Adolescent brain development and underage drinking in the United States: identifying risks of alcohol use in college populations

Binge alcohol consumption in emerging adults: anterior cingulate cortical "thinness" is associated with alcohol use patterns

BACKGROUND

The brain undergoes dynamic and requisite changes into the early 20s that are associated with improved cognitive efficiency, particularly in prefrontal regions that are still undergoing neuromaturation. As alcohol consumption is typically initiated and progresses to binge drinking (BD) during this time, the objective of the present study was to investigate the impact of binge alcohol consumption on frontal lobe cortical thickness in emerging adults.

METHODS

Twenty-three binge drinking (11 females, mean age 22.0 ± 1.2) and 31 light drinking (15 females, mean age 21.5 ± 1.6) emerging adults underwent high-resolution magnetic resonance imaging at 3 Tesla. Cortical surface reconstruction and thickness estimation were performed using FreeSurfer for 3 a priori brain regions of interest: bilateral anterior cingulate cortex (ACC), posterior cingulate cortex (PCC), and parieto-occipital sulcus (POS). Cortical thickness measurements were then compared between binge drinker (BD) and light drinker (LD) groups.

RESULTS

Cortical thickness was significantly lower in BD than LD in the right middle ACC (mid-ACC; p ≤ 0.05) and in the left dorsal PCC (dPCC; p ≤ 0.01). No significant differences in cortical thickness were observed in the POS. Cortical thickness in the mid-ACC correlated negatively with higher quantity and frequency of drinks consumed (p < 0.01) and positively with the number of days elapsed since most recent use (p < 0.05). Furthermore, less cortical thickness in the mid-ACC in the BD group alone correlated with reported patterns of high quantity and frequency of alcohol consumption (p ≤ 0.05).

CONCLUSIONS

Findings suggest that past and recent patterns of intermittent heavy alcohol consumption are associated with less frontal cortical thickness (i.e., "thinness") of the right mid-ACC and left dPCC in emerging adults, but not the POS. While cortical thinness could have predated binge drinking, this pattern of maladaptive consumption may have acute neurotoxic effects that interfere with the finalization of neuromaturational processes in the vulnerable frontal cortex, resulting in increased microarchitectural pruning.

Providing alcohol to underage youth: the view from young adulthood

BACKGROUND

Many underage drinkers obtain alcohol from legal-age family, friends, and acquaintances. This study aimed to understand the attitudes and behaviors of young adults related to providing alcohol to underage drinkers.

METHODS

Participants were 755 current or recent college students of legal drinking age (ages 22 to 26) who were approached by a minor to provide alcohol at least once since turning 21. Interviewers assessed frequency of providing alcohol, relationship to the recipients, and general attitudes about providing alcohol to minors. Separate questions asked about younger (under 18) and older (18 to 20) minors. Correlates and predictors of provision and frequency of provision were examined via logistic regression and Poisson regression, focusing on demographics, sensation-seeking, behavioral dysregulation, age at first drink, parental history of alcohol problems, fraternity/sorority involvement, attitudes about provision, violations, peer drinking norms, and alcohol use disorder (AUD) risk during and post-college.

RESULTS

Most participants (84.6%) provided alcohol to minors at least once. Provision to older minors was more prevalent (82.8%) than to younger minors (20.7%); it was also more frequent. Few (2.4%) were ever caught providing alcohol. Recipients were more commonly friends or family members rather than acquaintances or strangers. Legal concerns about providing alcohol (82.5 and 53.7% for younger and older minors, respectively) were more prevalent than health concerns (55.7 and 9.5%). Legal concerns consistently predicted lower likelihood of provision, independent of demographics. Health concerns and lower post-college AUD risk scores also independently predicted lower likelihood of provision, but only to older minors. Fraternity/sorority involvement and higher peer drinking norms were associated with higher provision frequency, whereas legal concerns and college violations were associated with lower provision frequency.

CONCLUSIONS

Young adults who have recently turned 21 could represent an important target for prevention strategies to reduce underage drinking on college campuses. More research is needed to understand the motivations of young adults who provide alcohol to underage drinkers.

GABAergic contributions to alcohol responsivity during adolescence: insights from preclinical and clinical studies

There is a considerable body of literature demonstrating that adolescence is a unique age period, which includes rapid and dramatic maturation of behavioral, cognitive, hormonal and neurobiological systems. Most notably, adolescence is also a period of unique responsiveness to alcohol effects, with both hyposensitivity and hypersensitivity observed to the various effects of alcohol. Multiple neurotransmitter systems are undergoing fine-tuning during this critical period of brain development, including those that contribute to the rewarding effects of drugs of abuse. The role of developmental maturation of the γ-amino-butyric acid (GABA) system, however, has received less attention in contributing to age-specific alcohol sensitivities. This review integrates GABA findings from human magnetic resonance spectroscopy studies as they may translate to understanding adolescent-specific responsiveness to alcohol effects. Better understanding of the vulnerability of the GABA system both during adolescent development, and in psychiatric conditions that include alcohol dependence, could point to a putative mechanism, boosting brain GABA, that may have increased effectiveness for treating alcohol use disorders.

Perspectives on the neuroscience of alcohol from the National Institute on Alcohol Abuse and Alcoholism

Mounting evidence over the last 40 years clearly indicates that alcoholism (alcohol dependence) is a disorder of the brain. The National Institute on Alcohol Abuse and Alcoholism (NIAAA) has taken significant steps to advance research into the neuroscience of alcohol. The Division of Neuroscience and Behavior (DNB) was formed within NIAAA in 2002 to oversee, fund, and direct all research areas that examine the effects of alcohol on the brain, the genetic underpinnings of alcohol dependence, the neuroadaptations resulting from excessive alcohol consumption, advanced behavioral models of the various stages of the addiction cycle, and preclinical medications development. This research portfolio has produced important discoveries in the etiology, treatment, and prevention of alcohol abuse and dependence. Several of these salient discoveries are highlighted and future areas of neuroscience research on alcohol are presented.

fMRI response during figural memory task performance in college drinkers

RATIONALE

Eighteen- to twenty-five-year-olds show the highest rates of alcohol use disorders (AUD) and heavy drinking, which may have critical neurocognitive implications. Regions subserving memory may be particularly susceptible to alcohol-related impairments.

OBJECTIVE

We used blood oxygen level-dependent (BOLD) functional magnetic resonance imaging (fMRI) to examine the neural correlates of visual encoding and recognition among heavy-drinking college students. We predicted that heavy drinkers would show worse memory performance, increased frontal/parietal activation, and decreased hippocampal response during encoding.

METHODS

Participants were 23 heavy drinkers and 33 demographically matched light drinkers, aged 18-20, characterized using quantity/frequency of drinking and AUD diagnosis. Participants performed a figural encoding and recognition task during fMRI. BOLD response during encoding was modeled based on whether each stimulus was subsequently recognized or forgotten (i.e., correct vs. incorrect encoding).

RESULTS

There were no group differences in behavioral performance. Compared to light drinkers, heavy drinkers showed (1) greater BOLD response during correct encoding in the right hippocampus/medial temporal, right dorsolateral prefrontal, left inferior frontal, and bilateral posterior parietal cortices; (2) less left inferior frontal activation and greater bilateral precuneus deactivation during incorrect encoding; and (3) less bilateral insula response during correct recognition (clusters >10,233 μl, p < 0.05 whole brain).

CONCLUSIONS

This is the first investigation of the neural substrates of figural memory among heavy-drinking older adolescents. Heavy drinkers demonstrated compensatory hyperactivation of memory-related areas during correct encoding, greater deactivation of default mode regions during incorrect encoding, and reduced recognition-related response. Results could suggest use of different encoding and recognition strategies among heavy drinkers.

A triadic neurocognitive approach to addiction for clinical interventions

According to the triadic neurocognitive model of addiction to drugs (e.g., cocaine) and non-drugs (e.g., gambling), weakened "willpower" associated with these behaviors is the product of an abnormal functioning in one or more of three key neural and cognitive systems: (1) an amygdala-striatum dependent system mediating automatic, habitual, and salient behaviors; (2) a prefrontal cortex dependent system important for self-regulation and forecasting the future consequences of a behavior; and (3) an insula dependent system for the reception of interoceptive signals and their translation into feeling states (such as urge and craving), which in turn plays a strong influential role in decision-making and impulse control processes related to uncertainty, risk, and reward. The described three-systems account for poor decision-making (i.e., prioritizing short-term consequences of a decisional option) and stimulus-driven actions, thus leading to a more elevated risk for relapse. Finally, this article elaborates on the need for "personalized" clinical model-based interventions targeting interactions between implicit processes, interoceptive signaling, and supervisory function aimed at helping individuals become less governed by immediate situations and automatic pre-potent responses, and more influenced by systems involved in the pursuit of future valued goals.

Why adolescents are at risk of misusing alcohol and gambling

AIMS

The aim of the study was to explore the reasons for alcohol misuse and other risk-taking behaviours in adolescence.

METHODS

Narrative review.

RESULTS

Vulnerable adolescents make suboptimal addictive-related choices in the period of initiation of alcohol use and gambling, which is also a period of cognitive and brain development, and in health behaviours. Hyperactive response to rewards as well as possibly hypoactive responses to punishments combined with weaknesses in the abilities to regulate strong impulses results in greater risk of alcohol and gambling misuse.

CONCLUSION

Abnormal patterns of alcohol consumption (e.g. binge drinking) could dramatically reinforce this disequilibrium by enhancing salience for alcohol and associated information and compromising self-regulatory processes. There are some preventive and therapeutic cognitive training strategies that can strengthen willpower in adolescents.

Frontal lobe γ-aminobutyric acid levels during adolescence: associations with impulsivity and response inhibition

BACKGROUND

The brain undergoes major remodeling during adolescence, resulting in improved cognitive control and decision-making and reduced impulsivity, components of behavior mediated in part by the maturing frontal lobe. γ-Aminobutyric acid (GABA), the main inhibitory neurotransmitter system, also matures during adolescence, with frontal lobe GABA receptors reaching adult levels late in adolescence. Thus, the objective of this study was to characterize in vivo developmental differences in brain GABA levels.

METHODS

Proton magnetic resonance spectroscopy was used at 4 T to acquire metabolite data from the anterior cingulate cortex (ACC) and the parieto-occipital cortex (POC) in adolescents (n=30) and emerging adults (n = 20).

RESULTS

ACC GABA/creatine (Cr) levels were significantly lower in adolescents relative to emerging adults, whereas no age differences were observed in the POC. Lower ACC GABA/Cr levels were significantly associated with greater impulsivity and worse response inhibition, with relationships being most pronounced for ACC GABA/Cr and No-Go response inhibition in adolescent males.

CONCLUSIONS

These data provide the first human developmental in vivo evidence confirming frontal lobe GABA maturation, which was linked to impulsiveness and cognitive control. These findings suggest that reduced GABA may be an important neurobiological mechanism in the immature adolescent brain, contributing to the reduced yet rapidly developing ability to inhibit risky behaviors and to make suboptimal decisions, which could compromise adolescent health and safety.

Executive functioning among young people in relation to alcohol use

PURPOSE OF REVIEW

This article reviews recent findings regarding neurobehavioral factors which may be associated with risk for alcohol misuse, as well as those which may occur as a result of alcohol misuse during adolescence and emerging adulthood.

RECENT FINDINGS

Current research extends previous findings by engaging multiple assessment methods and integrating behavioral and imaging technologies. These efforts reinforce previous findings regarding alcohol-related changes in macrostructure while demonstrating alterations in brain connectivity previously underappreciated. Longitudinal work now being reported suggests problem use during adolescence may be associated with persistent neurobehavioral aberrations.

SUMMARY

For many years, little attention was directed to the neurobehavioral consequences of alcohol use across adolescence and emerging adulthood or to the neurobehavioral factors which might predispose youth to alcohol misuse. Recent work provides critical insights regarding the underpinnings of the deficits in executive function often observed in those at risk for alcohol dependence and those who develop alcohol use disorders. These studies suggest that, even when behavioral deficits are not evident, changes in brain connectivity and microstructure may be observed. Programmatic, longitudinal research must be conducted to determine the relevance of these alterations to use trajectories and long-term adaptation.