Development of Multifaceted Risk Taking and the Relations to Sex Steroid Hormones: A Longitudinal Study

Puberty and ADHD: A scoping review and framework for future research

Individuals with ADHD may experience puberty differently from their peers, which has implications for their health and wellbeing. This scoping review characterised and summarised literature reporting quantitative analyses of puberty and ADHD. To identify studies, nine databases (MEDLINE Complete, Web of Science, Embase, PsycInfo, ERIC, CENTRAL, PsycExtra, WHO ICTRP, and ProQuest Dissertations & Theses) were searched using key terms related to puberty/pubertal hormones and ADHD/ADHD traits. From 2795 initial records, 89 studies were eligible. Relevant analyses in included studies were categorised under five topics: 1) pubertal group comparisons between participants with ADHD and control participants; 2) associations between puberty and ADHD; 3) prevalence of ADHD in atypical puberty conditions; 4) ADHD medication effects on puberty; and 5) puberty and co-occurring psychological conditions. With some exceptions, summarised findings for each topic were generally inconsistent, indicating further well-planned primary studies are needed. A framework for future research is provided, recommending methodological improvements, including use of approaches that capture the complexities of puberty and ADHD, more inclusive sampling, and employing theories/models that recognise dynamics between puberty, psychological, social, and other biological factors. Additionally, it is recommended that research priorities in this area are identified in collaboration with key stakeholders, especially the ADHD community.

The Impact of Adverse Childhood Experiences on the Development of Adolescent Risk-Taking: The Mediating Effect of Self-Control and Moderating Effect of Genetic Variations

Risk-taking is a concerning yet prevalent issue during adolescence and can be life-threatening. Examining its etiological sources and evolving pathways helps inform strategies to mitigate adolescents' risk-taking behavior. Studies have found that unfavorable environmental factors, such as adverse childhood experiences (ACEs), are associated with momentary levels of risk-taking in adolescents, but little is known about whether ACEs shape the developmental trajectory of risk-taking. Even less research has investigated the underlying mechanisms. Drawing on the self-regulation theory, this study examined the associations between ACEs and the developmental trajectory of adolescent risk-taking. Moreover, it also explored self-control as a mediator and genetic variations as a moderator from a "gene × environment" approach. Participants were 564 Chinese adolescents (48.40% males, Mage = 14.20 years, SD = 1.52). Adolescents reported their ACEs and self-control at T1 and risk-taking three times, with a six-month interval between each time point. Adolescents' saliva was collected at T1 for genetic extraction, and polygenetic index was created based on the gene-by-environment interaction between SNPs and ACEs for self-control via the leave-one-out machine learning approach. Findings of latent growth modeling revealed that adolescents' risk-taking decreased over time. ACEs were directly and indirectly through self-control associated with high initial levels of, and a rapid decrease in, risk-taking, especially for those with a higher polygenetic index compared to those with a lower polygenetic index. Theoretically, these results suggest a tripartite model of adolescent risk-taking, such that risk-taking is the combined function of adverse experiences in early years, low self-control, and carriage of sensitive genes. Practically, intervention strategies should reduce childhood adversities, build up self-control, and consider the potential impacts of genetic plasticity.

Delay discounting in adolescence depends on whom you wait for: Evidence from a functional neuroimaging study

With age, adolescents increasingly demonstrate the ability to forgo immediate, smaller rewards in favor of larger delayed rewards, indicating reduced delay discounting. Adolescence is also a time of social reorientation, where decisions not only involve weighing immediate against future outcomes, but also consequences for self versus those for others. In this functional Magnetic Resonance Imaging study, we examined the neural correlates of immediate and delayed reward choices where the delayed outcomes could benefit self, friends, or unknown others. A total of 196 adolescent twins aged 14-17 completed a social delay discounting task, with fMRI data acquired from 174 participants. Out of these, 156 adolescents had valid fMRI data, and 138 adolescents had observations in every condition. Adolescents more often chose the immediate reward when it was larger, and when the delay was longer. Area-under-the-curve (AUC) comparisons revealed that behavior differed across delay-beneficiaries, with AUC being highest for the self, followed by friends, and lowest for unknown others. This suggests that adolescents are more willing to wait for rewards for self. Neuroimaging analyses showed increased activity in the midline areas medial prefrontal cortex (MPFC) and precuneus, as well as bilateral temporal parietal junction (TPJ) when considering delayed reward for unknown others and friends compared to self. A whole-brain interaction with choice showed that the bilateral insula and right dorsolateral prefrontal cortex (DLPFC) were more active for delayed choices for unknown others and for immediate choices for friends and self. This underscores that the neuro-cognitive processing of how delays reduce the value of rewards depends on closeness of the beneficiary.

Development of Self-Concept in Childhood and Adolescence: How Neuroscience Can Inform Theory and Vice Versa

How do we develop a stable and coherent self-concept in contemporary times? Susan Harter's original work, The Construction of Self (1999; 2012), argues that cognitive and social processes are building blocks for developing a coherent sense of self, resulting in self-concept clarity across various domains in life (e.g., [pro-]social, academic, and physical). Here, we show how this framework guides and can benefit from recent findings on (1) the prolonged and nonlinear structural brain development during childhood and adolescence, (2) insights from developmental neuroimaging studies using self-concept appraisal paradigms, (3) genetic and environmental influences on behavioral and neural correlates of self-concept development, and (4) youth's perspectives on self-concept development in the context of 21st century global challenges. We examine how neuroscience can inform theory by testing several compelling questions related to stability versus change of neural, behavioral, and self-report measures and we reflect on the meaning of variability and change/growth.

Who is at risk? Applying the biopsychosocial model to explain non-violent and violent delinquency in youth

Research has highlighted the relevance of biological measures in explaining antisocial behavior, but the inclusion of such measures in clinical practice is lagging behind. According to the integrative biopsychosocial model, biological measures should be studied together with psychological and social-environmental factors. In this data-driven study, we applied this comprehensive model to explain non-violent and violent delinquency of 876 at-risk youth (715 male, 9-27 years), by combining nine biological (autonomic-nervous-system; endocrinological), nine psychological, and seven social-environmental measures. Using latent-class-regression analysis we uncovered four distinct psychologically-driven biological clusters, which differed in non-violent and violent delinquency-risk, moderated by social-environmental variables: a biological-psychopathic traits; low problem; high problem; and biological-reactive group. Individual vulnerabilities to (non-)violent delinquency depended on social-environmental context that differed between clusters. These findings highlight the importance of biological and psychological factors, in the context of social-environmental factors, in explaining (non)-violent delinquency.

Growing Up Together in Society (GUTS): A team science effort to predict societal trajectories in adolescence and young adulthood

Our society faces a great diversity of opportunities for youth. The 10-year Growing Up Together in Society (GUTS) program has the long-term goal to understand which combination of measures best predict societal trajectories, such as school success, mental health, well-being, and developing a sense of belonging in society. Our leading hypothesis is that self-regulation is key to how adolescents successfully navigate the demands of contemporary society. We aim to test these questions using socio-economic, questionnaire (including experience sampling methods), behavioral, brain (fMRI, sMRI, EEG), hormonal, and genetic measures in four large cohorts including adolescents and young adults. Two cohorts are designed as test and replication cohorts to test the developmental trajectory of self-regulation, including adolescents of different socioeconomic status thereby bridging individual, family, and societal perspectives. The third cohort consists of an entire social network to examine how neural and self-regulatory development influences and is influenced by whom adolescents and young adults choose to interact with. The fourth cohort includes youth with early signs of antisocial and delinquent behavior to understand patterns of societal development in individuals at the extreme ends of self-regulation and societal participation, and examines pathways into and out of delinquency. We will complement the newly collected cohorts with data from existing large-scale population-based and case-control cohorts. The study is embedded in a transdisciplinary approach that engages stakeholders throughout the design stage, with a strong focus on citizen science and youth participation in study design, data collection, and interpretation of results, to ensure optimal translation to youth in society.

Influence of physical fitness components on personality factors and risk perception of children and adolescents: a cross-sectional study

OBJECTIVES

To examine the associations of cardiorespiratory fitness (VO2 max) and muscular strength with indicators related to the risk scale, such as perceived competence, sensation seeking, competitiveness, risk taking and risk perception in sports.

DESIGN

Cross-sectional study.

SETTING

High schools from the Region of Murcia (Spain).

PARTICIPANTS

Three-hundred-and-seventeen adolescents participated (mean age: 13.69±1.2 years old).

PRIMARY AND SECONDARY OUTCOME MEASURES

Body mass, body height, Course-Navette test, upper limb strength and psychoeducational factors that determine the propensity towards sports accidents in school children, the Sports Accident Propensity Scale were evaluated. It was performance t-test for independent samples, stepwise multiple linear regression models and a multiple mediation analysis.

RESULTS

The analysis showed significant differences with respect to sex in height, VO2 max, handgrip strength and in all factors of the questionnaire (p=0.02-<0.01). Adolescents who presented greater VO2 max, strength in the handgrip test and age showed a higher score in factors 1 and 3. Higher scores in factor 2 were associated with better VO2 max and strength in handgrip test. Youngers and better values of strength in the handgrip showed higher score in factors 4 and 5. The mediation analysis with two mediating variables (handgrip strength and VO2 max) showed a significant indirect effect. When handgrip strength and VO2 max were included in the equations, the association between sex and each factor ceased to be significant.

CONCLUSION

This study highlights the potential benefits of muscular strength (handgrip) and VO2 max in the perceived risk scale, and the variable of age on this.

TRIAL REGISTRATION NUMBER

Clinical trial: NCT05544370 (pre-results).

Neurobiological correlates of antisociality across adolescence and young adulthood: a multi-sample, multi-method study

BACKGROUND

Antisociality across adolescence and young adulthood puts individuals at high risk of developing a variety of problems. Prior research has linked antisociality to autonomic nervous system and endocrinological functioning. However, there is large heterogeneity in antisocial behaviors, and these neurobiological measures are rarely studied conjointly, limited to small specific studies with narrow age ranges, and yield mixed findings due to the type of behavior examined.

METHODS

We harmonized data from 1489 participants (9-27 years, 67% male), from six heterogeneous samples. In the resulting dataset, we tested relations between distinct dimensions of antisociality and heart rate, pre-ejection period (PEP), respiratory sinus arrhythmia, respiration rate, skin conductance levels, testosterone, basal cortisol, and the cortisol awakening response (CAR), and test the role of age throughout adolescence and young adulthood.

RESULTS

Three dimensions of antisociality were uncovered: 'callous-unemotional (CU)/manipulative traits', 'intentional aggression/conduct', and 'reactivity/impulsivity/irritability'. Shorter PEPs and higher testosterone were related to CU/manipulative traits, and a higher CAR is related to both CU/manipulative traits and intentional aggression/conduct. These effects were stable across age.

CONCLUSIONS

Across a heterogeneous sample and consistent across development, the CAR may be a valuable measure to link to CU/manipulative traits and intentional aggression, while sympathetic arousal and testosterone are additionally valuable to understand CU/manipulative traits. Together, these findings deepen our understanding of the fundamental mechanisms underlying different components of antisociality. Finally, we illustrate the potential of using current statistical techniques for combining multiple datasets to draw robust conclusions about biobehavioral associations.

A comprehensive review on the role of testosterone on the neurobehavioral systems implicated in the reinforcement sensitivity theory of personality

OBJECTIVES

The Reinforcement Sensitivity Theory (RST) is a neuropsychological theory of personality emphasizing approach and avoidance as the two core behavioral aspects. Approach is represented by the behavioral approach system (BAS). Avoidance is represented by the behavioral inhibition system (BIS) and the fight-flight-freeze system (FFFS). Although the influence of testosterone on human behavior has been demonstrated, few studies have investigated the relation between testosterone and the RST. The aim of this narrative review was to decipher the possible role of testosterone on the biological systems involved in the RST in humans.

METHODS

Google scholar, PubMed, PsycARTICLES, PsycINFO, Scopus and Cochrane library databases were interrogated using keywords such as testosterone, BIS, BAS, FFFS, personality, reinforcement sensitivity theory.

RESULTS

Seven original articles, published between 2009 and 2022, assessing the relation between testosterone and the systems implicated in the RST, were included. The results of these studies suggested the presence of a possible positive relation between testosterone and the BAS. However, the impact of testosterone on the BIS and/or FFFS seems to be less clear.

DISCUSSION

The consistency in the results supporting the presence of a positive relation between testosterone and the BAS might lead to the consideration of testosterone as a potential correlate in the clinical assessment of several psychopathologies. The inconsistency in the conclusions regarding the impact of testosterone on the BIS and/or the FFFS might be attributed to the different questionnaires used as measurement tools. Additional research remains needed.

Puberty and risky decision-making in male adolescents

Pubertal development is a potential trigger for increases in risk-taking behaviours during adolescence. Here, we sought to investigate the relationship between puberty and neural activation during risky decision-making in males using functional magnetic resonance imaging (fMRI). Forty-seven males aged 12.5-14.5 years completed an fMRI risk-taking task (BART) and reported their tendencies for risky decision-making using a self-report questionnaire. Puberty was assessed through self-reported pubertal status and salivary testosterone levels. Testosterone concentration, but not physical pubertal status, was positively correlated with self-reported risk-taking behaviour, while neither was correlated with BART performance. Across the whole sample, participants had greater activation of the bilateral nucleus accumbens and right caudate on trials when they made a successful risky decision compared to trials when they made a safe choice or when their risky decision was unsuccessful. There was a negative correlation between pubertal stage and brain activation during unsuccessful risky decision-making trials compared within unsuccessful control trials. Males at a lower stage of pubertal development showed increased activation in the left insula, right cingulate cortex, dorsomedial prefrontal cortex (dmPFC), right putamen and right orbitofrontal cortex (OFC) relative to more pubertally mature males during trials when they chose to take a risk and the balloon popped compared to when they watched the computer make an unsuccessful risky decision. Less pubertally mature males also showed greater activation in brain regions including the dmPFC, right temporal and frontal cortices, right OFC, right hippocampus and occipital cortex in unsuccessful risky trials compared to successful risky trials. These results suggest a puberty-related shift in neural activation within key brain regions when processing outcomes of risky decisions, which may reduce their sensitivity to negative feedback, and in turn contribute to increases in adolescent risk-taking behaviours.

Influence of ovarian hormones on value-based decision-making systems: Contribution to sexual dimorphisms in mental disorders

Women and men exhibit differences in behavior when making value-based decisions. Various hypotheses have been proposed to explain these findings, stressing differences in functional lateralization of the brain, functional activation, neurotransmitter involvement and more recently, sex hormones. While a significant interaction of neurotransmitter systems and sex hormones has been shown for both sexes, decision-making in women might be particularly affected by variations of ovarian hormones. In this review we have gathered information from animal and human studies on how ovarian hormones affect decision-making processes in females by interacting with neurotransmitter systems at functionally relevant brain locations and thus modify the computation of decision aspects. We also review previous findings on impaired decision-making in animals and clinical populations with substance use disorder and depression, emphasizing how little we know about the role of ovarian hormones in aberrant decision-making.

Are adolescents more optimal decision-makers in novel environments? Examining the benefits of heightened exploration in a patch foraging paradigm

Adolescence is a period of heightened exploration relative to adulthood and childhood. This predisposition has been linked with negative behaviours related to risk-taking, including dangerous driving, substance misuse and risky sexual practices. However, recent models have argued that adolescents' heightened exploration serves a functional purpose within the lifespan, allowing adolescents to develop experiential knowledge of their surroundings. Yet, there is limited evidence that heightened exploration in adolescence is associated with positive outcomes. To address this, the present pre-registered study utilised a foraging paradigm with a sample of adolescents aged 16-17 (N = 68) and of adults aged 21 and above (N = 69). Participants completed a patch foraging task, which required them to choose between exploiting a known resource which gradually yields fewer rewards, and exploring a novel, unknown resource with a fresh distribution of rewards. Findings demonstrated that adolescents explored more than adults, which - in the context of the current task-represented more optimal patch foraging behaviour. These findings indicate that adolescents' heightened exploration can be beneficial, as they were able to effectively navigate unknown environments and accrue rewards more successfully than adults. This provides evidence that heightened exploration in adolescence, relative to adulthood, can lead to positive outcomes and contributes to our understanding of the role increased novelty-seeking plays at this point in the lifespan.

Neural and behavioral signatures of social evaluation and adaptation in childhood and adolescence: The Leiden consortium on individual development (L-CID)

The transition period between early childhood and late adolescence is characterized by pronounced changes in social competence, or the capacity for flexible social adaptation. Here, we propose that two processes, self-control and prosociality, are crucial for social adaptation following social evaluation. We present a neurobehavioral model showing commonalities in neural responses to experiences of social acceptance and rejection, and multiple pathways for responding to social context. The Leiden Consortium on Individual Development (L-CID) provides a comprehensive approach towards understanding the longitudinal developmental pathways of, and social enrichment effects on, social competence, taking into account potential differential effects of such enrichment. Using Neurosynth based brain maps we point towards the medial prefrontal cortex as an important region integrating social cognition, self-referential processing and self-control for learning to respond flexibly to changing social contexts. Based on their role in social evaluation processing, we suggest to examine medial prefrontal cortex connections with lateral prefrontal cortex and the ventral striatum as potential neural differential susceptibility markers, in addition to previously established markers of differential susceptibility.

Neuropsychological development in adolescents: Longitudinal associations with white matter microstructure

Important neuropsychological changes during adolescence coincide with the maturation of white matter microstructure. Few studies have investigated the association between neuropsychological development and white matter maturation longitudinally. We aimed to characterize developmental trajectories of inhibition, planning, emotion recognition and risk-taking and examine whether white matter microstructural characteristics were associated with neuropsychological development above and beyond age. In an accelerated longitudinal cohort design, n = 112 healthy adolescents between ages 9 and 16 underwent cognitive assessment and diffusion MRI over three years. Fractional anisotropy (FA) and mean diffusivity (MD) were extracted for major white matter pathways using an automatic probabilistic reconstruction technique and mixed models were used for statistical analyses. Inhibition, planning and emotion recognition performance improved linearly across adolescence. Risk-taking developed in a quadratic fashion, with stable performance between 9 and 12 and an increase between ages 12 and 16. Including cingulum and superior longitudinal fasciculus FA slightly improved model fit for emotion recognition across age. We found no evidence that FA or MD were related to inhibition, planning or risk-taking across age. Our results challenge the additional value of white matter microstructure to explain neuropsychological development in healthy adolescents, but more longitudinal research with large datasets is needed to identify the potential role of white matter microstructure in cognitive development.

Social withdrawal and testosterone levels in early adolescent boys

Social withdrawal may lead to mental health problems and can have a large impact on a life course, particularly among boys. To support adolescents with social withdrawal, an integrative understanding of the biological bases would be helpful. Social dominance, a possible opposite of social withdrawal, is known to have positive associations with testosterone levels. A previous study suggested that social withdrawal has a negative relationship with sexual maturity among adolescent boys. However, the relationship between social withdrawal and testosterone in adolescence is unknown. This study aimed to examine whether social withdrawal was negatively associated with testosterone levels in early adolescent boys. Salivary samples were collected from 159 healthy early adolescent boys (mean age [standard deviation]: 11.5 [0.73]) selected from participants of the "population-neuroscience study of the Tokyo Teen Cohort" (pn-TTC). Social withdrawal and confounding factors, such as the secondary sexual characteristics and their age in months, were evaluated by self-administered questionnaires completed by the primary parents. The degree of social withdrawal was assessed with the Child Behaviour Checklist (CBCL). Levels of salivary testosterone, and cortisol as a control, were measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Logistic regression was conducted to examine the association between social withdrawal and testosterone levels. A higher risk of social withdrawal was associated with a lower salivary testosterone level after adjustment for age in months (odds ratio 0.55, 95 % confidence interval 0.33-0.94), and the association remained significant after adjusting for body mass index, the degree of anxiety/depression and pubertal stage. Thus, we found a negative relationship between social withdrawal and testosterone levels in early adolescent boys. These findings may help to clarify the biological foundations of and to develop support for social withdrawal.

Self and Others in Adolescence

Research has demonstrated that adolescence is an important time for self- and other-oriented development that underlies many skills vital for becoming a contributing member of society with healthy intergroup relations. It is often assumed that these two processes, thinking about self and thinking about others, are pitted against each other when adolescents engage in social decision making such as giving or sharing. Recent evidence from social neuroscience, however, does not support this notion of conflicting motives, suggesting instead that thinking about self and others relies on a common network of social-affective brain regions, with the medial prefrontal cortex playing a central role in the integration of perspectives related to self and others. Here, we argue that self- and other-oriented thinking are intertwined processes that rely on an overlapping neural network. Adolescents’ motivation to contribute to society can be fostered most when self- and other-oriented motives align.

Sex differences and brain development during puberty and adolescence

Sex differences in behavior, and whether these behavioral differences are related to sex differences in brain development, has been a longstanding topic of debate. Presumably, sex differences can provide critically important leads for explaining the etiology of various illnesses that show (i) large sex differences in prevalence and (ii) have an origin before or during adolescence. The general aim of this chapter is to provide an overview of scientific studies on sex differences in normative brain and behavioral development across puberty and adolescence, including the (sex) hormone-driven transition phase of puberty. Moreover, we describe the literature on brain and behavioral development in gender dysphoria, a severe and persistent incongruence between the self-identified gender and the assigned sex at birth. From the literature it becomes clear there is evidence for a specific link between pubertal maturation and developmental changes in arousal, motivation, and emotion. However, this link is rather similar between boys and girls. Moreover, although there is substantial evidence for sex differences in mean brain structure, these have not always been linked to sex differences in behavior, cognition, or psychopathology. Furthermore, there is little evidence for sex differences in brain development and thus, studies so far have been unable to explain sex differences in cognition. Suggestions for future research and methodologic considerations are provided.

Developmental Changes and Individual Differences in Trust and Reciprocity in Adolescence

A Trust Game was used to examine trust and reciprocity development in 12-18-year-old-adolescents (N = 496), as findings have been conflicting and transitions in adolescence remain elusive. Furthermore, this study tested the roles of gender, risk, and individual differences in empathy, impulsivity, and antisocial tendencies in trust and reciprocity. Results indicate stability in trust and a decrease in reciprocity across adolescence, but also show that trust and reciprocity choices were influenced by risk, and that empathy mediated the age-related decrease in reciprocity. Males trusted more than females, but there were no gender differences in reciprocity. These findings highlight the importance of considering individual differences and adolescents' sensitivities to varying contexts in explaining trust and reciprocity development in adolescence.

Behavioral and Neural Pathways Supporting the Development of Prosocial and Risk-Taking Behavior Across Adolescence

This study tested the pathways supporting adolescent development of prosocial and rebellious behavior. Self‐report and structural brain development data were obtained in a three‐wave, longitudinal neuroimaging study (8–29 years, N = 210 at Wave 3). First, prosocial and rebellious behavior assessed at Wave 3 were positively correlated. Perspective taking and intention to comfort uniquely predicted prosocial behavior, whereas fun seeking (current levels and longitudinal changes) predicted both prosocial and rebellious behaviors. These changes were accompanied by developmental declines in nucleus accumbens and medial prefrontal cortex (MPFC) volumes, but only faster decline of MPFC (faster maturity) related to less rebellious behavior. These findings point toward a possible differential susceptibility marker, fun seeking, as a predictor of both prosocial and rebellious developmental outcomes.

A three-wave longitudinal study of subcortical-cortical resting-state connectivity in adolescence: Testing age- and puberty-related changes

Adolescence is the transitional period between childhood and adulthood, characterized by substantial changes in reward‐driven behavior. Although reward‐driven behavior is supported by subcortical‐medial prefrontal cortex (PFC) connectivity, the development of these circuits is not well understood. Particularly, while puberty has been hypothesized to accelerate organization and activation of functional neural circuits, the relationship between age, sex, pubertal change, and functional connectivity has hardly been studied. Here, we present an analysis of resting‐state functional connectivity between subcortical structures and the medial PFC, in 661 scans of 273 participants between 8 and 29 years, using a three‐wave longitudinal design. Generalized additive mixed model procedures were used to assess the effects of age, sex, and self‐reported pubertal status on connectivity between subcortical structures (nucleus accumbens, caudate, putamen, hippocampus, and amygdala) and cortical medial structures (dorsal anterior cingulate, ventral anterior cingulate, subcallosal cortex, frontal medial cortex). We observed an age‐related strengthening of subcortico‐subcortical and cortico‐cortical connectivity. Subcortical–cortical connectivity, such as, between the nucleus accumbens—frontal medial cortex, and the caudate—dorsal anterior cingulate cortex, however, weakened across age. Model‐based comparisons revealed that for specific connections pubertal development described developmental change better than chronological age. This was particularly the case for changes in subcortical–cortical connectivity and distinctively for boys and girls. Together, these findings indicate changes in functional network strengthening with pubertal development. These changes in functional connectivity may maximize the neural efficiency of interregional communication and set the stage for further inquiry of biological factors driving adolescent functional connectivity changes.

Longitudinal structural brain development and externalizing behavior in adolescence

BACKGROUND

Cross-sectional studies report relations between externalizing behavior and structural abnormalities in cortical thickness of prefrontal regions and volume reductions in subcortical regions. To understand how these associations emerge and develop, longitudinal designs are pivotal.

METHOD

In the current longitudinal study, a community sample of children, adolescents and young adults (N = 271) underwent magnetic resonance imaging (MRI) in three biennial waves (680 scans). At each wave, aspects of externalizing behavior were assessed with parent-reported aggression and rule-breaking scores (Child Behavior Checklist), and self-reported aggression scores (Buss-Perry Aggression Questionnaire). Regions of interest (ROIs) were selected based on prior research: dorsolateral prefrontal (dlPFC), orbitofrontal (OFC), anterior cingulate cortex (ACC), insula, and parahippocampal cortex, as well as subcortical regions. Linear mixed models were used to assess the longitudinal relation between externalizing behavior and structural brain development. Structural covariance analyses were employed to identify whether longitudinal relations between ROIs (maturational coupling) were associated with externalizing behavior.

RESULTS

Linear mixed model analyses showed a negative relation between parent-reported aggression and right hippocampal volume. Moreover, this longitudinal relation was driven by change in hippocampal volume and not initial volume of hippocampus at time point 1. Exploratory analyses showed that stronger maturational coupling between prefrontal regions, the limbic system, and striatum was associated with both low and high externalizing behavior.

CONCLUSIONS

Together, these findings reinforce the hypothesis that altered structural brain development coincides with development of more externalizing behavior. These findings may guide future research on normative and deviant development of externalizing behavior.

Novel insights from the Yellow Light Game: Safe and risky decisions differentially impact adolescent outcome-related brain function

Changes across the span of adolescence in the adolescent reward system are thought to increase the tendency to take risks. While developmental differences in decision and outcome-related reward processes have been studied extensively, existing paradigms have largely neglected to measure how different types of decisions modulate reward-related outcome processes. We modified an existing decision-making paradigm (the Stoplight Task; Chein et al., 2011) to create a flexible laboratory measure of decision-making and outcome processing, including the ability to assess modulatory effects of safe versus risky decisions on reward-related outcome processes: the Yellow Light Game (YLG). We administered the YLG in the MRI scanner to 81 adolescents, ages 11-17 years, recruited from the community. Results showed that nucleus accumbens activation was enhanced for (1) risky > safe decisions, (2) positive > negative outcomes, and (3) outcomes following safe decisions compared to outcomes following risky decisions, regardless of whether these outcomes were positive or negative. Outcomes following risky decisions (compared to outcomes following safe decisions) were associated with enhanced activity in cortical midline structures. Furthermore, while there were no developmental differences in risk-taking behavior, more pubertally mature adolescents showed enhanced nucleus accumbens activation during positive > negative outcomes. These findings suggest that outcome processing is modulated by the types of decisions made by adolescents and highlight the importance of investigating processes involved in safe as well as risky decisions to better understand the adolescent tendency to take risks.