiences of childhood adversity were most strongly associated with adolescent substance use disorder symptoms at higher levels of extraversion and at higher levels of neuroticism. Among adolescents who have experienced childhood adversity, extraversion and neuroticism may be risk factors for substance use disorder. By encouraging professionals to target adolescent substance misuse intervention and prevention approaches towards those who have experienced childhood adversity and are high in extraversion and/or neuroticism, these findings may help to diminish the prevalence of adolescent substance misuse and improve the health of adolescents.

Altered learning from positive feedback in adolescents with anorexia nervosa

OBJECTIVE

Anorexia nervosa (AN) is characterized by severe restriction of calorie intake, which persists despite serious medical and psychological sequelae of starvation. Several prior studies have identified impaired feedback learning among individuals with AN, but whether it reflects a disturbance in learning from positive feedback (i.e., reward), negative feedback (i.e., punishment), or both, and the extent to which this impairment is related to severity and duration of illness, has not been clarified.

METHOD

Participants were female adolescents with AN (n = 76) and healthy teen volunteers (HC; n = 38) between the ages of 12-18 years who completed a probabilistic reinforcement learning task. A Bayesian reinforcement learning model was used to calculate separate learning rates for positive and negative feedback. Exploratory analyses examined associations between feedback learning and duration of illness, eating disorder severity, and self/parent reports of reward and punishment sensitivity.

RESULTS

Adolescents with AN had a significantly lower rate of learning from positive feedback relative to HC. Patients and HC did not differ in learning from negative feedback or on overall task performance measures. Feedback learning parameters were not significantly associated with duration of illness, eating disorder severity, or questionnaire-based reports of reward and punishment sensitivity.

CONCLUSION

Adolescents with AN showed a circumscribed deficit in learning from reward that was not associated with duration of illness or reported sensitivity to reward or punishment. Subsequent longitudinal research should explore whether differences in learning from positive feedback relate to course of illness in youth with AN.

The role of β-Nicotyrine in E-Cigarette abuse liability I: Drug Discrimination

Background

β-Nicotyrine (β-Nic) is a unique minor alkaloid constituent in electronic nicotine delivery systems (ENDS) that is derived from nicotine (Nic) degradation and can reach 25% of Nic concentrations in ENDS aerosol. β-Nic slows Nic metabolism and prolongs systemic Nic exposure, which may alter the discriminability of Nic. The present study sought to examine β-Nic has interoceptive effects itself, and if it alters the subjective effects ENDS products within a drug-discrimination paradigm.

Methods

The pharmacodynamics of β-Nic were examined in vitro, and a nicotine discrimination paradigm was used to determine if β-Nic (0 - 5.0 mg/kg) shares discriminative stimulus properties with Nic (0.2 mg/kg) in male (n = 13) and female (n = 14) rats after 10- & 60-min β-Nic pretreatment delays. A second group of rats was trained to discriminate β-Nic and Nornicotine (Nornic) from saline to determine if β-Nic alone has interoceptive properties and whether they are similar to Nornic.

Results

β-Nic had similar binding affinity and efficacy at the α4β2 nicotinic receptor subtype as Nornic, ~50% of Nic efficacy. However, β-Nic only weakly substituted for Nic during substitution testing in female rats, but not males, whereas Nornic fully substituted for Nic. Combination testing at the 10 and 60-min pretreatment intervals showed that β-Nic dose-dependently increased the duration of nicotine's discriminative stimulus effects, especially at the 60-min delay. Drug naïve rats could reliably discriminate Nornic, but not β-Nic, from Sal.

Conclusion

β-Nic increased and prolonged the interoceptive stimulus properties of Nic, suggesting it may alter to the abuse liability of ENDS through its ability to slow Nic metabolism.

Coprococcus eutactus screened from healthy adolescent attenuates chronic restraint stress-induced depression-like changes in adolescent mice: Potential roles in the microbiome and neurotransmitter modulation

The onset of depression commonly occurs in adolescence; therefore, depressive prevention and intervention are pivotal during this period. It is becoming evident that neurotransmitter imbalance and gut microbiota dysbiosis are prominent causes of depression. However, the underlying links and mechanisms remain poorly understood. In this study, with 16S ribosomal RNA gene sequencing, genus Coprococcus markedly differentiated between the healthy and unmedicated depressive adolescents. Based on this, transplantation of Coprococcus eutactus (C.e.) was found to dramatically ameliorate the chronic restraint stress (CRS) induced depression-like changes and prevent synaptic loss and glial-stimulated neuroinflammation in mice. The Ultra-high performance liquid chromatography tandem mass spectrometry analysis (UHPLC-MS/MS) further showed that neurotoxic neurotransmitters in kynurenine pathway (KP) such as 3-hydroxykynurenine (3-HK) and 3-hydroxyanthranilic acid (3-HAA) decreased in mouse brains, mechanistically deciphering the transfer of the tryptophan metabolic pathway to serotonin metabolic signaling in the brain after C.e. treatment, which was also verified in the colon. Molecularly, blockage of KP activities mediated by C.e. was ascribed to the restraint of the limit-step enzymes responsible for kynurenine, 3-HK, and quinolinic acid generation. In the colon, C.e. treatment significantly recovered goblet cells and mucus secretion in CRS mice which may ascribe to the rebalance of the disordered gut microbiota, especially Akkermansia, Roseburia, Rikenella, Blautia, and Alloprevotella. Taken together, the current study reveals for the first time the beneficial effects and potential mechanisms of C.e. in ameliorating CRS-induced depression, unraveling the direct links between C.e. treatment and neurotransmitter rebalance, which may provide efficacious therapeutic avenues for adolescent depressive intervention.

A unique multi-synaptic mechanism involving acetylcholine and GABA regulates dopamine release in the nucleus accumbens through early adolescence in male rats

Adolescence is characterized by changes in reward-related behaviors, social behaviors, and decision-making. These behavioral changes are necessary for the transition into adulthood, but they also increase vulnerability to the development of a range of psychiatric disorders. Major reorganization of the dopamine system during adolescence is thought to underlie, in part, the associated behavioral changes and increased vulnerability. Here, we utilized fast scan cyclic voltammetry and microdialysis to examine differences in dopamine release as well as mechanisms that underlie differential dopamine signaling in the nucleus accumbens (NAc) core of adolescent (P28-35) and adult (P70-90) male rats. We show baseline differences between adult and adolescent-stimulated dopamine release in male rats, as well as opposite effects of the α6 nicotinic acetylcholine receptor (nAChR) on modulating dopamine release. The α6-selective blocker, α-conotoxin, increased dopamine release in early adolescent rats, but decreased dopamine release in rats beginning in middle adolescence and extending through adulthood. Strikingly, blockade of GABAA and GABAB receptors revealed that this α6-mediated increase in adolescent dopamine release requires NAc GABA signaling to occur. We confirm the role of α6 nAChRs and GABA in mediating this effect in vivo using microdialysis. Results herein suggest a multisynaptic mechanism potentially unique to the period of development that includes early adolescence, involving acetylcholine acting at α6-containing nAChRs to drive inhibitory GABA tone on dopamine release.

The impact of suppressing puberty on neuropsychological function: A review

AIM

Concerns have been raised regarding the impact of medications that interrupt puberty, given the magnitude and complexity of changes that occur in brain function and structure during this sensitive window of neurodevelopment. This review examines the literature on the impact of pubertal suppression on cognitive and behavioural function in animals and humans.

METHODS

All studies reporting cognitive impacts of treatment with GnRH agonists/antagonists for pubertal suppression in animals or humans were sought via a systematic search strategy across the PubMed, Embase, Web of Science and PsycINFO databases.

RESULTS

Sixteen studies were identified. In mammals, the neuropsychological impacts of puberty blockers are complex and often sex specific (n = 11 studies). There is no evidence that cognitive effects are fully reversible following discontinuation of treatment. No human studies have systematically explored the impact of these treatments on neuropsychological function with an adequate baseline and follow-up. There is some evidence of a detrimental impact of pubertal suppression on IQ in children.

CONCLUSION

Critical questions remain unanswered regarding the nature, extent and permanence of any arrested development of cognitive function associated with puberty blockers. The impact of puberal suppression on measures of neuropsychological function is an urgent research priority.

Navigating Pubertal Goldilocks: The Optimal Pace for Hierarchical Brain Organization

Adolescence is a timed process with an onset, tempo, and duration. Nevertheless, the temporal dimension, especially the pace of maturation, remains an insufficiently studied aspect of developmental progression. The primary objective is to estimate the precise influence of pubertal maturational tempo on the configuration of associative brain regions. To this end, the connection between maturational stages and the level of hierarchical organization of large-scale brain networks in 12-13-year-old females is analyzed. Skeletal maturity is used as a proxy for pubertal progress. The degree of maturity is defined by the difference between bone age and chronological age. To assess the level of hierarchical organization in the brain, the temporal dynamic of closed eye resting state high-density electroencephalography (EEG) in the alpha frequency range is analyzed. Different levels of hierarchical order are captured by the measured asymmetry in the directionality of information flow between different regions. The calculated EEG-based entropy production of participant groups is then compared with accelerated, average, and decelerated maturity. Results indicate that an average maturational trajectory optimally aligns with cerebral hierarchical order, and both accelerated and decelerated timelines result in diminished cortical organization. This suggests that a "Goldilocks rule" of brain development is favoring a particular maturational tempo.

Psychosocial risk and protective factors for youth problem behavior are associated with food addiction in the Generation Z

Objective

Food Addiction (FA) and other well-known risk behavior as substance misuse tend to co-occur and may share similar risk and protective factors. The aim of this study was to assess the association between the diagnosis/severity of FA and psychosocial domains typically related to risk behavior syndrome in a large, nationally representative community sample of Generation Z underage Italian students.

Method

The sample consisted of 8,755 students (3,623 from middle schools, 5,132 from high schools). A short version of the Yale Food Addiction Scale 2.0 was administered to evaluate FA. Risk and protective factors related to demographic, personality, behavior, and family variables were examined. Stepwise multivariate logistic and linear regressions were conducted.

Results

The prevalence of FA was 30.8%. Female gender, social anxiety and depression symptoms, social withdrawal risk, Internet gaming disorder, social media addiction, current substance use, social challenge engagement and experienced doxing boosted the chance of FA diagnosis, whereas eating fruit and vegetables, playing competitive sports and an average sleep duration of 7-8 h per night reduced these odds. FA severity was significantly and positively associated with trait impulsiveness, social anxiety and depressive symptoms, risk of social withdrawal, recent substance use, social media, and gaming addiction, doxing suffered and risky social challenges participation. Negative associations between the severity of FA and fruit and vegetable diet habits were found.

Conclusion

Our findings confirm that FA is widespread among Italian adolescents. The associations between the diagnosis and severity of FA and psychosocial risk factors for health, including, addictive and deviant behaviors related to digital misuse, suggest its belonging to the risk behavior constellation. Health promotion schemes based on a multicomponent strategy of intervention should consider the inclusion of FA and its psychosocial correlates.

Cortical grey matter volume differences in children with developmental coordination disorder compared to typically developing children

Introduction

The cause of Developmental Coordination Disorder (DCD) is unknown, but neuroimaging evidence suggests that DCD may be related to altered brain development. Children with DCD show less structural and functional connectivity compared to typically developing (TD) children, but few studies have examined cortical volume in children with DCD. The purpose of this study was to investigate cortical grey matter volume using voxel-based morphometry (VBM) in children with DCD compared to TD children.

Methods

This cross-sectional study was part of a larger randomized-controlled trial (ClinicalTrials.gov ID: NCT02597751) that involved various MRI scans of children with/without DCD. This paper focuses on the anatomical scans, performing VBM of cortical grey matter volume in 30 children with DCD and 12 TD children. Preprocessing and VBM data analysis were conducted using the Computational Anatomy Tool Box-12 and a study-specific brain template. Differences between DCD and TD groups were assessed using a one-way ANOVA, controlling for total intracranial volume. Regression analyses examined if motor and/or attentional difficulties predicted grey matter volume. We used threshold-free cluster enhancement (5,000 permutations) and set an alpha level of 0.05. Due to the small sample size, we did not correct for multiple comparisons.

Results

Compared to the TD group, children with DCD had significantly greater grey matter in the left superior frontal gyrus. Lower motor scores (meaning greater impairment) were related to greater grey matter volume in left superior frontal gyrus, frontal pole, and right middle frontal gyrus. Greater grey matter volume was also significantly correlated with higher scores on the Conners 3 ADHD Index in the left superior frontal gyrus, superior parietal lobe, and precuneus. These results indicate that greater grey matter volume in these regions is associated with poorer motor and attentional skills.

Discussion

Greater grey matter volume in the left superior frontal gyrus in children with DCD may be a result of delayed or absent healthy cortical thinning, potentially due to altered synaptic pruning as seen in other neurodevelopmental disorders. These findings provide further support for the hypothesis that DCD is related to altered brain development.