This article reviews neuroimaging, neurocognitive, and preclinical findings on the effects of cannabis on the adolescent brain. Marijuana is the second most widely used intoxicant in adolescence, and ...teens who engage in heavy marijuana use often show disadvantages in neurocognitive performance, macrostructural and microstructural brain development, and alterations in brain functioning. It remains unclear whether such disadvantages reflect pre-existing differences that lead to increased substances use and further changes in brain architecture and behavioral outcomes. Future work should focus on prospective investigations to help disentangle dose-dependent effects from pre-existing effects, and to better understand the interactive relationships with other commonly abused substances (e.g., alcohol) to better understand the role of regular cannabis use on neurodevelopmental trajectories.
This study sought to assess the performance of the Fitbit Charge HR, a consumer-level multi-sensor activity tracker, to measure physical activity and sleep in children.
59 healthy boys and girls aged ...9-11 years old wore a Fitbit Charge HR, and accuracy of physical activity measures were evaluated relative to research-grade measures taken during a combination of 14 standardized laboratory- and field-based assessments of sitting, stationary cycling, treadmill walking or jogging, stair walking, outdoor walking, and agility drills. Accuracy of sleep measures were evaluated relative to polysomnography (PSG) in 26 boys and girls during an at-home unattended PSG overnight recording. The primary analyses included assessment of the agreement (biases) between measures using the Bland-Altman method, and epoch-by-epoch (EBE) analyses on a minute-by-minute basis.
Fitbit Charge HR underestimated steps (~11.8 steps per minute), heart rate (~3.58 bpm), and metabolic equivalents (~0.55 METs per minute) and overestimated energy expenditure (~0.34 kcal per minute) relative to research-grade measures (p< 0.05). The device showed an overall accuracy of 84.8% for classifying moderate and vigorous physical activity (MVPA) and sedentary and light physical activity (SLPA) (sensitivity MVPA: 85.4%; specificity SLPA: 83.1%). Mean estimates of bias for measuring total sleep time, wake after sleep onset, and heart rate during sleep were 14 min, 9 min, and 1.06 bpm, respectively, with 95.8% sensitivity in classifying sleep and 56.3% specificity in classifying wake epochs.
Fitbit Charge HR had adequate sensitivity in classifying moderate and vigorous intensity physical activity and sleep, but had limitations in detecting wake, and was more accurate in detecting heart rate during sleep than during exercise, in healthy children. Further research is needed to understand potential challenges and limitations of these consumer devices.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
This review examines neuroimaging and neurocognitive findings on alcohol-related toxicity in adolescents. Teens who meet criteria for alcohol use disorders, as well as those who engage in ...subdiagnostic binge drinking behaviors, often show poorer neurocognitive performance, alterations in gray and white matter brain structure, and discrepant functional brain activation patterns when compared to nonusing and demographically matched controls. Abnormalities are also observed in teens with a family history of alcoholism, and such differences in neuromaturation may leave youths at increased risk for the development of an alcohol use disorder or increased substance use severity. More prospective investigations are needed, and future work should focus on disentangling preexisting differences from dose-dependent effects of alcohol on neurodevelopment. Intervention strategies that utilize neuroimaging findings (e.g., identified weaknesses in particular neural substrates and behavioral correlates) may be helpful in both prevention and intervention campaigns for teens both pre- and postinitiation of alcohol use.
Dynamic changes in neurochemistry, fiber architecture, and tissue composition occur in the adolescent brain. The course of these maturational processes is being charted with greater specificity, ...owing to advances in neuroimaging and indicate grey matter volume reductions and protracted development of white matter in regions known to support complex cognition and behavior. Though fronto-subcortical circuitry development is notable during adolescence, asynchronous maturation of prefrontal and limbic systems may render youth more vulnerable to risky behaviors such as substance use. Indeed, binge-pattern alcohol consumption and comorbid marijuana use are common among adolescents, and are associated with neural consequences. This review summarizes the unique characteristics of adolescent brain development, particularly aspects that predispose individuals to reward seeking and risky choices during this phase of life, and discusses the influence of substance use on neuromaturation. Together, findings in this arena underscore the importance of refined research and programming efforts in adolescent health and interventional needs.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The Adolescent Brain and Cognitive Development (ABCD) Study incorporates a comprehensive range of measures assessing predictors and outcomes related to both mental and physical health across ...childhood and adolescence. The workgroup developed a battery that would assess a comprehensive range of domains that address study aims while minimizing participant and family burden. We review the major considerations that went into deciding what constructs to cover in the demographics, physical health and mental health domains, as well as the process of selecting measures, piloting and refining the originally proposed battery. We present a description of the baseline battery, as well as the six-month interim assessments and the one-year follow-up assessments. This battery includes assessments from the perspectives of both the parent and the target youth, as well as teacher reports. This battery will provide a foundational baseline assessment of the youth’s current function so as to permit characterization of stability and change in key domains over time. The findings from this battery will also be utilized to identify both resilience markers that predict healthy development and risk factors for later adverse outcomes in physical health, mental health, and substance use and abuse.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Background Very few studies have been performed to understand the underlying neural substrates of adolescent major depressive disorder (MDD). Studies in depressed adults have demonstrated that the ...subgenual anterior cingulate cortex (sgACC) plays a pivotal role in depression and have revealed aberrant patterns of resting-state functional connectivity (RSFC). Here, we examine the RSFC of the sgACC in medication-naïve first-episode adolescents with MDD. Methods Twenty-three adolescents with MDD and 36 well-matched control subjects underwent functional magnetic resonance imaging to assess the RSFC of the sgACC. Results We observed elevated connectivity between the sgACC and the insula and between the sgACC and the amygdala in the MDD group compared with the control subjects. Decreased connectivity between the sgACC and the precuneus was also found in the MDD group relative to the control subjects. Within the MDD group, higher levels of depression significantly correlated with decreased connectivity between the sgACC and left precuneus. Increased rumination was significantly associated with reduced connectivity between sgACC and the middle and inferior frontal gyri in the MDD group. Conclusions Our study is the first to examine sgACC connectivity in medication-naïve first-episode adolescents with MDD compared with well-matched control participants. Our results suggest aberrant functional connectivity among the brain networks responsible for salience attribution, executive control, and the resting-state in the MDD group compared with the control participants. Our findings raise the possibility that therapeutic interventions that can restore the functional connectivity among these networks to that typical of healthy adolescents might be a fruitful avenue for future research.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Objective:Data on the neurodevelopmental and associated behavioral effects of light to moderate in utero alcohol exposure are limited. This retrospective investigation tested for associations between ...reported maternal prenatal alcohol use and psychological, behavioral, and neurodevelopmental outcomes in substance-naive youths.Methods:Participants were 9,719 youths (ages 9.0 to 10.9 years) from the Adolescent Brain Cognitive Development Study. Based on parental reports, 2,518 (25.9%) had been exposed to alcohol in utero. Generalized additive mixed models and multilevel cross-sectional and longitudinal mediation models were used to test whether prenatal alcohol exposure was associated with psychological, behavioral, and cognitive outcomes, and whether differences in brain structure and resting-state functional connectivity partially explained these associations at baseline and 1-year follow-up, after controlling for possible confounding factors.Results:Prenatal alcohol exposure of any severity was associated with greater psychopathology, attention deficits, and impulsiveness, with some effects showing a dose-dependent response. Children with prenatal alcohol exposure, compared with those without, displayed greater cerebral and regional volume and greater regional surface area. Resting-state functional connectivity was largely unaltered in children with in utero exposure. Some of the psychological and behavioral outcomes at baseline and at the 1-year follow-up were partially explained by differences in brain structure among youths who had been exposed to alcohol in utero.Conclusions:Any alcohol use during pregnancy is associated with subtle yet significant psychological and behavioral effects in children. Women should continue to be advised to abstain from alcohol consumption from conception throughout pregnancy.
Objective: To investigate the strength and reproducibility of the teratogenic impact of prenatal tobacco exposure (PTE) on child physical health and neurodevelopmental outcomes, in the context of ...intersecting sociodemographic and other prenatal correlates, and test if early postnatal health mediates PTE associations with childhood outcomes. Method: Among 9-10-year-olds (N = 8,803) in the Adolescent Brain Cognitive Development Study, linear mixed-effect models tested PTE associations with birth and childhood outcomes of physical health, cognitive performance, and brain structure, controlling for confounding sociodemographic and prenatal health correlates. Mediation analysis tested the extent to which health at birth explained the associations between PTE and childhood outcomes. Results: PTE was reported by 12% of mothers (8% n = 738 pre-knowledge of pregnancy only, and 4% n = 361 pre- and post-knowledge of pregnancy). PTE was highest for children with a risk for passive smoke exposure. Overall, children with any PTE had shorter breastfeeding durations than those without PTE, and PTE following knowledge of pregnancy was associated with being small for gestational age having lower birth weight, and obesity and lower cortical volume and surface area in childhood. Among children from high-parent education households, any PTE was related to lower cognitive performance, which was partially mediated by duration of breastfeeding. Conclusions: PTE was linked to poorer health indicators at birth and neurodevelopmental outcomes at age 9-10 years in a large community cohort, independent of sociodemographic factors. Efficacious interventions for smoking-cessation during pregnancy are still needed and should incorporate support for breastfeeding to promote healthier development.
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CEKLJ, FFLJ, NUK, ODKLJ, PEFLJ, UPUK
Background
The influence of repeated substance use during adolescent neurodevelopment remains unclear as there have been few prospective investigations. The aims of this study were to identify ...longitudinal changes in fiber tract integrity associated with alcohol‐ and marijuana‐use severity over the course of 1.5 years.
Methods
Adolescents with extensive marijuana‐ and alcohol‐use histories by mid‐adolescence (n = 41) and youth with consistently minimal if any substance use (n = 51) were followed over 18 months. Teens received diffusion tensor imaging and detailed substance‐use assessments with toxicology screening at baseline and 18‐month follow‐ups (i.e., 182 scans in all), as well as interim substance‐use interviews each 6 months.
Results
At an 18‐month follow‐up, substance users showed poorer white matter integrity in 7 tracts: (i) right superior longitudinal fasciculus, (ii) left superior longitudinal fasciculus, (iii) right posterior thalamic radiations, (iv) right prefrontal thalamic fibers, (v) right superior temporal gyrus white matter, (vi) right inferior longitudinal fasciculus, and (vii) left posterior corona radiata (ps < 0.01). More alcohol use during the interscan interval predicted higher mean diffusivity (i.e., worsened integrity) in right (p < 0.05) and left (p = 0.06) superior longitudinal fasciculi, above and beyond baseline values in these bundles. Marijuana use during the interscan interval did not predict change over time. More externalizing behaviors at Time 1 predicted lower fractional anisotropy and higher radial diffusivity (i.e., poorer integrity) of the right prefrontal thalamic fibers (p < 0.025).
Conclusions
Findings add to previous cross‐sectional studies reporting white matter disadvantages in youth with substance‐use histories. In particular, alcohol use during adolescent neurodevelopment may be linked to reductions in white matter quality in association fiber tracts with frontal connections. In contrast, youth who engage in a variety of risk‐taking behaviors may have unique neurodevelopmental trajectories characterized by truncated development in fronto‐thalamic tracts, which could have functional and clinical consequences in young adulthood.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Late adolescence (ie, 16-20 years of age) is a period characterized by escalation of drinking and alcohol use problems for many and by the onset of an alcohol use disorder for some. This heightened ...period of vulnerability is a joint consequence of the continuity of risk from earlier developmental stages and the unique neurologic, cognitive, and social changes that occur in late adolescence. We review the normative neurologic, cognitive, and social changes that typically occur in late adolescence, and we discuss the evidence for the impact of these transitions on individual drinking trajectories. We also describe evidence linking alcohol abuse in late adolescence with neurologic damage and social impairments, and we discuss whether these are the bases for the association of adolescent drinking with increased risks of mental health, substance abuse, and social problems in adulthood. Finally, we discuss both the challenges and successes in the treatment and prevention of adolescent drinking problems.
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