The effects of dehydration, moderate alcohol consumption, and rehydration on cognitive functions

This study investigated the impact of mild–moderate dehydration on alcohol-induced deteriorations in cognitive functions. 

Sixteen healthy males participated in a single-blind, placebo-controlled cross-over design study involving 4 experimental trials (separated by ≥7 d). In each trial, participants were dehydrated by 2.5% body mass through exercise. After 1 h recovery in a thermo-neutral environment (22 ± 2 °C, 60–70% relative humidity) 4 tasks from the Cambridge Neuropsychological Test Automated Battery (CANTAB) were administered to the participants (test 1). In two of the trials, participants were provided with water equivalent to either 50% or 150% body mass loss and given salt (NaCl) capsules (50 mmol/L). A set volume of alcohol or placebo was then consumed in each trial, incorporating the conditions: dehydration-placebo (DP), dehydration-alcohol (DA), partial rehydration-alcohol (PA), and full rehydration-alcohol (FA). The same 4 CANTAB tasks were then re-administered (test 2). Subjective ratings of mood and estimates of alcohol intoxication and driving impairment were also recorded in each trial. 

Alcohol consumption caused deterioration on 3 of the 4 CANTAB measures (viz., choice reaction time, executive function and response inhibition). This reduction in performance was exacerbated when participants were dehydrated compared to trials where full rehydration occurred. 

Subjective ratings of impairment and intoxication were not significantly different between any of the trials where alcohol was consumed; however ratings for alcohol trials were significantly higher than in the placebo trial. 

These findings suggest that rehydration after exercise that causes fluid loss can attenuate alcohol-related deterioration of cognitive functions. This may pose implications for post match fluid replacement if a moderate amount of alcohol is also consumed.


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Request Reprint E-Mail:    irwin@griffith.edu.au

Substance Use Among Military-Connected Youth: The California Healthy Kids Survey

Young people in military-connected families may be exposed to deleterious stressors, related to family member deployment, that have been associated with externalizing behaviors such as substance use. Substance use predisposes youth to myriad health and social problems across the life span.

This study examined the prevalence and correlates of lifetime and recent substance use in a normative sample of youth who were either connected or not connected to the military.

Data are from a subsample of the 2011 California Healthy Kids Survey (N=14,149). Items in the present analyses included present familial military affiliation (no one, parent, sibling); number of deployments (none, one, two or more); gender; grade; and race/ethnicity. Substance use items assessed whether the youth reported lifetime use of alcohol, tobacco, marijuana, other drugs, or prescription drugs; and recent (past 30 days) use of alcohol, tobacco, marijuana, and other drugs.

Multivariate analysis conducted in 2012 revealed that an increase in the number of deployments was associated with a higher likelihood of lifetime and recent use, with the exception of lifetime smoking.

These results indicate that experiences associated with deployment of a family member may increase the likelihood of substance use.

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Request Reprint E-Mail:    tgilreat@usc.edu

Do parent--child acculturation gaps affect early adolescent Latino alcohol use? A study of the probability and extent of use

The literature has been mixed regarding how parent--child relationships are affected by the acculturation process and how this process relates to alcohol use among Latino youth. 

The mixed results may be due to, at least, two factors: First, staggered migration in which one or both parents arrive to the new country and then send for the children may lead to faster acculturation in parents than in children for some families. Second, acculturation may have different effects depending on which aspects of alcohol use are being examined. 

This study addresses the first factor by testing for a curvilinear trend in the acculturation-alcohol use relationship and the second by modeling past year alcohol use as a zero inflated negative binomial distribution.

Additionally, this study examined the unique and mediation effects of parent--child acculturation discrepancies (gap), mother involvement in children's schooling, father involvement in children's schooling, and effective parenting on youth alcohol use during the last 12 months, measured as the probability of using and the extent of use. Direct paths from parent--child acculturation discrepancy to alcohol use, and mediated paths through mother involvement, father involvement, and effective parenting were also tested.

Only father involvement fully mediated the path from parent--child acculturation discrepancies to the probability of alcohol use. None of the variables examined mediated the path from parent--child acculturation discrepancies to the extent of alcohol use.

Effective parenting was unrelated to acculturation discrepancies; however, it maintained a significant direct effect on the probability of youth alcohol use and the extent of use after controlling for mother and father involvement. Implications for prevention strategies are discussed.


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Effectiveness of a Selective, Personality-Targeted Prevention Program for Adolescent Alcohol Use and Misuse A Cluster Randomized Controlled Trial

                 
 Selective school-based alcohol prevention programs targeting youth with personality risk factors for addiction and mental health problems have been found to reduce substance use and misuse in those with elevated personality profiles.

To report 24-month outcomes of the Teacher-Delivered Personality-Targeted Interventions for Substance Misuse Trial (Adventure trial) in which school staff were trained to provide interventions to students with 1 of 4 high-risk (HR) profiles: anxiety sensitivity, hopelessness, impulsivity, and sensation seeking and to examine the indirect herd effects of this program on the broader low-risk (LR) population of students who were not selected for intervention.

Cluster randomized controlled trial.

Secondary schools in London, United Kingdom.

A total of 1210 HR and 1433 LR students in the ninth grade (mean [SD] age, 13.7 [0.33] years).

Schools were randomized to provide brief personality-targeted interventions to HR youth or treatment as usual (statutory drug education in class).

Participants were assessed for drinking, binge drinking, and problem drinking before randomization and at 6-monthly intervals for 2 years.

Two-part latent growth models indicated long-term effects of the intervention on drinking rates (β = −0.320, SE = 0.145, P = .03) and binge drinking rates (β = −0.400, SE = 0.179, P = .03) and growth in binge drinking (β = −0.716, SE = 0.274, P = .009) and problem drinking (β = −0.452, SE = 0.193, P = .02) for HR youth. The HR youth were also found to benefit from the interventions during the 24-month follow-up on drinking quantity (β = −0.098, SE = 0.047, P = .04), growth in drinking quantity (β = −0.176, SE = 0.073, P = .02), and growth in binge drinking frequency (β = −0.183, SE = 0.092, P = .047). Some herd effects in LR youth were observed, specifically on drinking rates (β = −0.259, SE = 0.132, P = .049) and growth of binge drinking (β = −0.244, SE = 0.073, P = .001), during the 24-month follow-up.

Findings further support the personality-targeted approach to alcohol prevention and its effectiveness when provided by trained school staff. Particularly novel are the findings of some mild herd effects that result from this selective prevention program.


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Request Reprint E-Mail:    patricia.conrod@kcl.ac.uk

Synergism Between Obesity and Alcohol in Increasing the Risk of Hepatocellular Carcinoma: A Prospective Cohort Study

Obesity and alcohol interact to increase the risk of death from liver failure in men. In the present study, we aimed to examine whether obesity and alcohol were multiplicative or additive in increasing the risk of hepatocellular carcinoma (HCC) in both men and women. 

We conducted a prospective, population-based study of 23,712 Taiwanese residents (50.3% men) from 7 townships who underwent an evaluation for liver disease and were followed for 11.6 years for incident HCC. The mean age was 47 (standard deviation, 10) years and the mean body mass index (weight (kg)/height (m)²) was 24 (standard deviation, 3). Overall, 305 cases of HCC were identified over 275,126 person-years of follow-up.

Age, male sex, alcohol drinking, cigarette smoking, elevated alanine aminotransferase, serum hepatitis B surface antigen, anti-hepatitis C virus positivity, and diabetes mellitus were each statistically significant predictors of incident HCC in univariate analyses (P < 0.05). 

Alcohol use and obesity (body mass index ≥30) showed a synergistic association with the risk of incident HCC in both unadjusted analyses (hazard ratio = 7.19, 95% confidence interval: 3.69, 14.00; P < 0.01) and multivariable-adjusted analyses (age, sex, smoking, serum alanine aminotransferase, serum hepatitis B surface antigen, anti-hepatitis C virus antibody, and diabetes mellitus) (hazard ratio = 3.82, 95% confidence interval: 1.94, 7.52; P < 0.01).

Relative excess risks due to interaction, attributable proportion, and synergy index were 4.83, 0.67, and 4.53, respectively, suggesting a multiplicative interaction between alcohol use and obesity. Obesity and alcohol synergistically increase the risk of incident HCC.


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Request Reprint E-Mail:    roloomba@ucsd.edu

Genetic and Environmental Predictors of Latent Trajectories of Alcohol Use from Adolescence to Adulthood: A Male Twin Study

Adolescence is characterized by higher levels of novelty-seeking and risk-taking behavior, including initiation of alcohol use. Also, there is considerable heterogeneity in the change and continuity of alcohol use over time, which emphasizes the need to examine factors predicting alcohol use and the patterns of use over time.

Retrospective data on average monthly alcohol use and risk and protective factors were obtained through interviews and questionnaires in 1,560 adult male twins. Latent class growth analysis in Mplus was performed on data of alcohol use over ages 15 to 36. Second, logistic regression analyses were used to associate risk and protective characteristics with membership in distinct latent trajectories of alcohol use.

Six trajectories of alcohol use were identified, varying in the level of alcohol use, the rate of change in use in early adolescence and the persistence of use into adulthood. Genetic risk of externalizing disorder and peer deviance showed the greatest risks for unfavorable alcohol trajectories with higher levels of use and higher rates of early increase in use. Parental monitoring and involvement in social activities showed protective effects. Involvement in religious activities was strongly associated with reduced persistence of high-level drinking in univariate but not multivariate regression analyses.

Risk and protective factors impacted differentially on level of alcohol use, rate of increase in use during adolescence, and persistence of heavy alcohol use over time. Insight into the different ways in which predictors impact on alcohol use is relevant for the development of new intervention strategies. For this purpose, causality of the associations should be further examined.


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Request Reprint E-Mail:   m.wichers@maastrichtuniversity.nl

The Persistent Effects of Minimum Legal Drinking Age Laws on Drinking Patterns Later in Life

Exposure to permissive minimum legal drinking age (MLDA) laws not only affects young adults in the short term, but also later in life; for example, individuals who could legally purchase alcohol before the age of 21 are more likely to suffer from drinking problems as older adults, long after the laws had been changed. However, it is not known how permissive MLDA exposure affects specific drinking behavior. This present study uses changes in MLDA laws during the 1970s and 1980s as a natural experiment to investigate the potential impact of permissive MLDA exposure on average alcohol consumption, frequency of drinking, and patterns of binging and more moderate, nonheavy drinking.

Policy exposure data were paired with alcohol use data from the 1991 to 1992 National Longitudinal Alcohol Epidemiologic Survey and the 2001 to 2002 National Epidemiologic Survey on Alcohol and Related Conditions. Past-year drinkers born between 1949 and 1972 (n = 24,088) were included. Average daily intake, overall drinking frequency, and frequency of both binge episodes (5+ drinks) and days without a binge episode (nonheavy drinking) for the previous year at the time of interview were tracked for each respondent.

Exposure to permissive MLDAs was associated with higher odds to report frequent binging and lower odds to report any moderate drinking; these associations were largely driven by men and those who did not attend college. Overall drinking frequency and average alcohol consumption were not affected by MLDA exposure.

The ability to legally purchase alcohol before the age of 21 does not seem to increase overall drinking frequency, but our findings suggest that it is associated with certain types of problematic drinking behaviors that persist into later adulthood: more frequent binge episodes and less frequent nonheavy drinking. We also propose that policymakers and critics should not focus on college drinking when evaluating the effectiveness of MLDAs.


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Request Reprint E-Mail:   plunka@psychiatry.wustl.edu

Assessment of a Modified DSM-5 Diagnosis of Alcohol Use Disorder in a Genetically Informative Population

Proposed changes to the upcoming DSM-5 include the following: (i) combining criteria for DSM-IV alcohol abuse (AA) and alcohol dependence (AD) into 1 diagnostic category (alcohol use disorder [AUD]); (ii) exclusion of the “legal problems” (LP) criterion; and (iii) addition of a “craving” criterion. Few published studies empirically assess the potential consequences of the proposed changes.

Using a population-based sample of twins assessed for lifetime AA/AD diagnoses, we explored phenotypic differences across DSM-IV and a modified DSM-5 diagnoses without craving because of its unavailability in the data set. We used factor analysis and item response theory (IRT) to evaluate the potential consequences of excluding the LP criterion from AUD and used twin modeling to examine genetic differences between DSM-IV and the modified DSM-5 diagnoses.

The prevalence of AUD was slightly higher than that of DSM-IV diagnoses. Individuals meeting DSM-IV or DSM-5 criteria, but not both, exhibit fewer comorbid diagnoses than those meeting both sets of criteria. Individuals meeting only DSM-5 criteria were slightly less severely affected than those meeting only DSM-IV criteria. Factor analysis indicated that the LP criterion loading is the lowest of all symptoms; IRT analysis suggested that this criterion has low discriminatory power. The genetic correlation between DSM-IV and DSM-5 diagnoses was slightly but significantly lower than unity.

The proposed DSM-5 AUD criteria are unlikely to result in significant changes in prevalence of diagnosed alcohol problems. However, it is unclear whether the new criteria represent a more valid diagnosis: new cases are no more severely affected than DSM-IV-only cases. Given the psychometric properties of LP, its exclusion should not negatively impact diagnostic validity. Similarly, the stable heritability across DSM-IV and DSM-5 diagnoses suggests that the proposed changes will not have substantial negative consequences in terms of familial influences, a key validator. These results provide equivocal empirical support for the proposed DSM-5 changes for AUDs.

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Request Reprint E-Mail:   aedwards5@vcu.edu

Binge Ethanol and Liver: New Molecular Developments

Binge consumption of alcohol is an alarming global health problem. Binge (acute) ethanol (EtOH) is implicated in the pathophysiology of alcoholic liver disease (ALD). New studies from experimental animals and from humans indicate that binge EtOH has profound effects on immunological, signaling, and epigenetic parameters of the liver. This is in addition to the known metabolic effects of acute EtOH. Binge EtOH alters the levels of several cellular components and dramatically amplifies liver injury in chronically EtOH exposed liver. 

These studies highlight the importance of molecular investigations into binge effects of EtOH for a better understanding of ALD and also to develop therapeutic strategies to control it. 

This review summarizes these recent developments.


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Request Reprint E-Mail:    ShuklaSD@health.missouri.edu

Determining the Threshold for Alcohol-Induced Brain Damage: New Evidence with Gliosis Markers

Chronic intake of ethanol (EtOH) has been linked to serious health consequences such as cardiac and liver problems, cognitive impairments, and brain damage. Alcohol's detrimental effects depend upon the dose, duration, and pattern of exposure with binge drinking as one of the most common, but most damaging, patterns of intake. Little is known about the threshold of the damaging effects of alcohol. Therefore, these experiments sought to determine a threshold for brain damage using various markers of neurodegeneration.

Adult male Sprague–Dawley rats were administered nutritionally complete liquid diet containing either EtOH (25% w/v) or isocaloric dextrose every 8 hours for either 1 (mean dose, 13.4 ± 0.3 g/kg/d; mean blood EtOH concentration (BEC), 336.2 ± 18.8 mg/dl) or 2 days (mean dose, 10.9 ± 0.3 g/kg/d; mean BEC, 369.8 ± 18.1 mg/dl). On the basis of a known time course of various neurodegeneration-associated events, rats were perfused transcardially immediately following, 2 days after, or 7 days post EtOH exposure. To label actively dividing cells, some animals were injected with BromodeoxyUridine (BrdU) 2 hours prior to perfusion. Tissue was then analyzed for the presence of BrdU (cell proliferation), FluoroJade B (degenerative neurons), and 
vimentin (reactive astrogliosis) immunoreactivity.

One or 2 days of EtOH exposure failed to alter cell proliferation at any of the time points analyzed. However, significant 2- to 9-fold increases in neuronal degeneration in limbic cortex and clear evidence of reactive gliosis as indicated by a 2- to 8-fold upregulation in vimentin immunoreactivity in the hippocampus were observed following as little as 1 day of binge EtOH exposure.

These results indicate that as little as 1 day (24 hours) of high BEC, binge-like EtOH exposure is enough to elicit signs of alcohol-induced brain damage in adult rats. Further, reactive gliosis may be a more sensitive marker of alcohol-induced damage in the hippocampus.


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Request Reprint E-Mail:  kim-nixon@uky.edu

Genotype modulates age-related alterations in sensitivity to the aversive effects of ethanol: an eight inbred strain analysis of conditioned taste aversion

Adolescent individuals display altered behavioral sensitivity to ethanol, which may contribute to the increased ethanol consumption seen in this age-group. However, genetics also exert considerable influence on both ethanol intake and sensitivity. Currently there is little research assessing the combined influence of developmental and genetic alcohol sensitivities. 

Sensitivity to the aversive effects of ethanol using a conditioned taste aversion (CTA) procedure was measured during both adolescence (P30) and adulthood (P75) in eight inbred mouse strains (C57BL/6J, DBA/2J, 129S1/SvImJ, A/J, BALB/cByJ, BTBR T⁺tf/J, C3H/HeJ and FVB/NJ). Adolescent and adult mice were water deprived, and subsequently provided with access to 0.9% (v/v) NaCl solution for 1 h. Immediately following access mice were administered ethanol (0, 1.5, 2.25 and 3 g/kg, ip). This procedure was repeated in 72 h intervals for a total of five CTA trials. 

Sensitivity to the aversive effects of ethanol was highly dependent upon both strain and age. Within an inbred strain, adolescent animals were consistently less sensitive to the aversive effects of ethanol than their adult counterparts. However, the dose of ethanol required to produce an aversion response differed as a function of both age and strain.


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Request Reprint E-Mail:  slboehm@iupui.edu

Early Subjective Response and Acquired Tolerance as Predictors of Alcohol Use and Related Problems in a Clinical Sample

Previous studies have demonstrated that a low subjective response (SR) to alcohol is a risk factor for alcohol use disorders (AUDs), and a recent study suggests that acquired tolerance can be differentiated from initial SR and is also significantly associated with drinking problems. Because the prior study of SR and tolerance focused on a sample of moderate drinkers, the goal of the current study was to examine relations between early SR, acquired tolerance, alcohol use, and alcohol-related problems in a sample of young adults with clinically significant alcohol problems.\

The current study examined associations between early SR and acquired tolerance and both drinking behavior and alcohol-related problems within a sample of 113 heavy drinking young adults (66.1% male) volunteering for a clinical trial of naltrexone in combination with brief motivational counseling.

Consistent with the 1 prior study examining simultaneous effects of early SR and tolerance, both early SR and acquired tolerance were positively associated with typical drinking behavior, although tolerance was a much stronger predictor within this clinical sample. In contrast to the prior study, early SR was inversely associated with risk for alcohol-related problems, and tolerance was not a significant predictor of problems.

The results suggested that, controlling for weekly drinking, a low early SR protected against acute negative consequences within a sample of heavy drinkers who had acquired significant tolerance to alcohol effects. It is possible that this protective effect may eventually shift to a risk factor by allowing individuals with a low SR to persist in a pattern of hazardous drinking.


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Request Reprint E-Mail:  wcorbin@asu.edu

Alcohol and Sleep I: Effects on Normal Sleep

This review provides a qualitative assessment of all known scientific studies on the impact of alcohol ingestion on nocturnal sleep in healthy volunteer's. 

At all dosages, alcohol causes a reduction in sleep onset latency, a more consolidated first half sleep and an increase in sleep disruption in the second half of sleep. The effects on rapid eye movement (REM) sleep in the first half of sleep appear to be dose related with low and moderate doses showing no clear trend on REM sleep in the first half of the night whereas at high doses, REM sleep reduction in the first part of sleep is significant. Total night REM sleep percentage is decreased in the majority of studies at moderate and high doses with no clear trend apparent at low doses. The onset of the first REM sleep period is significantly delayed at all doses and appears to be the most recognizable effect of alcohol on REM sleep followed by the reduction in total night REM sleep.

The majority of studies, across dose, age and gender, confirm an increase in slow wave sleep (SWS) in the first half of the night relative to baseline values. The impact of alcohol on SWS in the first half of night appears to be more robust than the effect on REM sleep and does not appear to be an epiphenomenon REM sleep reduction. Total night SWS is increased at high alcohol doses across gender and age groups.


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Request Reprint E-Mail:     info@londonsleepcentre.com

Do alcohol use disorders destabilize the course of bipolar disorder?

To determine whether long-term data implicate a negative effect of alcohol-use disorders (AUDs) on time to remission, risk of mood episode recurrence, and risk of mood switch/cycling in patients with bipolar disorder (BD). The short-term temporal sequence between alcohol use and onset of mood episodes was also examined.

A MEDLINE literature search was conducted for measurement-based reports of alcohol and course of bipolar disorder.

Twenty-three original data publications were identified. Three out of 5 studies addressing the impact of AUDs on recovery from a mood episode demonstrated that alcohol did not prolong index mood episodes of any type. Six out of 11 reports evaluating the relationship between alcohol and the long term risk of mood episode recurrences suggested that high levels of alcohol intake increase the risk of a mood recurrence. Five out of 7 studies evaluating the short-term temporal sequence of AUDs and development of mood episodes among BD patients found that increased alcohol use preceded the development of new mood episodes. Four out of 5 studies examining the association between alcohol and rapid cycling indicated that AUDs were associated with higher rates of rapid-cycling.

We limited our review to studies that were large enough to perform statistical testing, which may have led us to overlook informative smaller studies.

Although alcohol does not seem to affect time to mood episode remission, alcohol use destabilizes the course of illness over the long run as evidenced by associations with more rapid cycling and mood episode recurrence.


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Request Reprint E-Mail:  Jrakofs@emory.edu

Reducing the alcohol and drug toll: Victoria's plan 2013 - 2017

The Minister for Mental Health, the Hon. Mary Wooldridge has released Reducing the alcohol and drug toll. Victoria’s plan 2013 – 2017. This is Victoria’s first whole of government strategy to reduce the impact of alcohol and drug abuse on the Victorian community.

The plan sets out how the Victorian Government will work with the community to bring down the alcohol and drug toll and deliver better health outcomes to thousands of Victorians who want to recover from the harm associated with alcohol misuse and drug use.

The Victorian Government is working to reduce the rates of risky drinking and drug use, and the toll of deaths, disease, injury, crime and other social costs from the misuse of alcohol and drugs.

Reducing the alcohol and drug toll sets out a 15-point plan that provides a comprehensive response to the three major drug types, alcohol, pharmaceutical drugs and illegal drugs. It also focuses on care, treatment and recovery as well as strengthening leadership and coordinated action in reducing the alcohol and drug toll.  > > > >  Read More

'Alcohol problems in the criminal justice system' WHO guidance released

The World Health Organization (WHO) have released a document outlining the scale of the link between alcohol and offending, and the missed opportunities to address alcohol misuse within the Criminal Justice System and prisons in particular.

Download 'Alcohol problems in the criminal justice system: an opportunity for
intervention' [pdf]

The document describes an integrated model of care for alcohol problems in prisoners, with elements for best practice. The model starts with assessment of prisoners’ alcohol problems, using a validated screening tool, the WHO Alcohol Use Disorders Identification Test (AUDIT), and calls for interventions tailored to prisoners’ specific needs.  > > > >  Read More

A spontaneous deletion of α-synuclein is associated with an increase in CB1 mRNA transcript and receptor expression in the hippocampus and amygdala: Effects on alcohol consumption

α-Synuclein (α-syn) protein and endocannabinoid CB1 receptors are primarily located in presynaptic terminals. An association between α-syn and CB1 receptors has recently been established in Parkinson's disease, but it is completely unknown whether there is an association between these two proteins in alcohol addiction. 

Therefore, we aimed to examine the α-syn mRNA transcript and protein expression levels in the prefrontal cortex, striatum, amygdala and hippocampus. These brain regions are the most frequently implicated in alcohol and other drug addiction.

In these studies, we used C57BL/6 mice carrying a spontaneous deletion of the α-syn gene (C57BL/6^Snca-/-) and their respective controls (C57BL/6^Snca+/+). These animals were monitored for spontaneous alcohol consumption (3-10%) and their response to a hypnotic-sedative dose of alcohol (3 g/kg) was also assessed. 

Compared with the C57BL/6^Snca+/+ mice, we found that the C57BL/6^Snca-/- mice exhibited a higher expression level of the CB1 mRNA transcript and CB1 receptor in the hippocampus and amygdala. 

Furthermore, C57BL/6^Snca-/- mice showed an increase in alcohol consumption when offered a 10% alcohol solution. There was no significant difference in sleep time after the injection of 3 g/kg alcohol. 

These results are the first to reveal an association between α-syn and the CB1 receptor in the brain regions that are most frequently implicated in alcohol and other drug addictions.


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Request Reprint E-Mail:   jalopezm@psi.ucm.es

Social Deprivation Enhances VTA Synaptic Plasticity and Drug-Induced Contextual Learning

Drug addiction is driven, in part, by powerful drug-related memories. Deficits in social life, particularly during adolescence, increase addiction vulnerability. Social isolation in rodents has been used extensively to model the effects of deficient social experience, yet its impact on learning and memory processes underlying addiction remains elusive. 

Here, we show that social isolation of rats during a critical period of adolescence (postnatal days 2142) enhances long-term potentiation of NMDA receptor (NMDAR)-mediated glutamatergic transmission in the ventral tegmental area (VTA). This enhancement, which is caused by an increase in metabotropic glutamate receptor-dependent Ca²⁺ signaling, cannot be reversed by subsequent resocialization.

Notably, memories of amphetamine- and ethanol-paired contextual stimuli are acquired faster and, once acquired, amphetamine-associated contextual memory is more resistant to extinction in socially isolated rats. 

We propose that NMDAR plasticity in the VTA may represent a neural substrate by which early life deficits in social experience increase addiction vulnerability.


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Request Reprint E-Mail:  morikawa@utexas.edu

Adjusting for unrecorded consumption in survey and per capita sales data: Quantification of impact on gender- and age-specific alcohol-attributable fractions for oral and pharyngeal cancers in Great Britain

Large discrepancies are typically found between per capita alcohol consumption estimated via survey data compared with sales, excise or production figures. This may lead to significant inaccuracies when calculating levels of alcohol-attributable harms. Using British data, we demonstrate an approach to adjusting survey data to give more accurate estimates of per capita alcohol consumption. 

First, sales and survey data are adjusted to account for potential biases (e.g. self-pouring, under-sampled populations) using evidence from external data sources. Secondly, survey and sales data are aligned using different implementations of Rehm et al.'s method [in (2010) Statistical modeling of volume of alcohol exposure for epidemiological studies of population health: the US example. Pop Health Metrics 8, 1–12]. Thirdly, the impact of our approaches is tested by using our revised survey dataset to calculate alcohol-attributable fractions (AAFs) for oral and pharyngeal cancers.

British sales data under-estimate per capita consumption by 8%, primarily due to illicit alcohol. Adjustments to survey data increase per capita consumption estimates by 35%, primarily due to under-sampling of dependent drinkers and under-estimation of home-poured spirits volumes. Before aligning sales and survey data, the revised survey estimate remains 22% lower than the revised sales estimate. Revised AAFs for oral and pharyngeal cancers are substantially larger with our preferred method for aligning data sources, yielding increases in an AAF from the original survey dataset of 0.47–0.60 (males) and 0.28–0.35 (females).

It is possible to use external data sources to adjust survey data to reduce the under-estimation of alcohol consumption and then account for residual under-estimation using a statistical calibration technique. These revisions lead to markedly higher estimated levels of alcohol-attributable harm.


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Request Reprint E-Mail:  john.holmes@sheffield.ac.uk

Global alcohol exposure estimates by country, territory and region for 2005 – a contribution to the Comparative Risk Assessment for the 2010 Global Burden of Disease Study

This study aimed to estimate the prevalence of lifetime abstainers, former drinkers and current drinkers, adult per capita consumption of alcohol, and pattern of drinking scores, by country and Global Burden of Disease region for 2005, and to forecast these indicators for 2010.

Statistical modelling based on survey data and routine statistics.

241 countries and territories.

Per capita consumption data were obtained with the help of the World Health Organization's Global Information System on Alcohol and Health. Drinking status data were obtained from Gender, alcohol and culture: an international study, the STEPwise approach to Surveillance study, the World Health Survey/Multi Country Study, and other surveys. Consumption and drinking status data were triangulated to estimate alcohol consumption across multiple categories.

Finding In 2005 adult per capita annual consumption of alcohol was 6.1 litres (l), with 28.8% stemming from unrecorded consumption. 17.1 l of alcohol were consumed per drinker, 45.8% of all adults were lifetime abstainers, 13.6% were former drinkers and 40.6% were current drinkers. Lifetime abstention was most prevalent in North Africa/ Middle East and South Asia. Eastern Europe and Southern Sub-Saharan Africa had the most detrimental pattern of drinking scores, while drinkers in Europe (Eastern and Central) and Sub-Saharan Africa (Southern and West) consumed the most alcohol.

Just over 40% of the world's adult population consumes alcohol and the average consumption per drinker is 17.1 litres per year. However, the prevalence of abstention, level of alcohol consumption and patterns of drinking vary widely across regions of the world.



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Request Reprint E-Mail:  Kevin.Shield@utoronto.ca