A practical guide for researchers and reviewers using the ABCD Study and other large longitudinal datasets

As the largest longitudinal study of adolescent brain development and behavior to date, the Adolescent Brain Cognitive Development (ABCD) Study® has provided immense opportunities for researchers across disciplines since its first data release in 2018. The size and scope of the study also present a number of hurdles, which range from becoming familiar with the study design and data structure to employing rigorous and reproducible analyses. The current paper is intended as a guide for researchers and reviewers working with ABCD data, highlighting the features of the data (and the strengths and limitations therein) as well as relevant analytical and methodological considerations. Additionally, we explore justice, equity, diversity, and inclusion efforts as they pertain to the ABCD Study and other large-scale datasets. In doing so, we hope to increase both accessibility of the ABCD Study and transparency within the field of developmental cognitive neuroscience.

Pubertal sex hormones control transcriptional trajectories in the medial preoptic area

Pubertal maturation aids development of emotion, cognition, and reproduction. We investigated transcriptional dynamics in the medial preoptic area (MPOA), a hypothalamic center for reproductive behaviors, in male and female mice at single-cell resolution (scRNAseq) during puberty. Defined subsets of neurons expressing Slc32a1 and Esr1 (Vgat+ Esr1+) were the most transcriptionally dynamic compared to other cell types throughout puberty. These cell type specific transcriptional progressions towards adulthood were bidirectionally controlled by the levels of circulating testosterone and estradiol. Selective deletion of Esr1 in Slc32a1-expressing cells in the MPOA prior to puberty arrested transcriptional progression and revealed a sexually dimorphic gene-regulatory network governed by Esr1. Deletion of Esr1 in Vgat+ cells prevented the development of mating behavior in both sexes. These analyses reveal both sexually common and dimorphic transcriptional progressions during puberty as well as their regulatory mechanisms, which have important implications towards understanding adaptative and maladaptive processes governing adolescent brain development.

The Developing Brain in the Digital Era: A Scoping Review of Structural and Functional Correlates of Screen Time in Adolescence

The widespread diffusion of screen-based devices in adolescence has fueled a debate about the beneficial and detrimental effects on adolescents’ well-being and development. With the aim of summarizing the existing literature on the associations between screen time (including Internet-related addictions) and adolescent brain development, the present scoping review summarized evidence from 16 task-unrelated and task-related neuroimaging studies, published between 2010 and 2020. Results highlight three important key messages: (i) a frequent and longer duration of screen-based media consumption (including Internet-related addictive behaviors) is related to a less efficient cognitive control system in adolescence, including areas of the Default Mode Network and the Central Executive Network; (ii) online activities act as strong rewards to the brain and repeated screen time augments the tendency to seek short-term gratifications; and (iii) neuroscientific research on the correlates between screen time and adolescent brain development is still at the beginning and in urgent need for further evidence, especially on the underlying causality mechanisms. Methodological, theoretical, and conceptual implications are discussed.

Adolescent Binge Drinking is Associated with Accelerated Decline of Gray Matter Volume

The age- and time-dependent effects of binge-drinking on adolescent brain development have not been well characterized even though binge drinking is a health crisis among adolescents. The impact of binge drinking on gray matter volume development was examined using longitudinal data from the National Consortium on Alcohol and NeuroDevelopment in Adolescence (NCANDA). Non-binge drinkers (n=177) were matched to binge drinkers (n=164) on potential confounders. Number of binge drinking episodes in the past year was linked to decreased volumes for total gray matter, frontal, parietal, temporal, and occipital lobes (ps<.001). Interactions of binge drinking episodes and age demonstrated stronger effects in younger subjects for total gray matter, frontal, temporal, and occipital lobes (ps<.001). Subsequent models included binge drinking coded in multiple ways. Models sensitive to number of episodes and temporal proximity to outcomes provided the best fits. Declines in gray matter volume association with binge drinking are potentially related to changes in cognition frequently reported among binge drinking adolescents. Results underscore the potential importance of delaying initiation of binge drinking and provide evidence for a dose-response relationship of binge drinking to gray matter decline. Temporally proximal binge drinking was associated more strongly with gray matter decline, suggesting the potential for recovery.

Exploration of Epigenetic State Hyperdopaminergia (Surfeit) and Genetic Trait Hypodopaminergia (Deficit) During Adolescent Brain Development

Background: Understanding the risk for all addictive drug and non-drug behaviors, especially, in the unmyelinated Prefrontal Cortex (PFC) of adolescents, is important and complex. Many animal and human studies show the epigenetic impact on the developing brain in adolescents, compared to adults. Some reveal an underlying hyperdopaminergia that seems to set our youth up for risky behaviors by inducing high quanta pre-synaptic dopamine release at reward site neurons. In addition, altered reward gene expression in adolescents caused epigenetically by social defeat, like bullying, can continue into adulthood. In contrast, there is also evidence that epigenetic events can elicit adolescent hypodopaminergia. This complexity suggests that neuroscience cannot make a definitive claim that all adolescents carry a hyperdopaminergia trait. Objective: The primary issue involves the question of whether there exists a mixed hypo or hyper –dopaminergia in this population. Method: Genetic Addiction Risk Score (GARS®) testing of 24 Caucasians, ages 12-19 derived from families with RDS. Results: We have found that adolescents from this cohort, derived from RDS parents, displays a high risk for any addictive behavior (a hypodopaminergia), especially, drug-seeking (95%) and alcohol-seeking (64 %). Conclusion: The adolescents in our study, although more work is required, show a hypodopaminergic trait, derived from a family with Reward Deficiency Syndrome (RDS). Certainly in future studies we will analyze GARS in non-RDS Caucasians between the ages of 12-19. The suggestion is first to identify risk alleles with the GARS test and, then, use well-researched precision, pro-dopamine neutraceutical regulation. This “two-hit” approach might prevent tragic fatalities among adolescents, in the face of the American opioid/psychostimulant, epidemic.

Considerations in the Neuroscience of Adolescent Brain Development: What Clinicians Can Use

Neuroscience findings suggest brain immaturity and the proliferation of neurons in the frontal cortex at puberty may be significant factors affecting adolescent behaviors. The author considers these findings essential to bolster the analyst’s position to not act, in light of the impulses treating such cases can arouse. Clinical examples illustrate.