Neuropsychological performance of South African treatment-naïve adolescents with alcohol dependence

Alcohol and stress exposure across the lifespan are key risk factors for Alzheimer's Disease and cognitive decline

Alzheimer's Disease and related dementias (ADRD) are an increasing threat to global health initiatives. Efforts to prevent the development of ADRD require understanding behaviors that increase and decrease risk of neurodegeneration and cognitive decline, in addition to uncovering the underlying biological mechanisms behind these effects. Stress exposure and alcohol consumption have both been associated with increased risk for ADRD in human populations. However, our ability to understand causal mechanisms of ADRD requires substantial preclinical research. In this review, we summarize existing human and animal research investigating the connections between lifetime stress and alcohol exposures and ADRD.

BDNF and its Role in the Alcohol Abuse Initiated During Early Adolescence: Evidence from Preclinical and Clinical Studies

Brain-derived neurotrophic factor (BDNF) is a crucial brain signaling protein that is integral to many signaling pathways. This neurotrophin has shown to be highly involved in brain plastic processes such as neurogenesis, synaptic plasticity, axonal growth, and neurotransmission, among others. In the first part of this review, we revise the role of BDNF in different neuroplastic processes within the central nervous system. On the other hand, its deficiency in key neural circuits is associated with the development of psychiatric disorders, including alcohol abuse disorder. Many people begin to drink alcohol during adolescence, and it seems that changes in BDNF are evident after the adolescent regularly consumes alcohol. Therefore, the second part of this manuscript addresses the involvement of BDNF during adolescent brain maturation and how this process can be negatively affected by alcohol abuse. Finally, we propose different BNDF enhancers, both behavioral and pharmacological, which should be considered in the treatment of problematic alcohol consumption initiated during the adolescence.

Alcohol use is associated with mental health problems and brain structural alterations in adolescents with perinatally acquired HIV infection on ART

Alcohol use, presents unique challenges for HIV-1 treatment in adolescents with perinatally acquired infection. The effects of alcohol on host-virus interaction in the brain and the immune system remains understudied in this population. Adolescents with perinatally acquired HIV infection (PHIV) well established on ART, from the Cape Town Adolescent Antiretroviral Cohort who self-reported alcohol use (PHIV + alcohol) (n = 26) were compared to age matched 26 PHIV (PHIV-alcohol) and 26 healthy controls (HC) who reported no use of alcohol. Participants completed clinical investigations including highly-sensitive CRP (hs-CRP), a comprehensive neurocognitive test battery and mental health measures. In addition, we investigated the relationship between alcohol use in PHIV and diffusion tensor imaging (DTI) and structural brain magnetic resonance imaging (MRI) to determine fractional anisotropy (FA), mean diffusivity (MD), grey and white matter volumes and cortical thickness. PHIV (mean age 12,5 years; mean age of ART initiation 3.15 years) reported an occasional weekend drinking pattern of alcohol use. hs-CRP was significantly different between groups, with PHIV + alcohol higher than PHIV-alcohol and HC. General intelligence, attention, working memory, processing speed and executive function were more impaired in the PHIV + alcohol than PHIV alone, with HC having the highest scores. In addition, self-concept was significantly lower in PHIV + alcohol. The Child Behavior Checklist (CBCL) Externalizing behaviour, internalising behaviour and CBCL Total problems were significantly higher in PHIV + alcohol. FA of the superior corona radiata, superior fronto-occipital fasciculus and corpus callosum was significantly lower in PHIV + alcohol compared to PHIV-alcohol and MD of the corona radiata was significantly increased in PHIV + alcohol. The cortical thickness of the lateral orbitofrontal, middle frontal and precentral gyri were significantly lower in PHIV + alcohol compared to PHIV-alcohol and HC. In conclusion PHIV associated impairments in systemic inflammation, cognitive function, mental health and changes in brain structure may be exacerbated by alcohol use, even if only occasional use. However, the study is cross-sectional, which is not able to distinguish between cause and effect.

Cognitive insight is associated with perceived body weight in overweight and obese adults

Background

Accurate perception of body weight is necessary for individuals with a high body mass index (BMI) to initiate strategies to improve their health status. Furthermore, identifying factors that influence accurate body weight perception can assist in designing appropriate educational and weight management programs. We therefore aimed to investigate whether levels of cognitive functioning and insight influence the ability to correctly judge body weight.

Methods

One hundred and eighty four overweight and obese adults who participated in a cross- sectional case-control study and were controls in the aforementioned study were included. The study was conducted in Cape Town, South Africa. Demographic, weight-related, neuropsychiatric, neurocognitive and cognitive insight measures were administered. Regression analysis was conducted to determine the factors associated with correct weight perception.

Results

The final regression model explained 52.3% of variation in accurate perception of body weight and was significant (p ≤ 0. 001). The model correctly classified 79.3% of individuals who were able to correctly and incorrectly judge their weight. Adults with higher BMI, and lower self-certainty, those who reported that they had gained weight in the previous year and those who were told by a healthcare professional to lose or maintain a healthy weight were more likely to correctly judge their weight.

Conclusion

Some aspects of cognitive insight (self-certainty) but not cognitive functioning were associated with perception of body weight in this sample. Awareness of recent weight changes, higher BMI and advice from of health care professionals were also significantly associated with perception of body weight, while demographic variables were not. Understanding the factors that contribute to the correct perception of weight is important in identifying appropriate health interventions that may address the burden of associated non-communicable diseases in overweight and obese individuals.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-10559-5.

Implementation of an attention training programme with a sample of children who have sustained traumatic brain injuries in South Africa: A pilot study

This pilot study evaluated the feasibility of implementing an attention-training programme for children who have sustained moderate-to-severe traumatic brain injuries (TBIs) in a South African context. We compared the performance on the programme of children with TBI (TBI Intervention Group) to children who had been diagnosed with Attention Deficit Hyperactivity Disorder (ADHD Intervention Group), a TBI Art group and a TBI No-intervention Group (n=5 in each group) in this preliminary study. Children in the two Intervention Groups participated in the "Pay Attention!" programme for 45 minutes twice a week for 12 weeks. All children were aged 6-8 years and underwent neuropsychological testing pre- and post-intervention. Behavioural data were collected from parents. Children in the ADHD Intervention Group showed individual clinically significant attentional improvements on measures of the Conners' Continuous Performance Test II using the Reliable Change Index (≥ 2.58 SD). Despite mixed results, the pilot study demonstrates that implementing a cognitive rehabilitation programme in South Africa is feasible and necessary, despite limited infrastructure and access to resources.

Neuropsychological Trajectories Associated with Adolescent Alcohol and Cannabis Use: A Prospective 14-Year Study

OBJECTIVES

Alcohol and cannabis remain the substances most widely used by adolescents. Better understanding of the dynamic relationship between trajectories of substance use in relation to neuropsychological functioning is needed. The aim of this study was to examine the different impacts of within- and between-person changes in alcohol and cannabis use on neuropsychological functioning over multiple time points.

METHODS

Hierarchical linear modeling examined the effects of alcohol and cannabis use on neuropsychological functioning over the course of 14 years in a sample of 175 adolescents (aged 12-15 years at baseline).

RESULTS

Time-specific fluctuations in alcohol use (within-person effect) predicted worse performance across time on the Wechsler Abbreviated Scale of Intelligence Block Design subtest (B = -.05, SE = .02, p = .01). Greater mean levels of percent days of cannabis use across time (between-person effect) were associated with an increased contrast score between Delis-Kaplan Executive Function System Color Word Inhibition and Color Naming conditions (B = .52, SE = .14, p < .0001) and poorer performance over time on Block Design (B = -.08, SE = .04, p = .03). Neither alcohol and/nor cannabis use over time was associated with performance in the verbal memory and processing speed domains.

CONCLUSIONS

Greater cumulative cannabis use over adolescence may be linked to poorer inhibitory control and visuospatial functioning performance, whereas more proximal increases in alcohol consumption during adolescence may drive alcohol-related performance decrements in visuospatial functioning. Results from this prospective study add to the growing body of literature on the impact of alcohol and cannabis use on cognition from adolescent to young adulthood.

Neuropsychiatric and Neurocognitive Manifestations in HIV-Infected Children Treated With Efavirenz in South Africa-A Retrospective Case Series

Background: Efavirenz is associated with transient neuropsychiatric manifestations but the impact on neurocognition in children is unknown. Genetically slow metabolizers of efavirenz may be at risk of toxicity. This study describes neuropsychiatric and neurocognitive manifestations of South African children with suspected efavirenz neurotoxicity. Method: This retrospective study describes clinical features of 12 children with features consistent with efavirenz neurotoxicity between 2008 and 2014. Results: Twelve children (4 males, 8 females) aged 3-12 years (median 8.4 years) were referred to a dedicated pediatric neuroHIV service. Eight were of indigenous African (black) ancestry and 4 were of mixed ancestry. The total duration on efavirenz-containing ART at the time of referral was 6-72 (mean 31) months. Two children (both of black ancestry) were phenotypically slow metabolizers and presented with acute manifestations and high plasma efavirenz concentrations above normal range resulting in discontinuation of efavirenz. Ten other children had clinical presentations compatible with efavirenz neurotoxicity but had normal or sub-therapeutic plasma efavirenz concentrations and continued treatment with efavirenz. The acute neuropsychiatric manifestations reported included drowsiness, seizures, sleep disturbances, personality changes, ataxia, and slurred speech. These were noticed 2-8 weeks (mean 5 weeks) after commencing efavirenz and resolved over a few weeks. Nine children had neurocognitive deficits and showed poor performance in all neurocognitive domains that were tested. Interpretation: Efavirenz causes transient neuropsychiatric adverse effects and may contribute to poor long-term neurocognitive outcomes in HIV-infected children. Prospective studies comparing efavirenz-treated and efavirenz-naïve children are needed to further elucidate the manifestations of efavirenz toxicity.

Lower Prefrontal and Hippocampal Volume and Diffusion Tensor Imaging Differences Reflect Structural and Functional Abnormalities in Abstinent Individuals with Alcohol Use Disorder

BACKGROUND

Alcohol use disorder (AUD) is known to have adverse effects on brain structure and function. Multimodal assessments investigating volumetric, diffusion, and cognitive characteristics may facilitate understanding of the consequences of long-term alcohol use on brain circuitry, their structural impairment patterns, and their impact on cognitive function in AUD.

METHODS

Voxel- and surface-based volumetric estimations, diffusion tensor imaging (DTI), and neuropsychological tests were performed on 60 individuals: 30 abstinent individuals with AUD (DSM-IV) and 30 healthy controls. Group differences in the volumes of cortical and subcortical regions, fractional anisotropy (FA), axial and radial diffusivities (AD and RD, respectively), and performance on neuropsychological tests were analyzed, and the relationship among significantly different measures was assessed using canonical correlation.

RESULTS

AUD participants had significantly smaller volumes in left pars orbitalis, right medial orbitofrontal, right caudal middle frontal, and bilateral hippocampal regions, lower FA in 9 white matter (WM) regions, and higher FA in left thalamus, compared to controls. In AUD, lower FA in 6 of 9 WM regions was due to higher RD and due to lower AD in the left external capsule. AUD participants scored lower on problem-solving ability, visuospatial memory span, and working memory. Positive correlations of prefrontal cortical, left hippocampal volumes, and FA in 4 WM regions with visuospatial memory performance and negative correlation with lower problem-solving ability were observed. Significant positive correlation between age and FA was observed in bilateral putamen.

CONCLUSIONS

Findings showed specific structural brain abnormalities to be associated with visuospatial memory and problem-solving ability-related impairments observed in AUD. Higher RD in 6 WM regions suggests demyelination, and lower AD in left external capsule suggests axonal loss in AUD. The positive correlation between FA and age in bilateral putamen may reflect accumulation of iron depositions with increasing age.

Effects of adolescent alcohol consumption on the brain and behaviour

Per occasion, alcohol consumption is higher in adolescents than in adults in both humans and laboratory animals, with changes in the adolescent brain probably contributing to this elevated drinking. This Review examines the contributors to and consequences of the use of alcohol in adolescents. Human adolescents with a history of alcohol use differ neurally and cognitively from other adolescents; some of these differences predate the commencement of alcohol consumption and serve as potential risk factors for later alcohol use, whereas others emerge from its use. The consequences of alcohol use in human adolescents include alterations in attention, verbal learning, visuospatial processing and memory, along with altered development of grey and white matter volumes and disrupted white matter integrity. The functional consequences of adolescent alcohol use emerging from studies of rodent models of adolescence include decreased cognitive flexibility, behavioural inefficiencies and elevations in anxiety, disinhibition, impulsivity and risk-taking. Rodent studies have also showed that adolescent alcohol use can impair neurogenesis, induce neuroinflammation and epigenetic alterations, and lead to the persistence of adolescent-like neurobehavioural phenotypes into adulthood. Although only a limited number of studies have examined comparable measures in humans and laboratory animals, the available data provide evidence for notable across-species similarities in the neural consequences of adolescent alcohol exposure, providing support for further translational efforts in this context.

Earlier Alcohol Use Onset Predicts Poorer Neuropsychological Functioning in Young Adults

BACKGROUND

Neurodevelopment may be shaped by environmental factors such as alcohol intake. Over 20% of U.S. high school students begin drinking before age 14, and those who initiated drinking before age 14 are 4 times more likely to develop psychosocial, psychiatric, and substance use difficulties than those who began drinking after turning 20. Little is known, however, about how the age of alcohol use onset influences brain development.

METHODS

This study prospectively examined the effects of alcohol use onset age on neurocognitive functioning in healthy adolescent drinkers (N = 215). Youth were administered a neuropsychological battery before substance use initiation (M = 13.6 years, SD = 0.8) and on average 6.8 years later (M = 20.2 years, SD = 1.5). Hierarchical linear regressions examined if earlier ages of onset for first and regular (i.e., weekly) alcohol use adversely influenced neurocognition, above and beyond baseline neurocognition, substance use severity, and familial and social environment factors.

RESULTS

As hypothesized, an earlier age of first drinking onset (AFDO) predicted poorer performance in the domains of psychomotor speed and visual attention (ps<0.05, N = 215) and an earlier age of weekly drinking onset (AWDO) predicted poorer performances on tests of cognitive inhibition and working memory, controlling for baseline neuropsychological performance, drinking duration, and past-year marijuana use (ps<0.05, N = 127). No relationship between AFDO and AWDO was found with verbal learning and memory and visuospatial ability.

CONCLUSIONS

This is the first study to assess the association between age of adolescent drinking onset and neurocognitive performance using a comprehensive test battery. This study suggests that early onset of drinking increases risk for alcohol-related neurocognitive vulnerabilities and that initiation of any or weekly alcohol use at younger ages appears to be a risk factor for poorer subsequent neuropsychological functioning. Findings have important implications for public policies related to the legal drinking age and prevention programming. Further studies are needed to replicate these preliminary findings and better understand mediating processes and moderating conditions.

Binge drinking during adolescence and young adulthood is associated with deficits in verbal episodic memory

Binge drinking (BD), a harmful pattern of alcohol consumption, is common during adolescence. Young adults with alcohol use disorders exhibit hippocampal alterations and episodic memory deficits. However, it is not known how these difficulties progress in community BD adolescents. Our objective was to analyze the relationship between BD trajectory and verbal episodic memory during the developmental period spanning from adolescence and to early adulthood. An initial sample of 155 male and female first-year university students with no other risk factors were followed over six years. Participants were classified as stable non-BDs, stable BDs and ex-BDs according to the third AUDIT item. At baseline, participants comprised 36 ♂/ 40 ♀ non-BDs (18.58 years), 40 ♂/ 39 ♀ BDs (18.87 years), and at the third follow-up, they comprised 8 ♂/ 8 ♀ stable non-BDs (25.49 years), 2 ♂/ 2 ♀ stable BDs (25.40) and 8 ♂/ 12 ♀ ex-BDs (24.97 years). Episodic memory was assessed four times with the Logical Memory subtest (WMS-III) and the Rey Auditory Verbal Learning Test (RAVLT). Generalized linear mixed models were applied. The results showed that, relative to non-BDs, stable BDs presented difficulties in immediate and delayed recall in the Logical Memory subtest. These difficulties remained stable over time. The short-term ex-BDs continued to display difficulties in immediate and delayed recall in the Logical Memory subtest, but long-term ex-BDs did not. The effects were not influenced by age of alcohol onset, frequency of cannabis use, tobacco use or psychopathological distress. In conclusion, BD during adolescence and young adulthood is associated with episodic memory deficits. Abandoning the BD pattern may lead to partial recovery. These findings are consistent with the vulnerability of the adolescent hippocampus to the neurotoxic effects of alcohol.

Neuropsychology in South Africa: confronting the challenges of specialist practice in a culturally diverse developing country

OBJECTIVE

This was an invited paper on the history and current status of neuropsychology in South Africa.

METHOD

Information was gathered from literature searches, personal communication, and the authors' experiences while occupying relevant professional and academic positions for over 30 years.

RESULTS

Since its origins in the 1950s, the development of neuropsychology in South Africa has faced numerous challenges, against a background of extreme sociocultural and socioeconomic disparity in the country that is on-going. The creation of the South African Clinical Neuropsychological Society in the 1980s, a credentialing and training body, gave impetus to the discipline. In the absence of a neuropsychology category within the South African professional framework, university instruction has been ad hoc with vastly different levels of competency depending on the institution involved. The small number of practitioners and/or academics involved in neuropsychology includes mainly masters, and some doctoral level psychologists registered in clinical, counseling or educational categories. A prime emphasis of neuropsychological research has been local norming of psychometric tests to facilitate valid assessment practices in the country. South Africa is on the cusp of achieving a hard-won neuropsychology professional register. It is anticipated that this development will provide impetus to the discipline by promoting training programs, the creation of neuropsychology posts, wider service delivery, and increased research funding.

CONCLUSIONS

Despite significant challenges in a culturally diverse, developing country, neuropsychology has evolved sufficiently to warrant the creation of a separate category in the professional framework. This development will facilitate training, research, and services in the country.

Applying the HIV-associated neurocognitive disorder diagnostic criteria to HIV-infected youth

OBJECTIVE

The aim of this study was to apply the HIV-associated neurocognitive disorders (HAND) criteria for diagnosing HAND in HIV-infected adults, in a cohort of HIV-infected youth to thus establish whether this system is able to detect a spectrum of neurocognitive disorders (ND) in HIV-infected youth.

METHODS

We used a comprehensive pediatric neurocognitive battery, an assessment of functional competence, and the American Academy of Neurology system for diagnosing ND in a cross-sectional study of HIV-infected youth (n = 86) and HIV-negative controls (n = 34) to establish whether this system could detect a spectrum of ND in HIV-infected youth (6-16 years).

RESULTS

Compared to a well-matched control group of HIV-negative youth, HIV-infected youth performed significantly more poorly on tests of Verbal IQ, Full Scale IQ, processing speed, finger tapping, verbal memory, expressive language, cognitive flexibility, and inhibition. HIV-infected youth were also more likely to have impaired total competence on the Child Behavior Checklist. Using the criteria for HAND, we found that 45.35% of the 86 HIV-infected youth could be diagnosed with an ND. Furthermore, youth with HIV encephalopathy (HIVE) were 9.4 times more likely to have a diagnosis of a major ND compared to HIV-infected youth without HIVE.

CONCLUSIONS

The HAND criterion designed for adults was able to identify youth with important functional cognitive impairments who do not fit criteria for HIVE and would therefore not have been identified otherwise. This has major clinical implications regarding the importance of managing HIV-infected youth.

Low brain oxygenation and differences in neuropsychological outcomes following severe pediatric TBI

PURPOSE

Traumatic brain injury (TBI) is a leading cause of morbidity and mortality in children. Preventing secondary injury by controlling physiological parameters (e.g. intracranial pressure [ICP], cerebral perfusion pressure [CPP] and brain tissue oxygen [PbtO2]) has a potential to improve outcome. Low PbtO2 is independently associated with poor clinical outcomes in both adults and children. However, no studies have investigated associations between low PbtO2 and neuropsychological and behavioural outcomes following severe pediatric TBI (pTBI).

METHODS

We used a quasi-experimental case-control design to investigate these relationships. A sample of 11 TBI patients with a Glasgow Coma Scale score ≤8 who had PbtO2 and ICP monitoring at the Red Cross War Memorial Children's Hospital underwent neuropsychological evaluation ≥1 year post-injury. Their performance was compared to that of 11 demographically matched healthy controls. We then assigned each TBI participant into one of two subgroups, (1) children who had experienced at least one episode of PbtO2 ≤ 10 mmHg or (2) children for whom PbtO2 > 10 mmHg throughout the monitoring period, and compared their results on neuropsychological evaluation.

RESULTS

TBI participants performed significantly more poorly than controls in several cognitive domains (IQ, attention, visual memory, executive functions and expressive language) and behavioural (e.g. externalizing behaviour) domains. The PbtO2 ≤ 10 mmHg group performed significantly worse than the PbtO2 > 10 mmHg group in several cognitive domains (IQ, attention, verbal memory, executive functions and expressive language), but not on behavioural measures.

CONCLUSION

Results demonstrate that low PbtO2 may be prognostic of not only mortality but also neuropsychological outcomes.

Adolescent heavy drinkers' amplified brain responses to alcohol cues decrease over one month of abstinence

INTRODUCTION

Heavy drinking during adolescence is associated with increased reactivity to alcohol related stimuli and to differential neural development. Alcohol cue reactivity has been widely studied among adults with alcohol use disorders, but little is known about the neural substrates of cue reactivity in adolescent drinkers. The current study aimed to identify changes in blood-oxygen level dependent (BOLD) signal during a cue reactivity task pre- and post-monitored abstinence from alcohol.

METHOD

Demographically matched adolescents (16.0-18.9 years, 54% female) with histories of heavy episodic drinking (HD; n=22) and light or non-drinking control teens (CON; n=16) were recruited to participate in a month-long study. All participants completed a functional Magnetic Resonance Imaging (fMRI) scan with an alcohol cue reactivity task and substance use assessments at baseline and after 28 days of monitored abstinence from alcohol and drugs (i.e., urine toxicology testing every 48-72 h). Repeated-measure analysis of variance (ANOVA) examined main effects of group, time, and group×time interactions on BOLD signal response in regions of interest defined by functional differences at baseline.

RESULTS

The HD group exhibited greater (p<.01) BOLD activation than CON to alcohol cues relative to neutral cues in all regions of interest (ROIs; bilateral striatum/globus pallidus, left anterior cingulate, bilateral cerebellum, and parahippocampal gyrus extending to the thalamus/substantia nigra) across time points. Group×time effects showed that HD exhibited greater BOLD activation to alcohol cues than CON at baseline in left anterior cingulate cortex and in the right cerebellar region, but these decreased to non-significance after one month of monitored abstinence.

CONCLUSIONS

In all ROIs examined, HD exhibited greater BOLD response than CON to alcohol relative to neutral beverage picture cues at baseline, indicating heightened cue reactivity to alcohol cues in heavy drinking adolescents prior to the onset of any alcohol use diagnosis. Across the majority of these brain regions, differences in BOLD response were no longer apparent following a month of abstinence, suggesting a decrease in alcohol cue reactivity among adolescent non-dependent heavy drinkers as a consequence of abstaining from alcohol. These results highlight the malleability of adolescent brain function despite no formal intervention targeting cue reactivity. Increased understanding of the neural underpinnings of cue reactivity could have implications for prevention and intervention strategies in adolescent heavy alcohol users.

The cross-cultural utility of foreign- and locally-derived normative data for three WHO-endorsed neuropsychological tests for South African adolescents

Interpretation of neuropsychological tests may be hampered by confounding sociodemographic factors and by using inappropriate normative data. We investigated these factors in three tests endorsed by the World Health Organization: the Grooved Pegboard Test (GPT), the Children's Color Trails Test (CCTT), and the WHO/UCLA version of the Auditory Verbal Learning Test (AVLT). In a sample of 12-15-year-old, Afrikaans- and English-speaking adolescents from the Cape Town region of South Africa, analyses of covariance (ANCOVAs) demonstrated that quality of education was the sociodemographic factor with the biggest influence on test performance, and that age also significantly influenced GPT and CCTT performance. Based on those findings, we provide appropriately stratified normative data for the age group in question. Comparisons between diagnostic interpretations made using foreign normative data versus those using the current local data demonstrate that it is imperative to use appropriately stratified normative data to guard against misinterpreting performance.

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.

Cortical and subcortical volumes in adolescents with alcohol dependence but without substance or psychiatric comorbidities

Most prior studies of the effects of excessive alcohol intake on the adolescent brain examined alcohol-use-dependent samples with comorbid psychiatric and substance use disorders. In the Cape Town region, we identified a sizeable cohort of adolescents with alcohol use disorders (AUD) without externalizing or other psychiatric disorders. We examined brain morphology in 64 such adolescents compared to age- and gender-matched healthy controls. Magnetic resonance imaging data were analyzed using FSL's FIRST software for subcortical volumes, and cortical gray matter (GM) was analyzed using voxel-based morphometry (VBM) and regions of interest (ROI) analysis. AUD boys had smaller thalamic and putamen volumes compared to non-drinking boys, while AUD girls had larger thalamic and putamen volumes compared to non-drinking girls. VBM revealed a large region of decreased GM density in AUDs compared to controls located in the left lateral frontal, temporal, and parietal lobes, extending medially deep into the parietal lobe. Smaller GM volume in this region was also present when examined using ROI analysis. Our lack of findings in other brain regions, particularly the hippocampus, suggests that reports of smaller brain volumes in adolescent AUDs in the literature are a consequence of psychiatric and substance abuse comorbidities.

Alcohol Consumption and Executive Functions in Adolescents: A Systematic Review

Objetivo: el consumo de alcohol entre los estudiantes universitarios se ha convertido en una preocupación creciente en los últimosaños, por lo que este estudio fue desarrollado con el objetivo de identificar el consumo de esta sustancia entre los estudiantes de enfermería.Método: se trata de un estudio transversal desarrollado en una universidad privada en la ciudad de Río de Janeiro, Brasil, con 161estudiantes que respondieron a un cuestionario autoadministrado que contiene información sociodemográfica, preguntas seleccionadasdel Alcohol Use Disorders Identification Test y otros aspectos relacionados con el consumo de bebidas alcohólicas. Resultados: alta proporción(67,7 %) de los estudiantes de enfermería entrevistados reportó ser consumidores de alcohol, y el 32,1 % de ellos estaban en laorgía de consumo estándar, y casi la mitad (45,9 %) de los consumidores están expuestos al riesgo de desarrollar problemas relacionadoscon el consumo de esta sustancia. Resultados: están preocupados por el consumo de bebidas alcohólicas de los estudiantes de enfermeríaque participaron en este estudio, ya que son los futuros profesionales que inevitablemente actúan como educadores y motivadorespara la adopción de conductas saludables en la población. Conclusión: por lo tanto, se necesitan políticas y programas para prevenir elconsumo excesivo de alcohol en esta población.

A role for cognitive rehabilitation in increasing the effectiveness of treatment for alcohol use disorders

Neurocognitive impairments are prevalent in persons seeking treatment for alcohol use disorders (AUDs). These impairments and their physical, social, psychological and occupational consequences vary in severity across persons, much like those resulting from traumatic brain injury; however, due to their slower course of onset, alcohol-related cognitive impairments are often overlooked both within and outside of the treatment setting. Evidence suggests that cognitive impairments can impede treatment goals through their effects on treatment processes. Although some recovery of alcohol-related cognitive impairments often occurs after cessation of drinking (time-dependent recovery), the rate and extent of recovery is variable across cognitive domains and individuals. Following a long hiatus in scientific interest, a new generation of research aims to facilitate treatment process and improve AUD treatment outcomes by directly promoting cognitive recovery (experience-dependent recovery). This review updates knowledge about the nature and course of cognitive and brain impairments associated with AUD, including cognitive effects of adolescent AUD. We summarize current evidence for indirect and moderating relationships of cognitive impairment to treatment outcome, and discuss how advances in conceptual frameworks of brain-behavior relationships are fueling the development of novel AUD interventions that include techniques for cognitive remediation. Emerging evidence suggests that such interventions can be effective in promoting cognitive recovery in persons with AUD and other substance use disorders, and potentially increasing the efficacy of AUD treatments. Finally, translational approaches based on cognitive science, neurophysiology, and neuroscience research are considered as promising future directions for effective treatment development that includes cognitive rehabilitation.

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.

Event-Related Oscillations in Alcoholism Research: A Review

Alcohol dependence is characterized as a multi-factorial disorder caused by a complex interaction between genetic and environmental liabilities across development. A variety of neurocognitive deficits/dysfunctions involving impairments in different brain regions and/or neural circuitries have been associated with chronic alcoholism, as well as with a predisposition to develop alcoholism. Several neurobiological and neurobehavioral approaches and methods of analyses have been used to understand the nature of these neurocognitive impairments/deficits in alcoholism. In the present review, we have examined relatively novel methods of analyses of the brain signals that are collectively referred to as event-related oscillations (EROs) and show promise to further our understanding of human brain dynamics while performing various tasks. These new measures of dynamic brain processes have exquisite temporal resolution and allow the study of neural networks underlying responses to sensory and cognitive events, thus providing a closer link to the physiology underlying them. Here, we have reviewed EROs in the study of alcoholism, their usefulness in understanding dynamical brain functions/dysfunctions associated with alcoholism as well as their utility as effective endophenotypes to identify and understand genes associated with both brain oscillations and alcoholism.

Characterization of South African adolescents with alcohol use disorders but without psychiatric or polysubstance comorbidity

BACKGROUND

Individuals who begin drinking during early adolescence and exhibit externalizing pathology and disinhibitory/dysregulatory tendencies are more vulnerable to developing alcohol use disorders (AUDs) in adulthood. Previous research has focused on in-treatment populations with substantial comorbid psychopathology and polysubstance use. Here, we characterize a unique sample of treatment-naïve adolescents without such comorbidity to help identify vulnerable youth who may benefit from early intervention.

METHODS

We compared externalizing propensity, disinhibitory characteristics, and school performance in adolescents with AUDs (but without comorbid psychopathology or other substance use; n = 70) to those of demographically matched controls (n = 70). Within the AUD group, we compared measures of substance use and the disinhibitory syndrome between boys and girls with differing severity of externalizing propensity.

RESULTS

Adolescents with AUDs demonstrated more externalizing propensity and disinhibitory personality traits (impulsivity, novelty seeking, and excitement seeking), poorer self-monitoring and response inhibition, more bullying and sexual risk-taking behavior, poorer first-language performance, and greater use of alcohol, cannabis, and nicotine (p < 0.05). Within the AUD group, participants with higher externalizing propensity began drinking earlier, more frequently, and for a longer duration than those with lower externalizing symptoms (p < 0.05). Disinhibitory features (personality, cognition, and behavior) were, however, not stronger in those with higher externalizing propensity.

CONCLUSIONS

We suggest that the constructs of externalizing propensity and disinhibitory syndrome are useful in characterizing treatment-naïve adolescents with AUDs but without comorbid psychopathology or polysubstance use. These results support the importance of these constructs in understanding adolescent AUDs, even when the frank externalizing diagnoses of childhood (oppositional defiant disorder and conduct disorder) are excluded.

Cognitive functioning in opioid-dependent patients treated with buprenorphine, methadone, and other psychoactive medications: stability and correlates

BACKGROUND

In many but not in all neuropsychological studies buprenorphine-treated opioid-dependent patients have shown fewer cognitive deficits than patients treated with methadone. In order to examine if hypothesized cognitive advantage of buprenorphine in relation to methadone is seen in clinical patients we did a neuropsychological follow-up study in unselected sample of buprenorphine- vs. methadone-treated patients.

METHODS

In part I of the study fourteen buprenorphine-treated and 12 methadone-treated patients were tested by cognitive tests within two months (T1), 6-9 months (T2), and 12-17 months (T3) from the start of opioid substitution treatment. Fourteen healthy controls were examined at similar intervals. Benzodiazepine and other psychoactive comedications were common among the patients. Test results were analyzed with repeated measures analysis of variance and planned contrasts. In part II of the study the patient sample was extended to include 36 patients at T2 and T3. Correlations between cognitive functioning and medication, substance abuse, or demographic variables were then analyzed.

RESULTS

In part I methadone patients were inferior to healthy controls tests in all tests measuring attention, working memory, or verbal memory. Buprenorphine patients were inferior to healthy controls in the first working memory task, the Paced Auditory Serial Addition Task and verbal memory. In the second working memory task, the Letter-Number Sequencing, their performance improved between T2 and T3. In part II only group membership (buprenorphine vs. methadone) correlated significantly with attention performance and improvement in the Letter-Number Sequencing. High frequency of substance abuse in the past month was associated with poor performance in the Letter-Number Sequencing.

CONCLUSIONS

The results underline the differences between non-randomized and randomized studies comparing cognitive performance in opioid substitution treated patients (fewer deficits in buprenorphine patients vs. no difference between buprenorphine and methadone patients, respectively). Possible reasons for this are discussed.