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Adolescence is a unique period in neurodevelopment. Alcohol and marijuana use are common. Recent research has indicated that adolescent substance users show abnormalities on measures of brain functioning, which is linked to changes in neurocognition over time. Abnormalities have been seen in brain structure volume, white matter quality, and activation to cognitive tasks, even in youth with as little as 1–2 years of heavy drinking and consumption levels of 20 drinks per month, especially if >4–5 drinks are consumed on a single occasion. Heavy marijuana users show some subtle anomalies too, but generally not the same degree of divergence from demographically similar non-using adolescents. This article reviews the extant literature on neurocognition, brain structure, and brain function in adolescent substance users with an emphasis on the most commonly used substances, and in the context of ongoing neuromaturational processes. Methodological and treatment implications are provided.

This study prospectively examines the influence of alcohol on neuropsychological functioning in a sample of boys and girls who were characterized prior to initiating drinking (N=76, ages 12-14). Adolescents who transitioned into heavy (n= 25; 11 female, 14 male) or moderate (n=11; 2 female, 9 male) drinking were compared to demographically-matched controls who remained non-users throughout the approximately 3-year follow-up period (n=40; 16 female, 24 male). For girls, more drinking days in the past year predicted a greater reduction in performance on visuospatial tasks from baseline to follow-up, above and beyond performance on equivalent measures at baseline (R 2 Δ = 10%, p <. 05), particularly on tests of visuospatial memory (R 2 Δ = 8%, p < .05). For boys, a tendency was seen for more hangover symptoms in the year before follow-up testing to predict a relative worsening of sustained attention (R 2 Δ = 7%, p < .05). These preliminary longitudinal findings suggest that initiating moderately heavy alcohol use and incurring hangover during adolescence may adversely influence neurocognitive functioning. Neurocognitive deficits linked to heavy drinking during this critical developmental period may lead to direct and indirect changes in neuromaturational course, with effects that would extend into adulthood.

Background Problems inhibiting non-adaptive behaviors have been linked to an increased risk for substance use and other risk taking behaviors in adolescence. This study examines the hypothesis that abnormalities in neural activation during inhibition in early adolescence may predict subsequent substance involvement. Methods Thirty eight adolescents from local area middle schools, ages 12–14, with very limited histories of substance use, underwent functional magnetic resonance imaging (fMRI) as they performed a go/no-go task of response inhibition and response selection. Adolescents and their parents were then followed annually with interviews covering substance use and other behaviors. Based on follow-up data, youth were classified as transitioning to heavy use of alcohol (TU; n=21), or as healthy controls (CON; n=17). Results At baseline, prior to the onset of use, youth who later transitioned into heavy use of alcohol showed significantly less activation than those who went on to remain non to minimal users throughout adolescence. Activation reductions in TU at baseline were seen on no-go trials in 12 brain regions, including right inferior frontal gyrus, left dorsal and medial frontal areas, bilateral motor cortex, cingulate gyrus, left putamen, bilateral middle temporal gyri, and bilateral inferior parietal lobules (corrected p < .01, each cluster ≥ 32 contiguous voxels). Conclusions These results support the hypothesis that less neural activity during response inhibition demands predicts future involvement with problem behaviors such as alcohol and other substance use.

Rationale Adolescent binge drinking is concerning, as important neurodevelopments occur during this stage. Previous research suggests that binge drinking may disrupt typical brain development, and females may be particularly vulnerable. Objectives We used magnetic resonance imaging (MRI) to examine cortical thickness in adolescent females and males with and without histories of binge drinking. Methods Participants (N=59) were 16–19-year-old adolescents recruited from local schools. Recent binge drinkers (n=29, 48% female) were matched to non-drinkers (n=30, 50% female) on age, gender, pubertal development, and familial alcoholism. Participants completed a neuropsychological battery and MRI session. Cortical surfaces were reconstructed with FreeSurfer. Results Binge × gender interactions (p<.05) were seen for cortical thickness in four left frontal regions: frontal pole, pars orbitalis, medial orbital frontal, and rostral anterior cingulate. For all interactions, female bingers had thicker cortices than female controls, while male bingers had thinner cortices than male controls. Thicker left frontal cortices corresponded with poorer visuospatial, inhibition, and attention performances for female bingers (r=−0.69 to 0.50, p<0.05) and worse attention for male bingers (r=−0.69, p=0.005). Conclusions Adolescent females with recent binge drinking showed ~8% thicker cortices in left frontal regions than demographically similar female non-drinkers, which was linked to worse visuospatial, inhibition, and attention performances. In contrast, adolescent binge-drinking males showed ~7% thinner cortices in these areas than non-drinking males. These cross-sectional data suggest either different gray matter risk factors for males as for females toward developing heavy drinking, or differential adverse sequelae.

Background Binge drinking is prevalent during adolescence, and its effect on neurocognitive development is of concern. In adult and adolescent populations, heavy substance use has been associated with decrements in cognitive functioning, particularly on tasks of spatial working memory (SWM). Characterizing the gender-specific influences of heavy episodic drinking on SWM may help elucidate the early functional consequences of drinking on adolescent brain functioning. Methods 40 binge drinkers (13 females, 27 males) and 55 controls (24 females, 31 males) ages 16 to 19, completed neuropsychological testing, substance use interviews, and a spatial working memory task (SWM) during functional magnetic resonance imaging (fMRI). Results Significant binge drinking status x gender interactions were found (p<.05) in 8 brain regions spanning bilateral frontal, anterior cingulate, temporal, and cerebellar cortices. In all regions, female binge drinkers showed less SWM activation than female controls, while male bingers exhibited greater SWM response than male controls. For female binge drinkers, less activation was associated with poorer sustained attention and working memory performances (ps<.025). For male binge drinkers, greater activation was linked to better spatial performance (p<.025). Conclusion Binge drinking during adolescence is associated with gender-specific differences in frontal, temporal, and cerebellar brain activation during a SWM task, which in turn relate to cognitive performance. Activation correlates with neuropsychological performance, strengthening the argument that BOLD activation is both affected by alcohol use and is an important indicator of behavioral functioning. Females may be more vulnerable to the neurotoxic effects of heavy alcohol use during adolescence, while males may be more resilient to the deleterious effects of binge drinking. Future longitudinal research will examine the significance of SWM brain activation as an early neurocognitive marker of alcohol impact to the brain on future behaviors such as driving safety, academic performance, and neuropsychological performance.

Background Heavy alcohol use during adolescence may alter the trajectory of normal brain development. Whether developmental trajectories of regional cortical volume and white matter structures are differentially affected in heavy drinkers relative to non-drinking controls has not been studied over extended periods or with sample sizes adequate to address potential sex differences. Methods This longitudinal study examined gray and white matter volume trajectories in 134 adolescents (75 who transitioned into heavy drinking and 59 who remained light to non-drinkers over roughly 3.5 years). Each underwent magnetic resonance imaging (MRI) on a 3T system two to six times (390 total scans) between ages 12 to 24 and was followed up to 8 years. Volumes of neocortex, allocortex, and white matter structures were measured using atlas-based parcellation with longitudinal registration. Linear mixed-effects models described differences in trajectories of drinkers and controls over age; secondary analyses considered the contribution of other drug use to identified alcohol use effects. Results Heavy-drinking adolescents showed accelerated gray matter reduction in cortical lateral frontal and temporal volumes and attenuated white matter growth of the corpus callosum and pons relative to controls. These results were essentially the same when marijuana and other drug use were examined. Male and female drinkers showed similar patterns of development trajectory abnormalities. Discussion Longitudinal analysis enabled detection of accelerated typical volume decline in frontal and temporal cortical volumes and attenuated growth in principal white matter structures in adolescents who started to drink heavily. These results provide a call for caution regarding heavy alcohol use during adolescence, whether heavy alcohol drinking is the cause or one of many factors in a constellation of causes of these alterations in brain development.

Background: Electronic cigarettes (e-cigarettes) were first introduced in the U.S. market in 2006, with the more recent evolution of "pod-mod" e-cigarettes such as JUUL introduced in 2015. Although marketed as a smoking cessation tool, e-cigarettes are rarely used for this purpose in youth. This review aims to synthesize the literature regarding e-cigarette use among youth, and provides a resource for clinicians, educators, and families that helps answer commonly asked questions about e-cigarettes. Methods: PubMed, Scopus, and PsycINFO search was performed using search terms "Electronic Nicotine Delivery Systems," "e cigarettes," "e-cigarettes," "electronic cigarettes," "vaping," "JUUL," "e-cigs," and "vape pens." Search results were filtered to only include those related to adolescents and young adults. Results: E-cigarette use among youth is common, with rates of use increasing from 1.5% in 2011 to 20.8% in 2018. Pod mod devices such as JUUL have gained favor among youth for their sleek design, user-friendly function, desirable flavors, and ability to be used discreetly in places where smoking is forbidden. Adolescents are often uninformed about the constituents of ecigarettes, and little is known about the long-term effects of e-cigarettes. Studies have suggested a "gateway" effect for combustible cigarettes and cannabis use. Conclusions: E-cigarette use is becoming increasingly common among youth, leading to a myriad of questions and concerns from providers, educators, and family members. More research is needed to determine the ultimate public health impact of e-cigarette use. The authors provide a summary table of frequently asked questions in order to help clarify these common concerns.