Adolescent Brain Development and Contextual Influences: A Decade in Review

The beautiful adolescent brain: An evolutionary developmental perspective

The adolescent brain has been characterized as a defective car, with no brakes or steering wheel-only an accelerator. This characterization has been used to explain the impulsive and risky behavior of this transient developmental period. But why do adolescents respond to the world the way they do? In this article, we consider adolescent-specific changes in the brain and behavior from a developmental evolutionary viewpoint in how they might be adaptive. We suggest ways in which the adolescent brain has evolved to explore and learn from new and changing environments as the adolescent gains independence from the caregiver and transitions into an adult. We highlight adolescent-specific changes in the brain and behavior in response to emotional and social cues that may facilitate learning to independently secure resources (e.g., food, water, and shelter) and to establish new social bonds beyond the family or pack for their own survival. Specifically, we focus on how rewards, social cues, and threats in the environment influence behavior and may serve an adaptive role for the adolescent.

Transcendent thinking counteracts longitudinal effects of mid-adolescent exposure to community violence in the anterior cingulate cortex

Adolescence involves extensive brain maturation, characterized by social sensitivity and emotional lability, that co-occurs with increased independence. Mid-adolescence is also a hallmark developmental stage when youths become motivated to reflect on the broader personal, ethical, and systems-level implications of happenings, a process we term transcendent thinking. Here, we examine the confluence of these developmental processes to ask, from a transdisciplinary perspective, how might community violence exposure (CVE) impact brain development during mid-adolescence, and how might youths' dispositions for transcendent thinking be protective? Fifty-five low-SES urban youth with no history of delinquency (32 female; 27 Latinx, 28 East Asian) reported their CVE and underwent structural MRI first at age 14-18, and again 2 years later. At the study's start, participants also discussed their feelings about 40 minidocumentaries featuring other teens' compelling situations in a 2-h private interview that was transcribed and coded for transcendent thinking. Controlling for CVE and brain structure at the start: (1) New CVE during the 2-year inter-scan interval was associated with greater gray matter volume (GMV) reduction over that interval in the anterior cingulate cortex (ACC), a central network hub whose reduced volume has been associated with posttraumatic stress disorder, and across multiple additional cortical and subcortical regions; (2) participants' transcendent thinking in the interview independently predicted greater GMV increase during the 2-year inter-scan interval in the ACC. Findings highlight the continued vulnerability of mid-adolescents to community violence and the importance of supporting teens' dispositions to reflect on the complex personal and systems-level implications and affordances of their civic landscape.

Training on Inpatient Child and Adolescent Psychiatry Units

Child and adolescent psychiatry (CAP) inpatient units are a common site in academic settings for trainee education. The authors review the foundational aspects of education that should be covered during these rotations. Trainees should begin with a solid foundation of child and adolescent development and learn how this impacts risk assessment, formulation, and treatment planning. In addition, the authors review milieu considerations, agitation management, legal considerations, family involvement, systems of care, trainee supervision, transference, countertransference, and the Accreditation Council for Graduate Medical Education requirements as they relate to resident and fellow education on a CAP inpatient unit.

The role (and limits) of developmental neuroscience in determining adolescents' autonomy rights: The case for reproductive and voting rights

Neuroscientific evidence documenting continued neural development throughout adolescence has been leveraged in advocacy for more lenient treatment of adolescents in the criminal justice system. In recent years, developmental science, including neuroscience, has progressed and enabled more nuanced interpretations of what continuing neural development in adolescence likely means functionally for adolescents' capabilities. However, oversimplified interpretations equating continuing neural development to overall "immaturity" are frequently used to make the case that adolescents should have fewer legal rights to make decisions on their own behalf, including regarding reproductive and voting rights. Here we address ongoing debates about adolescents' autonomy rights and whether such rights should be expanded or restricted. We review extant neuroscientific and developmental research that can inform these debates. We call for: (1) a more nuanced application of developmental neuroscience to specific rights issues in specific contexts; (2) additional research designed to inform our understanding of the developmental benefits or harms of rights-based policies on young people over time; and (3) the grounding of developmental neuroscientific research on adolescents within a human rights framework. We offer suggestions to developmental and neuroscience scholars on how to discuss the science of adolescent development with those seeking guidance in their design of law and policy.

Associations between Fine Particulate Matter Components, Their Sources, and Cognitive Outcomes in Children Ages 9-10 Years Old from the United States

BACKGROUND

Emerging literature suggests that fine particulate matter [with aerodynamic diameter ≤ 2.5 μ m (PM 2.5 )] air pollution and its components are linked to various neurodevelopmental outcomes. However, few studies have evaluated how PM 2.5 component mixtures from distinct sources relate to cognitive outcomes in children.

OBJECTIVES

This cross-sectional study investigated how ambient concentrations of PM 2.5 component mixtures relate to neurocognitive performance in 9- to 10-year-old children, as well as explored potential source-specific effects of these associations, across the US.

METHODS

Using spatiotemporal hybrid models, annual concentrations of 15 chemical components of PM 2.5 were estimated based on the residential address of child participants from the Adolescent Brain Cognitive Development (ABCD) Study. General cognitive ability, executive function, and learning/memory scores were derived from the NIH Toolbox. We applied positive matrix factorization to identify six major PM 2.5 sources based on the 15 components, which included crustal, ammonium sulfate, biomass burning, traffic, ammonium nitrate, and industrial/residual fuel burning. We then utilized weighted quantile sum (WQS) and linear regression models to investigate associations between PM 2.5 components' mixture, their potential sources, and children's cognitive scores.

RESULTS

Mixture modeling revealed associations between cumulative exposure and worse cognitive performance across all three outcome domains, including shared overlap in detrimental effects driven by ammonium nitrates, silicon, and calcium. Using the identified six sources of exposure, source-specific negative associations were identified between ammonium nitrates and learning & memory, traffic and executive function, and crustal and industrial mixtures and general cognitive ability. Unexpected positive associations were also seen between traffic and general ability as well as biomass burning and executive function.

DISCUSSION

This work suggests nuanced associations between outdoor PM 2.5 exposure and childhood cognitive performance, including important differences in cognition related both to individual chemicals as well as to specific sources of these exposures. https://doi.org/10.1289/EHP14418.

Socioeconomic Disadvantage Moderates the Association of Systemic Inflammation With Amygdala Volume in Adolescents Over a 2-Year Interval: An Exploratory Study

BACKGROUND

Research has demonstrated an association between elevated systemic inflammation and changes in brain function. Affective areas of the brain involved in processing threat (e.g., amygdala) and reward (e.g., nucleus accumbens) appear to be sensitive to inflammation. Early-life stress, such as experiencing low socioeconomic status (SES), may also potentiate this association, but relevant evidence has come primarily from cross-sectional studies of brain function. It is unclear whether similar associations are present between early-life stress, inflammation, and brain structure, particularly in typically developing populations.

METHODS

We recruited and assessed 50 adolescents (31 females/19 males) from the community (mean [SD] age = 15.5 [1.1] years, range = 13.1-17.5 years) and examined in exploratory analyses whether changes in C-reactive protein (ΔCRP) from blood spots predict changes in gray matter volume (ΔGMV) in the bilateral amygdala and nucleus accumbens over a 2-year period. We also investigated whether experiencing early-life stress, operationalized using a comprehensive composite score of SES disadvantage at the family and neighborhood levels, significantly moderated the association between ΔCRP and ΔGMV.

RESULTS

We found that ΔCRP was negatively associated with Δamygdala GMV (i.e., increasing CRP levels were associated with decreasing amygdala volume; β = -0.84, p = .012). This effect was stronger in youths who experienced greater SES disadvantage (β = -0.56, p = .025).

CONCLUSIONS

These findings suggest that increases in systemic inflammation are associated with reductions in amygdala GMV in adolescents, potentially signaling accelerated maturation, and that these neuroimmune processes are compounded in adolescents who experienced greater SES disadvantage. Our findings are consistent with theoretical frameworks of neuroimmune associations and suggest that they may influence adolescent neurodevelopment.

Altered neural anticipation of reward and loss but not receipt in adolescents with obsessive-compulsive disorder

BACKGROUND

Obsessive-compulsive disorder (OCD) is characterized by persistent, unwanted thoughts and repetitive actions. Such repetitive thoughts and/or behaviors may be reinforced either by reducing anxiety or by avoiding a potential threat or harm, and thus may be rewarding to the individual. The possible involvement of the reward system in the symptomatology of OCD is supported by studies showing altered reward processing in reward-related regions, such as the ventral striatum (VS) and the orbitofrontal cortex (OFC), in adults with OCD. However, it is not clear whether this also applies to adolescents with OCD.

METHODS

Using functional magnetic resonance imaging, two sessions were conducted focusing on the anticipation and receipt of monetary reward (1) or loss (2), each contrasted to a verbal (control) condition. In each session, adolescents with OCD (n1=31/n2=26) were compared with typically developing (TD) controls (n1=33/ n2=31), all aged 10-19 years, during the anticipation and feedback phase of an adapted Monetary Incentive Delay task.

RESULTS

Data revealed a hyperactivation of the VS, but not the OFC, when anticipating both monetary reward and loss in the OCD compared to the TD group.

CONCLUSIONS

These findings suggest that aberrant neural reward and loss processing in OCD is associated with greater motivation to gain or maintain a reward but not with the actual receipt. The greater degree of reward 'wanting' may contribute to adolescents with OCD repeating certain actions more and more frequently, which then become habits (i.e., OCD symptomatology).

Diverse adolescents' transcendent thinking predicts young adult psychosocial outcomes via brain network development

Developmental scientists have long described mid-adolescents' emerging capacities to make deep meaning about the social world and self, here called transcendent thinking, as a hallmark developmental stage. In this 5-years longitudinal study, sixty-five 14-18 years-old youths' proclivities to grapple psychologically with the ethical, systems-level and personal implications of social stories, predicted future increases in the coordination of two key brain networks: the default-mode network, involved in reflective, autobiographical and free-form thinking, and the executive control network, involved in effortful, focused thinking; findings were independent of IQ, ethnicity, and socioeconomic background. This neural development predicted late-adolescent identity development, which predicted young-adult self-liking and relationship satisfaction, in a developmental cascade. The findings reveal a novel predictor of mid-adolescents' neural development, and suggest the importance of attending to adolescents' proclivities to engage agentically with complex perspectives and emotions on the social and personal relevance of issues, such as through civically minded educational approaches.

Early life stress moderates the relation between systemic inflammation and neural activation to reward in adolescents both cross-sectionally and longitudinally

Elevated levels of systemic inflammation are associated with altered reward-related brain function in ventral striatal areas of the brain like the nucleus accumbens (NAcc). In adolescents, cross-sectional research indicates that exposure to early life stress (ELS) can moderate the relation between inflammation and neural activation, which may contribute to atypical reward function; however, no studies have tested whether this moderation by ELS of neuroimmune associations persists over time. Here, we conducted a cross-sectional analysis and the first exploratory longitudinal analysis testing whether cumulative severity of ELS moderates the association of systemic inflammation with reward-related processing in the NAcc in adolescents (n = 104; 58F/46M; M[SD] age = 16.00[1.45] years; range = 13.07-19.86 years). For the cross-sectional analysis, we modeled a statistical interaction between ELS and levels of C-reactive protein (CRP) predicting NAcc activation during the anticipation and outcome phases of a monetary reward task. We found that higher CRP was associated with blunted NAcc activation during the outcome of reward in youth who experienced higher levels of ELS (β = -0.31; p = 0.006). For the longitudinal analysis, we modeled an interaction between ELS and change in CRP predicting change in NAcc activation across 2 years. This analysis similarly showed that increasing CRP over time was associated with decreasing NAcc during reward outcomes in youth who experienced higher levels of ELS (β = -0.47; p = 0.022). Both findings support contemporary theoretical frameworks involving associations among inflammation, reward-related brain function, and ELS exposure, and suggest that experiencing ELS can have significant and enduring effects on neuroimmune function and adolescent neurodevelopment.

Promoting positive development among refugee adolescents

Of the estimated 35.3 million refugees around the world (UNHCR, Figures at a Glance, 2022), approximately 50% are children under the age of 18. Refugee adolescents represent a unique group as they navigate developmental tasks in an unstable and often threatening environment or in resettlement contexts in which they often face marginalization. In addition to physiological, social, and psychological changes that mark adolescence, refugee youth often face traumatic experiences, acculturative stress, discrimination, and a lack of basic resources. In this consensus statement, we examine research on refugee adolescents' developmental tasks, acculturative tasks, and psychological adjustment using Suárez-Orozco and colleague's integrative risk and resilience model for immigrant-origin children and youth proposed by Suárez-Orozco et al. Finally, we discuss recommendations-moving from proximal to more distal contexts.

Associations between alcohol use and sex-specific maturation of subcortical gray matter morphometry from adolescence to adulthood: Replication across two longitudinal samples

Subcortical brain morphometry matures across adolescence and young adulthood, a time when many youth engage in escalating levels of alcohol use. Initial cross-sectional studies have shown alcohol use is associated with altered subcortical morphometry. However, longitudinal evidence of sex-specific neuromaturation and associations with alcohol use remains limited. This project used generalized additive mixed models to examine sex-specific development of subcortical volumes and associations with recent alcohol use, using 7 longitudinal waves (n = 804, 51% female, ages 12-21 at baseline) from the National Consortium on Alcohol and Neurodevelopment in Adolescence (NCANDA). A second, independent, longitudinal dataset, with up to four waves of data (n = 467, 43% female, ages 10-18 at baseline), was used to assess replicability. Significant, replicable non-linear normative volumetric changes with age were evident in the caudate, putamen, thalamus, pallidum, amygdala and hippocampus. Significant, replicable negative associations between subcortical volume and alcohol use were found in the hippocampus in all youth, and the caudate and thalamus in female but not male youth, with significant interactions present in the caudate, thalamus and putamen. Findings suggest a structural vulnerability to alcohol use, or a predisposition to drink alcohol based on brain structure, with female youth potentially showing heightened risk, compared to male youth.

Neural responses to reward valence and magnitude from pre- to early adolescence

BACKGROUND

Neural activation during reward processing is thought to underlie critical behavioral changes that take place during the transition to adolescence (e.g., learning, risk-taking). Though literature on the neural basis of reward processing in adolescence is booming, important gaps remain. First, more information is needed regarding changes in functional neuroanatomy in early adolescence. Another gap is understanding whether sensitivity to different aspects of the incentive (e.g., magnitude and valence) changes during the transition into adolescence. We used fMRI from a large sample of preadolescent children to characterize neural responses to incentive valence vs. magnitude during anticipation and feedback, and their change over a period of two years.

METHODS

Data were taken from the Adolescent Cognitive and Brain DevelopmentSM (ABCD®) study release 3.0. Children completed the Monetary Incentive Delay task at baseline (ages 9-10) and year 2 follow-up (ages 11-12). Based on data from two sites (N = 491), we identified activation-based Regions of Interest (ROIs; e.g., striatum, prefrontal regions, etc.) that were sensitive to trial type (win $5, win $0.20, neutral, lose $0.20, lose $5) during anticipation and feedback phases. Then, in an independent subsample (N = 1470), we examined whether these ROIs were sensitive to valence and magnitude and whether that sensitivity changed over two years.

RESULTS

Our results show that most ROIs involved in reward processing (including the striatum, prefrontal cortex, and insula) are specialized, i.e., mainly sensitive to either incentive valence or magnitude, and this sensitivity was consistent over a 2-year period. The effect sizes of time and its interactions were significantly smaller (0.002≤η2≤0.02) than the effect size of trial type (0.06≤η2≤0.30). Interestingly, specialization was moderated by reward processing phase but was stable across development. Biological sex and pubertal status differences were few and inconsistent. Developmental changes were mostly evident during success feedback, where neural reactivity increased over time.

CONCLUSIONS

Our results suggest sub-specialization to valence vs. magnitude within many ROIs of the reward circuitry. Additionally, in line with theoretical models of adolescent development, our results suggest that the ability to benefit from success increases from pre- to early adolescence. These findings can inform educators and clinicians and facilitate empirical research of typical and atypical motivational behaviors during a critical time of development.

Sensitivity and specificity in affective and social learning in adolescence

Adolescence is a period of heightened affective and social sensitivity. In this review we address how this increased sensitivity influences associative learning. Based on recent evidence from human and rodent studies, as well as advances in computational biology, we suggest that, compared to other age groups, adolescents show features of heightened Pavlovian learning but tend to perform worse than adults at instrumental learning. Because Pavlovian learning does not involve decision-making, whereas instrumental learning does, we propose that these developmental differences might be due to heightened sensitivity to rewards and threats in adolescence, coupled with a lower specificity of responding. We discuss the implications of these findings for adolescent mental health and education.

Reappraising the role of dopamine in adolescent risk-taking behavior

Adolescence is characterized by increased risk-taking, which is often ascribed to developmental changes in dopaminergic signaling. Popular models propose that these behaviors are caused by dopamine-induced hypersensitivity to rewards, which overrides adolescents' immature self-control mechanisms. However, these models are often based on oversimplified notions about the workings and functions of dopamine. Here we discuss the relationship between changes in the dopaminergic system and adolescent behavior in light of current theories/models about the functions of dopamine. We show that dopamine is linked to learning, adaptive decision-making under uncertainty, and increased motivation to work for rewards. Thus, changes in the dopaminergic system contribute to the maturation of cognitive control through various mechanisms, contrary to the false dichotomy between reward processing and self-control. Finally, we note that dopamine interacts with a number of other neuromodulator systems, which also change during adolescence, but that have been largely ignored in the field of adolescent development. A full understanding of adolescent behavior will require these neurochemicals and their interactions with dopamine to be taken into account.

Dynamic cognitive inhibition in the context of frustration: Increasing racial representation of adolescent athletes using mobile community-engaged EEG methods

Introduction

Concussive events and other brain injuries are known to reduce cognitive inhibition, a key aspect of cognition that supports ones' behaviors and impacts regulation of mood or affect. Our primary objective is to investigate how induction of negative affect (such as frustration) impacts cognitive inhibition and the dynamic process by which youth athletes modulate responses. Secondary objective is to address the lack of Black representation in the scientific literature that promotes brain health and investigates pediatric sports-related brain injury. In particular, neuroscience studies predominantly include White participants despite broad racial representation in sport, in part due to technological hurdles and other obstacles that challenge research access for Black participants.

Methods

Using electroencephalography (EEG), we evaluate the dynamic brain processes associated with cognitive inhibition in the context of frustration induction in adolescent athletes during pre-season conditioning (i.e., prior to contact; N = 23) and a subset during post-season (n = 17).

Results

The N2 component was sensitive to frustration induction (decreased N2 amplitude, slower N2 latency), although effects were less robust at postseason. Trial-by-trial changes indicated a steady decrease of the N2 amplitude during the frustration block during the preseason visit, suggesting that affective interference had a dynamic effect on cognitive inhibition. Lastly, exploratory analyses provide preliminary evidence that frustration induction was less effective for athletes with a previous history of concussion or migraines (trending result) yet more effective for athletes endorsing a history with mental health disorders.

Discussion

We emphasize the urgent need to improve representation in cognitive neuroscience, particularly as it pertains to brain health. Importantly, we provide detailed guides to our methodological framework and practical suggestions to improve representative participation in studies utilizing high-density mobile EEG.