Effects of family history of alcohol use disorders on spatial working memory BOLD response in adolescents

Neural activations during cognitive and affective theory of mind processing in healthy adults with a family history of alcohol use disorder

BACKGROUND

Social cognition impairments are a common feature of alcohol use disorders (AUD). However, it remains unclear whether these impairments are solely the consequence of chronic alcohol consumption or whether they could be a marker of vulnerability.

METHODS

The present study implemented a family history approach to address this question for a key process of social cognition: theory of mind (ToM). Thirty healthy adults with a family history of AUD (FH+) and 30 healthy adults with a negative family history of AUD (FH-), matched for age, sex, and education level, underwent an fMRI cartoon-vignette paradigm assessing cognitive and affective ToM. Participants also completed questionnaires evaluating anxiety, depressive symptoms, childhood trauma, and alexithymia.

RESULTS

Results indicated that FH+ individuals differed from FH- individuals on affective but not cognitive ToM processing, at both the behavioral and neural levels. At the behavioral level, the FH+ group had lower response accuracy for affective ToM compared with the FH- group. At the neural level, the FH+ group had higher brain activations in the left insula and inferior frontal cortex during affective ToM processing. These activations remained significant when controlling for depressive symptoms, anxiety, and childhood trauma.

CONCLUSIONS

These findings highlight difficulties during affective ToM processing among first-degree relatives of AUD patients, supporting the idea that some of the impairments exhibited by these patients may already be present before the onset of AUD and may be considered a marker of vulnerability.

Alcohol and the Adolescent Brain: What We've Learned and Where the Data Are Taking Us

This article is part of a Festschrift commemorating the 50th anniversary of the National Institute on Alcohol Abuse and Alcoholism (NIAAA). Established in 1970, first as part of the National Institute of Mental Health and later as an independent institute of the National Institutes of Health, NIAAA today is the world's largest funding agency for alcohol research. In addition to its own intramural research program, NIAAA supports the entire spectrum of innovative basic, translational, and clinical research to advance the diagnosis, prevention, and treatment of alcohol use disorder and alcohol-related problems. To celebrate the anniversary, NIAAA hosted a 2-day symposium, "Alcohol Across the Lifespan: 50 Years of Evidence-Based Diagnosis, Prevention, and Treatment Research," devoted to key topics within the field of alcohol research. This article is based on Dr. Tapert's presentation at the event. NIAAA Director George F. Koob, Ph.D., serves as editor of the Festschrift.

Maternal drinking behaviour and co-exposure from smoking during and after pregnancy in relation to the neurocognitive function of school-children in the rural Western Cape

BACKGROUND

Maternal substance use and its long-term effect on the neurocognitive functions of children is a global public health issue. Despite an increase in substance use in rural areas of low to middle-income countries, research is limited in these populations.

OBJECTIVE

We have therefore explored the effect of maternal drinking and smoking behaviors on the neurocognitive functioning of rural school children.

METHOD

A cross-sectional analysis on the determinants of current, past and gestational maternal alcohol use and gestational smoking on child neurocognitive functions was conducted on school-children (N = 482), embedded within the child health agricultural cohort (CapSA) study across seven schools in rural Western Cape, South Africa. Standardised neurocognitive assessment tools included the Cambridge Automated Neuropsychological Battery (CANTAB) and the KIDSCREEN-10 to measure health-related quality of life via a child questionnaire. Maternal smoking and drinking behaviour were captured using a parent/guardian questionnaire.

RESULTS

Of the 482 parents/guardians who completed the survey, 29 % reported current drinking 27 % reported past drinking and 10 % reported maternal gestational drinking, while 31 % reported gestational smoking. Significant associations were observed between past and current maternal drinking and child's reduced rapid visual processing accuracy in attention [β:-0.03; 95 % confidence interval (CI): -0.05;-0.004] and between maternal drinking during pregnancy and reduced child's spatial working memory (β: -0.59; CI: -1.02; -0.15). Heavy (>5 cigarettes per day) gestational smoking was associated with lowered child's learning in memory (β:-1.69; 95 % CI: -3.05; -0.33) and lower health-related quality of life (β: -3.41; CI: -6.64; -0.17). The odds of a child repeating a grade were 1.69 (CI: 2.81-1.02) for those exposed to maternal gestational smoking and 1.68 (CI: 3.31-0.85) for those exposed to maternal gestational drinking compared to those who were not exposed.

CONCLUSION

The consistent negative associations across all four maternal substance use proxies, six neurocognitive health outcomes and one health symptom is suggestive of adverse health effects, warranting longitudinal follow-up. Health policies to eliminate gestational substance use are recommended.

The effect of alcohol use on neuroimaging correlates of cognitive and emotional processing in human adolescence

OBJECTIVE

This article provides an overview of the scientific literature pertaining to the effects of alcohol on neural correlates of cognitive and emotional functioning, including reward processing and cue-reactivity, in adolescence and young adulthood.

METHOD

Peer-reviewed, original research articles that included a neuroimaging assessment of alcohol effects on subsequent cognitive or emotional processing in adolescent or young adult samples were searched (through November 2018) and summarized in the review.

RESULTS

Cross-sectional studies provided early evidence of alcohol-related differences in neural processing across a number of cognitive domains. Longitudinal studies have identified neural abnormalities that predate drinking within most domains of cognitive functioning, while a few neural alterations have been observed within the domains of visual working memory, inhibitory control, reward processing, and cue-reactivity that appear to be related to the neurotoxic effect of alcohol use during adolescence. In contrast, neural correlates of emotion functioning appear to be relatively stable to the effects of alcohol.

CONCLUSIONS

Larger prospective studies are greatly needed to disentangle premorbid factors from neural consequences associated with drinking, and to detect subsets of youth who may be particularly vulnerable to alcohol's effects on cognitive and emotional functioning. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Cognitive and behavioural dispositions in offspring at high risk for alcoholism

OBJECTIVES

Offspring with family history of alcoholism are considered to be at high risk for alcoholism. The present study sought to expand our understanding of cognitive and behavioural dispositions associated with executive control and self-regulation in alcohol naïve offspring with and without family history of alcoholism.

METHODS

Sample comprised of alcohol naive offspring in two groups: (i) at high risk (n = 34) and (ii) at low risk for alcoholism (n = 34). Both groups were matched on age (+/-1 year), education (+/-1 year) and gender. Measures used were: Mini-International Neuropsychiatric Interview, Family Interview for Genetic Studies, Socio-demographic Data Sheet, Annett's Handedness Questionnaire, Barratt's Impulsiveness Scale-version 11, Digit Span Test, Spatial Span Test, Tower of London, Wisconsin Card Sorting Test, Iowa Gambling Task (IGT) and Game of Dice Task (GDT).

RESULTS

Results showed that alcohol naive offspring at high risk for alcoholism reported significantly high impulsivity and demonstrated significant differences on executive functions and decision making tasks. Correlation analysis revealed that high impulsivity was significantly associated with poor performance on explicit decision making task (GDT) and executive function task (WCST). There was no significant correlation between two decision making tasks (IGT and GDT) in both groups and performance on IGT was not significantly associated with impulsivity and executive functions.

CONCLUSIONS

The present study indicates cognitive and behavioural dispositions in alcohol naive offspring at high risk for alcoholism and support the sub-optimal balance between reflective and impulsive system responsible for addiction. Furthermore, present study supports separability between two different types of decision making tasks.

Neural and psychological characteristics of college students with alcoholic parents differ depending on current alcohol use

A significant proportion of college students are adult children of an alcoholic parent (ACoA), which can confer greater risk of depression, poor self-esteem, alcohol and drug problems, and greater levels of college attrition. However, some ACoA are resilient to these negative outcomes. The goal of this study was to better understand the psychobiological factors that distinguish resilient and vulnerable college-aged ACoAs. To do so, scholastic performance and psychological health were measured in ACoA college students not engaged in hazardous alcohol use (resilient) and those currently engaged in hazardous alcohol use (vulnerable). Neural activity (as measured by functional magnetic resonance imaging) in response to performing working memory and emotion-based tasks were assessed. Furthermore, the frequency of polymorphisms in candidate genes associated with substance use, risk taking and stress reactivity were compared between the two ACoA groups. College ACoAs currently engaged in hazardous alcohol use reported more anxiety, depression and posttraumatic stress symptoms, and increased risky nicotine and marijuana use as compared to ACoAs resistant to problem alcohol use. ACoA college students with current problem alcohol showed greater activity of the middle frontal gyrus and reduced activation of the posterior cingulate in response to visual working memory and emotional processing tasks, which may relate to increased anxiety and problem alcohol and drug behaviors. Furthermore, polymorphisms of cholinergic receptor and the serotonin transporter genes also appear to contribute a role in problem alcohol use in ACoAs. Overall, findings point to several important psychobiological variables that distinguish ACoAs based on their current alcohol use that may be used in the future for early intervention.

Cortical Thickness in Adolescents with a Family History of Alcohol Use Disorder

BACKGROUND

Individuals with a family history (FH+) of alcohol use disorder (AUD) have a higher risk for developing an AUD than those with no family history (FH-) of AUD. In addition, FH+ individuals tend to perform worse on neuropsychological measures and show heightened impulsivity, which may be due to underlying differences in brain structure such as cortical thickness. The primary aim of this study was to investigate differences in cortical thickness in FH+ compared to FH- adolescents. Secondary aims were to (i) investigate differences in executive functioning and impulsivity, and (ii) examine associations between brain structure and behavior.

METHODS

Brain scans of 95 FH- and 93 FH+ subjects aged 13 to 18 were obtained using magnetic resonance imaging. FH+ subjects were required to have at least 1 biological parent with a history of an AUD. FH+ and FH- individuals had limited or no past alcohol use, thereby minimizing potential effects of alcohol. Subjects were evaluated on impulsivity and executive functioning tasks. Thicknesses of cortical lobes and subregions were analyzed using FreeSurfer. Regions showing group differences were examined for group-by-age interactions and correlations with neuropsychological and personality measures.

RESULTS

FH+ adolescents had thinner cortices in frontal and parietal lobes, notably in the medial orbitofrontal, lateral orbitofrontal, and superior parietal cortices. The difference in cortical thickness between family history groups was strongest among the youngest subjects. FH+ subjects were also more impulsive and had poorer performance on a spatial memory task.

CONCLUSIONS

These findings demonstrate frontal and parietal structural differences in FH+ adolescents that might underlie cognitive and behavioral characteristics associated with AUD risk.

Association of Drinking Problems and Duration of Alcohol Use to Inhibitory Control in Nondependent Young Adult Social Drinkers

BACKGROUND

Deficits in inhibitory control have been widely implicated in alcohol misuse. However, the literature does not readily distinguish the effects of drinking problems and chronic alcohol use. Here, we examined how years of drinking and the Alcohol Use Disorders Identification Test (AUDIT) score each influences the cerebral responses to inhibitory control in nondependent drinkers.

METHODS

Fifty-seven adult drinkers and 57 age- and gender-matched nondrinkers participated in one 40-minute functional magnetic resonance imaging scan of the stop signal task. Data were preprocessed and modeled using SPM8. In a regression model, we contrasted stop and go success trials for individuals and examined activities of response inhibition each in link with the AUDIT score and years of alcohol use in group analyses. We specified the effects of duration of use by contrasting regional activations of drinkers and age-related changes in nondrinkers. In mediation analyses, we investigated how regional activities mediate the relationship between drinking problems and response inhibition.

RESULTS

Higher AUDIT score but not years of drinking was positively correlated with prolonged stop signal reaction time (SSRT) and diminished responses in the cerebellum, thalamus, frontal and parietal regions, independent of years of alcohol use. Further, activity of the thalamus, anterior cingulate cortex, and presupplementary motor area significantly mediates the association, bidirectionally, between the AUDIT score and SSRT. The duration of alcohol use was associated with decreased activation in the right inferior frontal gyrus extending to superior temporal gyrus, which was not observed for age-related changes in nondrinkers.

CONCLUSIONS

The results distinguished the association of drinking problems and years of alcohol use to inhibitory control in young adult nondependent drinkers. These new findings extend the imaging literature of alcohol misuse and may have implications for treatment to prevent the escalation from social to dependent drinking. More research is needed to confirm age-independent neural correlates of years of alcohol use.

Neurobiological phenotypes associated with a family history of alcoholism

BACKGROUND

Individuals with a family history of alcoholism are at much greater risk for developing an alcohol use disorder (AUD) than youth or adults without such history. A large body of research suggests that there are premorbid differences in brain structure and function in family history positive (FHP) individuals relative to their family history negative (FHN) peers.

METHODS

This review summarizes the existing literature on neurobiological phenotypes present in FHP youth and adults by describing findings across neurophysiological and neuroimaging studies.

RESULTS

Neuroimaging studies have shown FHP individuals differ from their FHN peers in amygdalar, hippocampal, basal ganglia, and cerebellar volume. Both increased and decreased white matter integrity has been reported in FHP individuals compared with FHN controls. Functional magnetic resonance imaging studies have found altered inhibitory control and working memory-related brain response in FHP youth and adults, suggesting neural markers of executive functioning may be related to increased vulnerability for developing AUDs in this population. Additionally, brain activity differences in regions involved in bottom-up reward and emotional processing, such as the nucleus accumbens and amygdala, have been shown in FHP individuals relative to their FHN peers.

CONCLUSIONS

It is critical to understand premorbid neural characteristics that could be associated with cognitive, reward-related, or emotional risk factors that increase risk for AUDs in FHP individuals. This information may lead to the development of neurobiologically informed prevention and intervention studies focused on reducing the incidence of AUDs in high-risk youth and adults.

Striatal activity and reduced white matter increase frontal activity in youths with family histories of alcohol and other substance-use disorders performing a go/no-go task

INTRODUCTION

Youths with a family history of alcohol and other drug use disorders (FH+) are at greater risk of developing substance-use disorders relative to those with no such family histories (FH-). We previously reported that FH+ youths have elevated activity in the supplementary motor area (SMA) and dorsal striatum while performing go/no-go tasks and have reduced frontal white matter integrity. A better understanding of relationships between these variables would provide insight into how frontostriatal circuitry is altered in FH+ youths, which may be an important contributor to their elevated risk.

METHODS

In this study, we used structural equation modeling (SEM) to test interactions between activity in the SMA and dorsal striatum in 72 FH+ and 32 FH- youths during go/no-go task performance and to determine whether increased activity in these regions in FH+ youths can be at least partially explained by reduced frontal white matter integrity, as indexed by anterior corona radiata fractional anisotropy and N-acetylaspartate.

RESULTS

Increased dorsal striatum activity explained most (∽75%) of the elevated SMA activity in FH+ youths, and the combined contributions of increased dorsal striatal activity, and decreased white matter integrity fully explained the elevated SMA activity.

CONCLUSIONS

These results suggest the elevated frontal cortical activity in FH+ youths is driven both by their increased striatal activity via downstream projections and reduced white matter integrity in frontal cortical projections, the latter likely increasing frontal cortical activity due to increased energy demands required for action potential propagation. As part of our ongoing longitudinal studies we will examine how these frontostriatal alterations relate to risk for developing substance-use disorders.

Endophenotypes for Alcohol Use Disorder: An Update on the Field

The endophenotype concept was first proposed as a strategy to use (purportedly) genetically simpler phenotypes in gene identification studies for psychiatric disorders, and is distinct from the closely related concept of intermediate phenotypes. In the area of alcohol use disorder (AUD) research, two candidate endophenotypes have produced replicable genetic associations: level of response to alcohol and neurophysiology markers (e.g., event-related oscillations and event-related potentials). Additional candidate endophenotypes from the cognitive, sensory, and neuroimaging literatures show promise, although more evidence is needed to fully evaluate their potential utility. Translational approaches to AUD endophenotypes have helped characterize the underlying neurobiology and genetics of AUD endophenotypes and identified relevant pharmacological interventions. Future research that capitalizes on the polygenic nature of endophenotypes and emphasizes endophenotypes that may change across development will enhance the usefulness of this concept to understand the genetically-influenced pathways toward AUD.

Amygdala Volume in Offspring from Multiplex for Alcohol Dependence Families: The Moderating Influence of Childhood Environment and 5-HTTLPR Variation

BACKGROUND

The increased susceptibility for developing alcohol dependence seen in offspring from families with alcohol dependence may be related to structural and functional differences in brain circuits that influence emotional processing. Early childhood environment, genetic variation in the serotonin transporter-linked polymorphic region (5-HTTLPR) of the SLCA4 gene and allelic variation in the Brain Derived Neurotrophic Factor (BDNF) gene have each been reported to be related to volumetric differences in the temporal lobe especially the amygdala.

METHODS

Magnetic resonance imaging was used to obtain amygdala volumes for 129 adolescent/young adult individuals who were either High-Risk (HR) offspring from families with multiple cases of alcohol dependence (N=71) or Low-Risk (LR) controls (N=58). Childhood family environment was measured prospectively using age-appropriate versions of the Family Environment Scale during a longitudinal follow-up study. The subjects were genotyped for Brain-Derived Neurotrophic Factor (BDNF) Val66Met and the serotonin transporter polymorphism (5-HTTLPR). Two family environment scale scores (Cohesion and Conflict), genotypic variation, and their interaction were tested for their association with amygdala volumes. Personal and prenatal exposure to alcohol and drugs were considered in statistical analyses in order to more accurately determine the effects of familial risk group differences.

RESULTS

Amygdala volume was reduced in offspring from families with multiple alcohol dependent members in comparison to offspring from control families. High-Risk offspring who were carriers of the S variant of the 5-HTTLPR polymorphism had reduced amygdala volume in comparison to those with an LL genotype. Larger amygdala volume was associated with greater family cohesion but only in Low-Risk control offspring.

CONCLUSIONS

Familial risk for alcohol dependence is an important predictor of amygdala volume even when removing cases with significant personal exposure and covarying for prenatal exposure effects. The present study provides new evidence that amygdala volume is modified by 5-HTTLPR variation in High-Risk families.

Increased forebrain activations in youths with family histories of alcohol and other substance use disorders performing a Go/NoGo task

BACKGROUND

Youths with a family history of alcohol and other drug use disorders (FH+) are at a greater risk of developing substance use disorders than their peers with no such family histories (FH-), and this increased risk may be related to impaired maturation of forebrain circuitry. FH+ individuals have shown altered forebrain activity at rest and while performing cognitive tasks. However, it is not fully understood how forebrain activity is altered in FH+ individuals, and ultimately how these alterations may contribute to substance use disorder risk.

METHODS

In this study, we tested 72 FH+ and 32 FH- youths performing a go/no-go task and examined activations in blocks with only go trials (Go Only), blocks with 50% go and 50% no-go trials (Go/NoGo), and a contrast of those 2 blocks.

RESULTS

FH+ youths had significantly greater cerebral activations in both the Go and Go/NoGo blocks than FH- youths in regions including the posterior cingulate/precuneus, bilateral middle/superior temporal gyrus, and medial superior frontal gyrus with no significant group differences in the subtraction between Go Only and Go/NoGo blocks. Additionally, FH+ youths had moderately slower reaction times on go trials in the Go Only blocks.

CONCLUSIONS

Our findings suggest that global activation increase in FH+ youths are modulated by FH density and are not specific to the inhibitory components of the task. This pattern of increased activations in FH+ youths may be at least partially due to impaired forebrain white matter development leading to greater activations/less efficient neural communication during task performance.

White matter integrity in alcohol-naive youth with a family history of alcohol use disorders

BACKGROUND

Understanding pre-existing neural vulnerabilities found in youth who are family history positive (FHP) for alcohol use disorders could help inform preventative interventions created to delay initiation age and escalation of heavy drinking. The goal of this study was to compare indices of white matter integrity using diffusion tensor imaging (DTI) between FHP and family history negative (FHN) youth using a sample of 94 alcohol-naive adolescents and to examine if differences were associated with global and domain-specific cognitive functioning.

METHOD

Participants were 48 FHP and 46 FHN demographically matched, healthy, substance-naive 12- to 14-year-olds (54% female) recruited from local middle schools. Participants completed a neuropsychological test battery and magnetic resonance imaging session, including DTI.

RESULTS

FHP youth had higher fractional anisotropy and axial diffusivity, and lower radial and mean diffusivity, than FHN youth in 19 clusters spanning projection, association and interhemispheric white matter tracts. Findings were replicated after controlling for age, gender, socio-economic status, grade and pubertal development. Groups did not differ significantly on global or domain-specific neuropsychological test scores.

CONCLUSIONS

FHP teens showed higher white matter integrity, but similar cognitive functioning, to FHN youth. More mature neural features could be related to more precocious behaviors, such as substance use initiation, in FHP youth. Future research exploring white matter maturation before and after substance use initiation will help elucidate the neurodevelopmental trajectories in youth at risk for substance use disorders, to inform preventive efforts and better understand the sequelae of adolescent alcohol and drug use.

Atypical parietal lobe activity to subliminal faces in youth with a family history of alcoholism

BACKGROUND

Adults with alcohol use disorders (AUDs) show different behavioral and neurological functioning during emotional processing tasks from healthy controls. Adults with a family history (FHP) of AUD also show different activation in limbic brain areas, such as the amygdala. However, it is unclear if this pattern exists during adolescence before any episodes of heavy alcohol use.

OBJECTIVES

We hypothesized that the amygdalar response to subliminally-presented fearful faces would be reduced in FHP adolescents compared to peers who were family history negative (FHN) for AUD.

METHOD

An adapted Masked Faces paradigm was used to examine blood oxygen level-dependent response to subliminal fearful vs. neutral faces in 14 FHP (6 females, 8 males) and 15 FHN (6 females, 9 males) youth, ages 11-15 years. Both FHP and FHN youth had no history of heavy alcohol consumption.

RESULTS

A significant difference was seen between groups in the left superior parietal lobule FHN youth showed deactivation to fearful and neutral masked faces compared to baseline, whereas FHP youth showed deactivation only to fearful masked faces. No significant differences in amygdalar activation were seen between groups.

CONCLUSION

The left superior parietal lobule is part of the fronto-parietal network, which has been implicated in attentional control. Lack of reduced neural activity to neutral faces among FHP youth may represent differences in suppressing attention networks to less salient emotional stimuli, or perhaps, a higher threshold of saliency for emotional stimuli among at-risk youth.

Family history of alcohol use disorders and neuromaturation: a functional connectivity study with adolescents

BACKGROUND

A positive family history (FHP) of alcohol use disorders (AUD) is linked to increased risk for personal AUD, but the mechanisms behind this risk are unclear. Previous research suggests that a subtle neurodevelopmental lag in FHP adolescents may contribute to risk for future AUD.

METHODS

Functional magnetic resonance imaging (fMRI) response to a spatial working memory (SWM) task was examined for markers of neuromaturational delay in 85 youth with and without FHP. It was hypothesized that FHP adolescents (n = 24, ages 12-14 years), as compared to matched FHN youth (n = 26, ages 12-14 years), would show less similarity to brain connectivity observed in older adolescents (n = 35, ages 16-20 years) and that statistical comparison of SWM functional connectivity models would differentiate FHN and FHP youth. Structural equation modeling tested the fit of brain response connectivity between FH groups and against the older-adolescent model.

RESULTS

Patterns of connectivity were more similar between older adolescent and FHN than FHP adolescents; FHP youth demonstrated higher association between right posterior and left frontal brain regions than FHN and older adolescent youth. Comparison of FH groups indicated a significant difference on the pathway from the right superior parietal lobule to the left middle frontal gyrus.

CONCLUSIONS

These findings provide additional support for the notion of a neuromaturational lag in FHP youth. Protracted neuromaturation may be a mechanism by which FH increases risk for alcohol dependence, and this less mature neural connectivity pattern may provide a novel endophenotype for identifying youth at risk for drinking problems.

Anomalous temporoparietal activity in individuals with a family history of alcoholism: studies from the Oklahoma Family Health Patterns Project

BACKGROUND

Individuals with a family history of alcoholism (FH+) are at enhanced risk of developing alcohol or other substance use disorders relative to those with no family history (FH-). Alcoholics and FH+ subjects have greater interference scores on the Stroop color-word task, suggesting these impairments may be a component of the cognitive phenotype of at-risk individuals.

METHODS

In this study, we examined whole-brain activations in 24 FH+ and 28 FH- young adults performing the counting Stroop task, a variant of the Stroop task adapted for neuroimaging studies.

RESULTS

Across all subjects, incongruent versus congruent comparisons showed activations in regions including parietal lobe areas, frontal eye fields, premotor areas, the anterior cingulate cortex, dorsolateral prefrontal cortex, and bilateral insula, indicating typical regions of activation involved in conflict resolution tasks. Compared with FH- participants, FH+ participants had greater activations in the left superior parietal lobule and precuneus (BA 7 and 19), inferior parietal lobule (BA 40), and middle temporal gyrus (BA 39 and 19), indicating a predominance of greater left hemisphere activity among FH+ in temporoparietal regions. There were no regions showing greater activations in the FH- group compared with the FH+ group.

CONCLUSIONS

These results are consistent with less efficient cognitive functioning potentially due to poorer communication over long pathways connecting temporoparietal regions to prefrontal brain regions that participate in a distributed network involved in cognitive processing and working memory necessary for conflict resolution.

Considering Cannabis: The Effects of Regular Cannabis Use on Neurocognition in Adolescents and Young Adults

Thirty-six percent of high school seniors have used cannabis in the past year, and an alarming 6.5% smoked cannabis daily, up from 2.4% in 1993 (Johnston et al., 2013). Adolescents and emerging adults are undergoing significant neurodevelopment and animal studies suggest they may be particularly vulnerable to negative drug effects. In this review, we will provide a detailed overview of studies outlining the effects of regular (at least weekly) cannabis use on neurocognition, including studies outlining cognitive, structural and functional findings. We will also explore the public health impact of this research.

Increased neural activity during high working memory load predicts low relapse risk in alcohol dependence

Working memory (WM) impairments are often observed in alcohol-dependent individuals, especially in early abstinence, which may contribute to an increased relapse risk after detoxification. Brain imaging studies on visuospatial WM in alcohol-dependent patients compared to controls indicate that information processing requires compensatory increased neural activation to perform at a normal level. However, to date, no study tested whether such increased neural WM activation patterns or the lack thereof predict relapse behavior in alcohol-dependent individuals, and whether such differences persist when adequately correcting for individual grey matter differences. We combined analyses of neural activation during an n-back task and local grey matter volumes using Biological Parametric Mapping in 40 detoxified alcohol-dependent patients and 40 matched healthy controls (HC), and assessed prospective relapse risk during a 7-month follow-up period. Despite equal task performance, we found increased functional activation during high versus low cognitive WM load (2-back-0-back) in bilateral rostral prefrontal cortex (BA10) and bilateral ventrolateral prefrontal cortex (BA45,47) in prospective abstainers versus relapsers, and further in left/right lateral/medial premotor cortex (BA6,8) in abstainers versus HC. In prospective abstainers, but not relapsers, subtle cognitive impairment was associated with increased neural task activity in the premotor cortex. These findings suggest that in prospective abstainers, higher functional engagement of presumably less impaired neural resources in executive behavioral control brain areas (BA10, 45, 47, 6, 8) may constitute a resilience factor associated with good treatment outcome.

Volumetric differences in the anterior cingulate cortex prospectively predict alcohol-related problems in adolescence

RATIONALE

Individual differences in brain structure and function are suggested to exist prior to the onset of alcohol abuse. Cross-sectional studies have demonstrated abnormalities in brain regions underlying affective processes that may form a pathway to the emergence of later alcohol abuse and dependence in vulnerable individuals. However, no prospective studies have examined whether these abnormalities predict later problems with alcohol.

OBJECTIVE

This study aims to examine whether individual differences in affect and brain volume prospectively predict alcohol-related problems in adolescence.

METHOD

Adolescent drinkers (n = 98) were recruited from an ongoing prospective, longitudinal study examining adolescent emotional development. At age 12, participants underwent structural magnetic resonance imaging to obtain volumetric data on the amygdala, hippocampus, orbitofrontal cortex, and anterior cingulate cortex (ACC), and completed a self-report measure of affective temperament. At age 16, participants completed a questionnaire measuring alcohol use, with 39 % reporting alcohol-related problems in the past year.

RESULTS

Pre-existing differences in the left ACC predicted problem drinking. Alcohol-related problems were associated with higher levels of temperamental negative affectivity; however, these were not correlated with anterior cingulate volumes.

CONCLUSIONS

These findings indicate that individual differences in the structural morphology of the anterior cingulate, a region implicated in affective processes, self-control, and drug addiction, predict later alcohol-related problems. Although this finding remained significant after controlling for other substance use and psychopathology, future research is required to test its specificity for alcohol use disorders.

Contributions of magnetic resonance spectroscopy to understanding development: potential applications in the study of adolescent alcohol use and abuse

A growing body of research has documented structural and functional brain development during adolescence, yet little is known about neurochemical changes that occur during this important developmental period. Magnetic resonance spectroscopy (MRS) is a well-developed technology that permits the in vivo quantification of multiple brain neurochemicals relevant to neuronal health and functioning. However, MRS technology has been underused in exploring normative developmental changes during adolescence and the onset of alcohol and drug use and abuse during this developmental period. This review begins with a brief overview of normative cognitive and neurobiological development during adolescence, followed by an introduction to MRS principles. The subsequent sections provide a comprehensive review of the existing MRS studies of development and cognitive functioning in healthy children and adolescents. The final sections of this article address the potential application of MRS in identifying neurochemical predictors and consequences of alcohol use and abuse in adolescence. MRS studies of adolescent populations hold promise for advancing our understanding of neurobiological risk factors for psychopathology by identifying the biochemical signatures associated with healthy brain development, as well as neurobiological and cognitive correlates of alcohol and substance use and abuse.

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.

Cognition, emotion, and attention

Deficits of attention, emotion, and cognition occur in individuals with alcohol abuse and addiction. This review elucidates the concepts of attention, emotion, and cognition and references research on the underlying neural networks and their compromise in alcohol use disorder. Neuroimaging research on adolescents with family history of alcoholism contributes to the understanding of pre-existing brain structural conditions and characterization of cognition and attention processes in high-risk individuals. Attention and cognition interact with other brain functions, including perceptual selection, salience, emotion, reward, and memory, through interconnected neural networks. Recent research reports compromised microstructural and functional network connectivity in alcoholism, which can have an effect on the dynamic tuning between brain systems, e.g., the frontally based executive control system, the limbic emotion system, and the midbrain-striatal reward system, thereby impeding cognitive flexibility and behavioral adaptation to changing environments. Finally, we introduce concepts of functional compensation, the capacity to generate attentional resources for performance enhancement, and brain structure recovery with abstinence. An understanding of the neural mechanisms of attention, emotion, and cognition will likely provide the basis for better treatment strategies for developing skills that enhance alcoholism therapy adherence and quality of life, and reduce the propensity for relapse.

The effect of alcohol use on human adolescent brain structures and systems

This article reviews the neurocognitive and neuroimaging literature regarding the effect of alcohol use on human adolescent brain structure and function. Adolescents who engage in heavy alcohol use, even at subdiagnostic levels, show differences in brain structure, function, and behavior when compared with non-drinking controls. Preliminary longitudinal studies have helped disentangle premorbid factors from consequences associated with drinking. Neural abnormalities and cognitive disadvantages both appear to predate drinking, particularly in youth who have a family history of alcoholism, and are directly related to the neurotoxic effect of alcohol use. Binge drinking and withdrawal and hangover symptoms have been associated with the greatest neural abnormalities during adolescence, particularly in frontal, parietal, and temporal regions.

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.

Family history of alcohol dependence modulates functional neurophysiology in mood/anxiety disorders

BACKGROUND

A family history (FH) of alcohol dependence (AD) not only increases the risk for AD, but is also associated with an increased risk for mood and anxiety disorders. However, it is unknown how a FH of AD affects neural substrates in patients with mood and anxiety disorders. In this study we examined the effects of an alcoholic FH on cognitive and emotional functions in these patients using functional magnetic resonance imaging (fMRI). Method In a sample of non-alcoholic patients with depressive and/or anxiety disorders from the Netherlands Study of Depression and Anxiety (NESDA) neuroimaging study, patients with a first-degree FH of AD (FH + ; n = 31) were compared with patients without a FH (FH-; n = 77) on performance and brain activation during visuospatial planning and emotional word encoding. Results were compared with those of healthy controls (HCs) without a FH of AD (n = 31).

RESULTS

FH+ patients performed slower during planning with increasing task load, coupled with stronger blood oxygen level-dependent responses in dorsal prefrontal areas compared with FH- patients and HCs. FH was not associated with performance differences during word encoding, but right insula activation during positive word encoding was present in FH+ patients, comparable with HCs, but absent in FH- patients.

CONCLUSIONS

This study demonstrates subtle impairments during planning in FH+ compared with FH- patients and HCs, whereas activation during mood-incongruent stimuli in FH+ patients was similar to HCs but not FH- patients, suggesting that the presence of a FH of AD is a useful marker for the neurophysiological profile in mood/anxiety disorders and possible predictor for treatment success.

Brain response to working memory over three years of adolescence: influence of initiating heavy drinking

OBJECTIVE

Many adolescents engage in heavy alcohol use. The aim of this study was to disentangle whether brain abnormalities seen in adolescent heavy drinkers are a consequence of heavy drinking, a preexisting risk factor for initiation of alcohol use, or both.

METHOD

Study 1 used cross-sectional functional magnetic resonance imaging (fMRI) visual working-memory (VWM) data from 15- to 19-year-olds (20 heavy drinkers, 20 controls) to identify brain regions affected by heavy adolescent alcohol use. Study 2 used longitudinal fMRI VWM data from 12- to 16-year-olds imaged before the onset of drinking and imaged again on the same scanner approximately 3 years later. Those who had transitioned into heavy drinking (n = 20) were matched to continuous nondrinkers (n = 20) on baseline alcohol risk and developmental factors (N = 40; 80 scans).

RESULTS

Study 1 found that heavy drinkers exhibited more frontal and parietal but less occipital activation than controls, defining the regions of interest for Study 2. In Study 2, adolescents who later transitioned into heavy drinking showed less fMRI response contrast at baseline than continuous nondrinkers, which increased after the onset of heavy drinking, in frontal (1,431 μL, p = .003; η² = .19) and parietal (810 μL, p = .005; η²= .23) regions, as in Study 1. Lower baseline activation in the frontal and parietal regions predicted subsequent substance use, more so than commonly observed predictors of youth drinking (p < .05).

CONCLUSIONS

Adolescents who initiated heavy drinking showed different brain activation before the onset of drinking, then less efficient information processing after high-dose alcohol use started. This suggests neural response patterns that could be risk factors for future substance use and also supports prior neuropsychological reports indicating that initiating heavy episodic drinking in adolescence may be followed by subtle alterations in brain functioning.

White matter microstructure, alcohol exposure, and familial risk for alcohol dependence

Offspring from families with alcohol dependence (AD) have been shown to exhibit brain morphological alterations that appear to be related to their familial/genetic risk for AD. Greater susceptibility for developing AD may be related to structural underpinnings of behavioral traits that predispose to AD. We examined white matter (WM) integrity in 81 individuals with either a high density of AD in their families (N=44) or without a family history for either alcohol or drug dependence (N=37). Magnetic resonance images were acquired on a Siemens 3 T scanner with fractional anistropy (FA) and the apparent diffusion coefficient (ADC), along with radial diffusivity (RD) and longitudinal (axial) diffusivity calculated for major white matter tracts in both hemispheres. Extensive personal histories of alcohol and drug use were available from longitudinal collection of data allowing for reliable estimates of alcohol and drug exposure. We found that the interaction of personal exposure to alcohol and familial risk for AD predicts reduction in WM integrity for the inferior longitudinal fasciculus (ILF) and the superior longitudinal fasciculus (SLF) in the left hemisphere and the forceps major tract. Only one tract showed a significant difference for exposure alone, the anterior thalamic radiation.

Atypical neural activity during inhibitory processing in substance-naïve youth who later experience alcohol-induced blackouts

BACKGROUND

Alcohol-induced blackouts are associated with the development of alcohol abuse and dependence, so it is important to consider potential neurobiological risk factors for experiencing this problem prior to the onset of substance use. This study examines whether neural activity during inhibitory processing might be atypical in substance-naïve youth who later experience alcohol-induced blackouts.

METHODS

We examined inhibitory processing during fMRI with a go/no-go task that requires withholding a prepotent response in substance-naïve youth who would later transition into heavy drinking (n=40) and youth who remain abstinent (n=20). After approximately 5 years of annual follow-up assessments, youth were classified as nondrinkers (n=20), and heavy drinking youth were classified as having experienced an alcohol-induced blackout (blackout+; n=20) or not (blackout-; n=20). Groups were matched on demographic variables, and youth who experienced blackouts were matched on follow-up substance use.

RESULTS

Prior to initiating substance use, blackout+ youth showed greater activation during inhibitory processing than nondrinkers and blackout- youth in frontal and cerebellar brain regions. Mean activation during correct inhibitory responses relative to go responses in the left and right middle frontal gyri at baseline predicted future blackout experience, after controlling for follow-up externalizing behaviors and lifetime alcohol consumption.

CONCLUSIONS

Substance-naïve adolescents who later experience alcohol-induced blackouts show increased neural effort during inhibitory processing, as compared to adolescents who go on to drink at similar levels but do not experience blackouts and healthy, nondrinking controls, suggesting a neurobiological vulnerability to alcohol-induced memory impairments.

A functional magnetic resonance imaging study of spatial working memory in children with prenatal alcohol exposure: contribution of familial history of alcohol use disorders

BACKGROUND

Heavy prenatal alcohol exposure leads to widespread cognitive deficits, including problems with spatial working memory (SWM). Neuroimaging studies report structural and functional abnormalities in fetal alcohol spectrum disorders (FASD), but interpretations may be complicated by the co-occurrence of a family history of alcoholism. Since this history is also linked to cognitive deficits and brain abnormalities, it is difficult to determine the extent to which deficits are unique to prenatal alcohol exposure.

METHODS

Age-matched subjects selected from 2 neuroimaging studies underwent functional imaging while engaging in a task assessing memory for spatial locations relative to a vigilance condition assessing attention. Pairwise comparisons were made for the following 3 groups: children with histories of heavy prenatal alcohol exposure (ALC, n = 18); those with no prenatal alcohol exposure, but a confirmed family history of alcoholism (FHP, n = 18); and nonexposed, family history negative controls (CON, n = 17).

RESULTS

Relative to CON and FHP, the ALC group showed increased blood oxygen level dependent (BOLD) response in the left middle and superior frontal gyri for the SWM condition relative to the vigilance condition (SWM contrast). Additionally, the ALC group showed unique BOLD response increases in the left lingual gyrus and right middle frontal gyrus relative to CON, and left cuneus and precuneus relative to FHP. Both ALC and FHP showed greater activation compared to CON in the lentiform nucleus and insular region.

CONCLUSIONS

These results confirm previous studies suggesting SWM deficits in FASD. Differences between the ALC group and the CON and FHP groups suggest the left middle and superior frontal region may be specifically affected in alcohol-exposed children. Conversely, differences from the CON group in the lentiform nucleus and insular region for the ALC and FHP groups may indicate this region is associated with family history of alcoholism rather than specifically with prenatal alcohol exposure.

Dare to delay? The impacts of adolescent alcohol and marijuana use onset on cognition, brain structure, and function

Throughout the world, drug and alcohol use has a clear adolescent onset (Degenhardt et al., 2008). Alcohol continues to be the most popular drug among teens and emerging adults, with almost a third of 12th graders and 40% of college students reporting recent binge drinking (Johnston et al., 2009, 2010), and marijuana (MJ) is the second most popular drug in teens (Johnston et al., 2010). The initiation of drug use is consistent with an overall increase in risk-taking behaviors during adolescence that coincides with significant neurodevelopmental changes in both gray and white matter (Giedd et al., 1996a; Paus et al., 1999; Sowell et al., 1999, 2002, 2004; Gogtay et al., 2004; Barnea-Goraly et al., 2005; Lenroot and Giedd, 2006). Animal studies have suggested that compared to adults, adolescents may be particularly vulnerable to the neurotoxic effects of drugs, especially alcohol and MJ (see Schneider and Koch, 2003; Barron et al., 2005; Monti et al., 2005; Cha et al., 2006; Rubino et al., 2009; Spear, 2010). In this review, we will provide a detailed overview of studies that examined the impact of early adolescent onset of alcohol and MJ use on neurocognition (e.g., Ehrenreich et al., 1999; Wilson et al., 2000; Tapert et al., 2002a; Hartley et al., 2004; Fried et al., 2005; Townshend and Duka, 2005; Medina et al., 2007a; McQueeny et al., 2009; Gruber et al., 2011, 2012; Hanson et al., 2011; Lisdahl and Price, 2012), with a special emphasis on recent prospective longitudinal studies (e.g., White et al., 2011; Hicks et al., 2012; Meier et al., 2012). Finally, we will explore potential clinical and public health implications of these findings.

Neurotoxic effects of alcohol in adolescence

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.

Neurotoxic effects of alcohol in adolescence

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.

Atypical spatial working memory and task-general brain activity in adolescents with a family history of alcoholism

BACKGROUND

Altered behavioral performance and brain activation during spatial working memory (SWM) tasks have been demonstrated in individuals with an alcohol use disorder (AUD). It is possible that alterations in processing during SWM may be present prior to initiation of heavy alcohol use in adolescents with a family history of AUDs (family history positive [FHP]) and therefore represent a premorbid neural phenotype that could increase risk for developing an AUD. The goal of our study was to investigate group differences in brain activation during a SWM task between FHP adolescents and adolescents with no family history of AUDs (family history negative [FHN]), as well as examine the relationship between brain activation and individual differences in family history density (FHD) of AUDs.

METHODS

Eighteen FHP and 16 gender and age-matched FHN participants completed a SWM and vigilance task while undergoing a functional magnetic resonance imaging (fMRI) scan.

RESULTS

There were no group differences in task performance. The FHN group demonstrated expected greater activation during the SWM than vigilance condition in the right middle frontal gyrus and dorsolateral prefrontal cortex, whereas the FHP group demonstrated comparable brain activation for both the more demanding and simple task conditions. Additionally, FHD was associated with greater activation of the right superior parietal cortex and less activation of the right cerebellum during the SWM task, but not during the vigilance task.

CONCLUSIONS

Results suggest FHP adolescents demonstrate alterations in activation of prefrontal regions that are related more generally to the maintenance of top-down cognitive control and alterations in parietal and cerebellar regions that are specific to SWM. Alterations in top-down cognitive control may be a general risk factor for FHP adolescents, whereas SWM-specific alterations are seen as a function of family history loading.

Increased marijuana use and gender predict poorer cognitive functioning in adolescents and emerging adults

This study sought to characterize neuropsychological functioning in MJ-using adolescents and emerging adults (ages 18-26) and to investigate whether gender moderated these effects. Data were collected from 59 teens and emerging adults including MJ users (n = 23, 56% female) and controls (n = 35, 50% female) aged 18-26 (M = 21 years). Exclusionary criteria included independent Axis I disorders (besides SUD), and medical and neurologic disorders. After controlling for reading ability, gender, subclinical depressive symptoms, body mass index, and alcohol and other drug use, increased MJ use was associated with slower psychomotor speed/sequencing ability (p < .01), less efficient sustained attention (p < .05), and increased cognitive inhibition errors (p < .03). Gender significantly moderated the effects of MJ on psychomotor speed/sequencing ability (p < .003) in that males had a more robust negative relationship. The current study demonstrated that MJ exposure was associated with poorer psychomotor speed, sustained attention and cognitive inhibition in a dose-dependent manner in young adults, findings that are consistent with other samples of adolescent MJ users. Male MJ users demonstrated greater cognitive slowing than females. Future studies need to examine the neural substrates underlying with these cognitive deficits and whether cognitive rehabilitation or exercise interventions may serve as a viable treatments of cognitive deficits in emerging adult MJ users.

Atypical frontal lobe activity during verbal working memory in youth with a family history of alcoholism

BACKGROUND

Abnormal brain functioning during verbal working memory (VWM) tasks has been shown in individuals with alcohol use disorders (AUDs). Since adolescents with a familial history of alcoholism (FHP) are at high risk for developing an AUD, it is important to consider whether atypical brain activity during VWM may help to explain FHP vulnerability toward developing alcoholism.

METHODS

To that end, using functional magnetic resonance imaging, we examined brain response during a VWM 2-back task in 19 FHP adolescents and 16 age and gender-matched family history negative (FHN) controls.

RESULTS

Despite no group differences in task accuracy, FHP youth had significantly slower average reaction time when making correct responses during the 2-back condition than FHN youth. In contrast to a vigilance control condition, while covarying for reaction time, FHP adolescents showed less activation during VWM than FHN youth in multiple areas of the prefrontal cortex (PFC)--a brain region crucial to intact working memory skills.

CONCLUSIONS

These results suggest that even prior to heavy alcohol use, FHP adolescents show atypical executive brain functioning during VWM, and that these differences are independent of slower working memory reaction time in FHP youth. Given the importance of working memory in numerous areas of day-to-day functioning, such as adaptive decision-making, these abnormalities may contribute to FHP youth vulnerability toward developing AUDs.

Resiliency in adolescents at high risk for substance abuse: flexible adaptation via subthalamic nucleus and linkage to drinking and drug use in early adulthood

INTRODUCTION

The personality trait resiliency is the ability to flexibly adapt impulse control relative to contextual demand. Low resiliency has been linked to later alcohol/drug problems. The underlying psychological and neural mechanisms are unknown, but neurocomputational models suggested relations between resiliency and working memory. Cortical-striatal connectivity has been proposed to underlie adaptive switches between cautious and risky behaviors.

METHODS

Working memory was probed in sixty-seven 18- to 22-year-olds from a larger community study of alcoholism, using the n-back task during functional magnetic resonance imaging. Functional connectivity between task-related regions was investigated with psychophysiological interaction analysis. Resiliency was measured in early teen years and related to early adulthood measures of drinking/drug use, task activation, and connectivity. Relationships with risk factors, including family history, age of drinking onset, and number of alcohol problems, were also investigated.

RESULTS

Higher resiliency was related to lower levels of substance use, fewer alcohol problems, and better working memory performance. Whole-brain regression revealed resiliency negatively correlated with activation of subthalamic nucleus (STN) and pallidum during the n-back. High and Low resiliency quartile groups (n = 17 each) differed in coupling strength between STN and median cingulate cortex, a region of reduced activation during working memory. The high resiliency group had later onset of drinking, fewer alcohol problems, had used fewer illicit drugs, and were less likely to smoke cigarettes than their low resiliency counterparts.

CONCLUSIONS

These findings suggest that resiliency in early adolescence may protect against alcohol problems and drug use, although the direction of this effect is currently unknown. This protective factor may relate to executive functioning as supported by the finding of a neural link shared between resiliency and working memory in basal ganglia structures. The STN, a key basal ganglia structure, may adaptively link flexible impulse control with cognitive processing, potentially modulating substance use outcomes.

Acute alcohol effects on contextual memory BOLD response: differences based on fragmentary blackout history

BACKGROUND

Contextual memory, or memory for source details, is an important aspect of episodic memory and has been implicated in alcohol-induced fragmentary blackouts (FBs). Little is known, however, about how neural functioning during contextual memory processes may differ between individuals with and without a history of FB. This study examined whether neural activation during a contextual memory task differed by history of FB and acute alcohol consumption.

METHODS

Twenty-four matched individuals with (FB+; n = 12) and without (FB-; n = 12) a history of FBs were recruited from a longitudinal study of alcohol use and behavioral risks and completed a laboratory beverage challenge followed by 2 functional magnetic resonance imaging (fMRI) sessions under no alcohol and alcohol (breath alcohol concentration = 0.08%) conditions. Task performance and brain hemodynamic activity during a block design contextual memory task were examined across 48 fMRI sessions.

RESULTS

Groups demonstrated no differences in performance on the contextual memory task, yet exhibited different brain response patterns after alcohol intoxication. A significant FB group by beverage interaction emerged in bilateral dorsolateral prefrontal cortex and posterior parietal cortex with FB- individuals showing greater blood oxygenation level-dependent response after alcohol exposure (p < 0.05).

CONCLUSIONS

Alcohol had differential effects on neural activity for FB+ and FB- individuals during recollection of contextual information, perhaps suggesting a neurobiological mechanism associated with alcohol-induced FB.

Risky decision-making: an FMRI study of youth at high risk for alcoholism

BACKGROUND

Adolescents with a family history of alcoholism (FHP) are at risk for developing an alcohol use disorder (AUD), and some studies indicate that FHP individuals show deficits in executive functioning. The ability to make adaptive decisions is one aspect of successful executive functioning that is often measured during risk-taking tasks; however, this behavior has not been examined in FHP youth. As impaired decision-making could predispose FHP youth to make poor choices related to alcohol use, the current study examined the neural substrates of risk-taking in FHP adolescents and their family history negative (FHN) peers.

METHODS

Thirty-one (18 FHP, 13 FHN) youth between 13 and 15 years old were included in this study. All youth had used little to no alcohol prior to study involvement. Functional magnetic resonance imaging was used to examine the neural substrates of risk-taking during the Wheel of Fortune (WOF) decision-making task (Ernst et al., 2004) in FHP and FHN youth.

RESULTS

FHP youth did not differ from FHN youth in risk-taking behavior, but showed less brain response during risky decision-making in right dorsolateral prefrontal cortex and right cerebellar regions compared with FHN peers.

CONCLUSIONS

Despite no behavioral differences on the WOF decision-making task, FHP youth exhibited atypical neural response during risk-taking compared with FHN peers. Atypical brain activity, in regions implicated in executive functioning could lead to reduced cognitive control, which may result in risky choices regarding alcohol use. This could help explain the higher rates of AUDs seen in FHP adolescents. Further examination of risky behavior and associated brain response over the course of adolescence is necessary to characterize the vulnerabilities of FHP youth in the absence of alcohol abuse.

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

Alcohol use typically is initiated during adolescence, a period that coincides with critical structural and functional maturation of the brain. Brain maturation and associated improvements in decision making continue into the third decade of life, reaching a plateau within the period referred to as emerging adulthood (18-24 years). This particular period covers that of traditionally aged college students, and includes the age (21 years) when alcohol consumption becomes legal in the United States. This review highlights neurobiological evidence indicating the vulnerabilities of the emerging-adult brain to the effects of alcohol. Factors increasing the risks associated with underage alcohol use include the age group's reduced sensitivity to alcohol sedation and increased sensitivity to alcohol-related disruptions in memory. On the individual level, factors increasing those risks are a positive family history of alcoholism, which has a demonstrated effect on brain structure and function, and emerging comorbid psychiatric conditions. These vulnerabilities-of the age group, in general, as well as of particular individuals-likely contribute to excessive and unsupervised drinking in college students. Discouraging alcohol consumption until neurobiological adulthood is reached is important for minimizing alcohol-related disruptions in brain development and decision-making capacity, and for reducing the negative behavioral consequences associated with underage alcohol use.

Neural activation during inhibition predicts initiation of substance use in adolescence

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.

Do executive and reactive disinhibition mediate the effects of familial substance use disorders on adolescent externalizing outcomes?

The present study examined the potential mediating roles of executive and reactive disinhibition in predicting conduct problems, attention-deficit/hyperactivity disorder (ADHD) symptoms, and substance use among adolescents with and without a family history of substance use disorders. Using data from 247 high-risk adolescents, parents, and grandparents, structural equation modeling indicated that reactive disinhibition, as measured by sensation seeking, mediated the effect of familial drug use disorders on all facets of the adolescent externalizing spectrum. Executive disinhibition, as measured by response disinhibition, spatial short term memory, and "trait" impulsivity, was associated with ADHD symptoms. Moreover, although executive functioning weakness were unrelated to familial substance use disorders, adolescents with familial alcohol use disorders were at risk for "trait" impulsivity marked by a lack of planning. These results illustrate the importance of "unpacking" the broad temperament style of disinhibition and of studying the processes that underlie the commonality among facets of the externalizing spectrum and processes that predict specific externalizing outcomes.

Frontoparietal connectivity in substance-naïve youth with and without a family history of alcoholism

Frontoparietal connections underlie key executive cognitive functions. Abnormalities in the frontoparietal network have been observed in chronic alcoholics and associated with alcohol-related cognitive deficits. It remains unclear whether neurobiological differences in frontoparietal circuitry exist in substance-naïve youth who are at-risk for alcohol use disorders. This study used functional connectivity magnetic resonance imaging and diffusion tensor imaging to examine frontoparietal connectivity and underlying white matter microstructure in 20 substance-naïve youth with a family history of alcohol dependence and 20 well-matched controls without familial substance use disorders. Youth with a family history of alcohol dependence showed significantly less functional connectivity between posterior parietal and dorsolateral prefrontal seed regions (ps<.05), as compared to family history negative controls; however, they did not show differences in white matter architecture within tracts subserving frontoparietal circuitry (ps>.34). Substance-naïve youth with a family history of alcohol dependence show less frontoparietal functional connectivity in the absence of white matter microstructural abnormalities as compared to youth with no familial risk. This may suggest a potential neurobiological marker for the development of substance use disorders.

Adolescents at risk for alcohol abuse demonstrate altered frontal lobe activation during Stroop performance

BACKGROUND

Children and adolescents, family history positive (FH+) for alcoholism, exhibit differences in brain structure and functional activation when compared to family history negative (FH-) counterparts. Given that frontal brain regions, and associated reciprocal connections with limbic structures, undergo the most dramatic maturational changes during adolescence, the objective of this study was to compare functional brain activation during a frontally mediated test of response inhibition in 32 adolescents separated into low-risk (FH-) and high-risk (FH+) groups.

METHODS

Functional magnetic resonance (fMRI) blood oxygen level-dependent data were acquired at 1.5 Tesla during performance of Stroop Color Naming, Word Reading, and Interference. Preprocessing and statistical analyses, covaried for age, were conducted in SPM99 using a search territory that included superior, middle, and inferior frontal gyri (trigone region), anterior cingulate gyrus (CG), and left and right amygdala.

RESULTS

Significantly greater activation in the fronto-limbic search territory was observed in FH+ relative to FH- subjects during Stroop Interference. In addition, a significant regression between brain activation and family history density was observed, with a greater density being associated with increased activation in regions including middle frontal gyrus (BA9) and CG (BA24).

CONCLUSIONS

These data demonstrate a significant influence of FH status on brain activation during the performance of a response inhibition task, perhaps reflecting a neurobiological vulnerability associated with FH status that may include reduced neuronal efficiency and/or recruitment of additional neuronal resources. These findings are important given that the adolescent developmental period is already associated with reduced inhibitory capacity, even prior to the onset of alcohol use.

Striatal dysfunction marks preexisting risk and medial prefrontal dysfunction is related to problem drinking in children of alcoholics

BACKGROUND

Parental alcoholism substantially raises risk for offspring alcoholism, an effect thought to be mediated by a dysregulation in impulse control. Adult alcoholics have alterations in the frontostriatal system involved in regulating impulsive responses. However, it remains controversial whether these alterations reflect preexisting traits predisposing to problem alcohol use or are secondary to alcohol involvement.

METHODS

Sixty-one 16 to 22 year olds were tested using a go/no-go task during functional magnetic resonance imaging. Forty-one were family history positive (FH+), having at least one parent with a diagnosis of alcohol use disorder (AUD), and 20 were family history negative (FH-). Two FH+ subgroups were created to disentangle alcohol involvement from preexisting risk: the FH+ control group (n = 20) had low alcohol problems, differing from the FH- group only by family history. The FH+ problem group (n = 21) had high alcohol problems.

RESULTS

The ventral caudate deactivated during successful inhibition in the FH- but not the FH+ groups, regardless of problem alcohol involvement. Regression analyses showed that ventral caudate deactivation was related to fewer externalizing problems as well as to family history. Orbital and left medial prefrontal regions were deactivated in both the FH- and FH+ control groups but not the FH+ problem group. Activation in these regions was associated with alcohol and other drug use.

CONCLUSIONS

These findings suggest a preexisting abnormality in ventral striatal function in youth at risk for AUD, which may lead to inappropriate motivational responding, and suggest that with alcohol use, the prefrontal "control" mechanism loses efficiency, further dysregulating the frontostriatal motivational circuitry.

Neural circuitry associated with risk for alcohol use disorders

The core features of risk for alcohol use disorders (AUD), including behavioral disinhibition, affective dysregulation, and executive dysfunction, map onto distinct neural circuits that have been found to be abnormal in the offspring of alcohol dependent individuals. Components of the cerebellothalamocortical system and the extended limbic network may provide the underpinnings for the behavioral and emotional dysfunction observed in individuals at heightened risk for AUD. In addition, abnormalities in these structures appear to be altered in individuals with the predisposition for other psychiatric conditions that may share a similar genetic diathesis. This review proposes several neurobehavioral mechanisms of genetic vulnerability that may account for phenotypic characteristics in individuals at risk for AUD.

Alcohol cue reactivity task development

BACKGROUND

The physiological and cognitive reactions provoked by alcohol cues, as compared to non-alcohol cues, can predict future drinking. Alcohol cue reactivity tasks have been developed; however, most were created for use with alcohol use disordered individuals and utilize limited or only partially standardized stimuli. This project systematically created an alcohol cue reactivity task for studies with non-drinkers, using well-characterized stimuli.

OBJECTIVES

We comprehensively standardized 60 alcohol and 60 non-alcohol beverage pictures using ratings from young non-drinkers (N=82) on affective and perceptual features.

RESULTS

A statistical matching approach yielded 26 matched alcohol-non-alcohol picture pairs matched on valence, arousal, image complexity, brightness, and hue. The task was piloted and further refined to 22 picture pairs. An 8-minute, 32-second event-related task was created using a random stimulus function for optimized condition timing and systematic presentation of the images.

CONCLUSIONS

The long-term objectives of this project are to utilize this task with non-drinking youth to investigate how reactivity to alcohol stimuli may predict alcohol use initiation and escalation, to help identify the role of exposure to alcohol stimuli on the subsequent development of alcohol-related problems.

Family history of alcohol-use disorders and spatial working memory: effects on adolescent alcohol expectancies

OBJECTIVE

Family history (FH) of alcohol-use disorders (AUDs) has been associated with frontal lobe deficits, more positive expectations for alcohol effects, and increased risk of developing AUDs. We tested the hypothesis that anterior brain regions mediate the relationship between FH of AUDs and alcohol expectancies in adolescents.

METHOD

Nondrinking adolescents (N = 50) ages 12-14 completed measures of FH of AUDs, alcohol expectancies, and substance use and performed spatial working memory and vigilance tasks during functional magnetic resonance imaging.

RESULTS

Activation of the anterior cingulate significantly predicted alcohol expectancies (R(2)Delta = 9%, beta = .32, F(change) = 6.09, 1/43 df, p < .05). However, FH of AUDs was not associated with brain response or alcohol expectancies.

CONCLUSIONS

Although a mediational model was not supported, activation in the anterior cingulate was linked to alcohol expectancies, such that adolescents with less neural differentiation to task demands had more positive expectancies for alcohol's effects. These results provide a greater understanding of the interrelations among risk factors for AUD and point to individuals who might be targeted for early, cognitively based interventions.