The influence of blood alcohol concentrations of around 0.03% on neuropsychological functions--a double-blind, placebo-controlled investigation

The impact of alcohol intoxication on extended vigilance and rest-break recovery

Alcohol has complex and multifarious effects on cognition. One means by which alcohol can influence a wide variety of cognitive behaviors is through its effects on attention. This study investigated the effects of alcohol consumption on sustained attention, or vigilance. We report here a high-powered study in which participants consumed either an alcoholic or a non-alcoholic beverage and then completed a spatial vigilance task, with half of the subjects in each condition receiving two rest breaks interleaved throughout the task. Alcohol impaired vigilance performance and also decreased the local recuperative benefit of rest breaks. Difference in decision processes were apparent, with intoxicated participants employing a more liberal and less optimal response criterion. These findings underscore the detrimental effects of alcohol on attention and provide novel evidence that rest is less effective following alcohol consumption.

Forensic Assessment of Alcohol Intoxication in Cases of Fatal Road Traffic Accidents in Lithuania

Background

There is strong evidence that alcohol consumption is a significant risk factor for fatal road traffic accidents. It is estimated that the number of alcohol-related road accidents remains high in the past few years in Lithuania. This study aims to examine the prevalence of alcohol in blood samples collected from the autopsy results of road traffic accident victims.

Materials and methods

A retrospective study of 136 road traffic accident victims was performed in State Forensic Medicine Service of Lithuania in the period of 2013 to 2023. We analyzed blood alcohol concentration (BAC) in relation to sex, age, road user type, place and time of the day at death.

Results

31% of the victims were under influence of alcohol at the time of death, with mean BAC 1.99 ± 0.92‰. The mean BAC was 2.16 ± 0.8‰ in male and 1.18 ± 1.12‰ in female group. By the type of road users, 23% of the pedestrians (mean BAC 2.45 ± 0.71‰), 32% of car drivers (mean BAC 2.13 ± 0.75‰), 41% of vehicle passengers (mean BAC of 1.73 ± 1.19‰), 37% of the motorcycle riders (mean BAC of 1.28 ± 0.53‰), 37% of the cyclists (mean BAC of 1.15 ± 0.75‰) were found to be intoxicated during the time of accident. Highest mean blood alcohol concentration was found during the night time hours (9 p. m. - 5 a. m.) 2.28 ± 0.91, comparing to in afternoon hours (12 p. m. - 5 p. m.) 1.49 ± 0.99, evening hours (5 p. m. - 9 p. m.) 2.10 ± 0.73 and morning hours (5 a. m. - 12 p. m.) 1.94 ± 1.00. The mean BAC in road traffic accidents during summer was 1.48 ± 0.71‰, spring 2.25 ± 0.76‰, autumn 2.12 ± 1‰, winter 2.42 ± 1‰.

Conclusions

Alcohol consumption by road users is a significant contributing factor in road traffic accidents and their outcomes in Lithuania.

Acute administration of alprazolam, alcohol and their combination on cognitive performance and mood: A randomised, double-blind, placebo-controlled study

BACKGROUND

Recreational co-consumption of benzodiazepines and alcohol is a common practise; yet, the cognitive effects of this combination remain poorly understood. This study aimed to investigate the acute cognitive effects of combining a 1 mg dose of alprazolam with a moderate dose of alcohol (target 0.04% blood alcohol concentration (BAC)) in a non-clinical population.

METHODS

In this randomised, double-blind, placebo-controlled, crossover trial, participants completed computerised cognitive assessments and the brief biphasic alcohol effects scale (B-BAES) after consuming 1 mg of alprazolam, both with and without a moderate dose of alcohol (target 0.04% BAC).

RESULTS

Among 20 healthy participants (mean age = 28.6, SD ± 4.0 years, 60% female), we found that a peak BAC of 0.03% had no significant impact on cognitive performance. Both the individual use of alprazolam and its combination with alcohol resulted in impaired reaction time, digit vigilance, and verbal, spatial and numeric working memory tasks, although an additive effect when alcohol and alprazolam were consumed together was not evident. The most pronounced cognitive effects occurred at 100 min after dosing, coinciding with increased alprazolam concentrations. Sedative effects were heightened with alcohol, alprazolam and their combination while no stimulative effects were reported.

CONCLUSIONS

Our findings highlight the significant implications of a therapeutic dose of alprazolam on impairing cognitive performance. This is particularly relevant considering the frequency of non-medical alprazolam use. Future studies should explore different dosages, administration timings and long-term effects to inform the development of public health policies and guidelines regarding the combined use of alcohol and benzodiazepines.

Sex differences in ethanol consumption and drinking despite negative consequences following adolescent social isolation stress in male and female rats

Alcohol use disorder (AUD) is a debilitating psychiatric disorder characterized by drinking despite negative social and biological consequences. AUDs make up 71% of substance use disorders, with relapse rates as high as 80%. Current treatments stem from data conducted largely in males and fail to target the psychological distress motivating drinking in stress-vulnerable and at-risk populations. Here we employed a rat model and hypothesized that early life stress would reveal sex differences in ethanol intake and drinking despite negative consequences in adulthood. Rats were group housed or isolated postweaning to evaluate sex and stress effects on ethanol consumption in homecage drinking, self-administration (SA), and punished SA (drinking despite negative consequences) in adulthood. Stressed rats showed elevated homecage ethanol intake, an effect more pronounced in females. During SA, males were more sensitive to stress-induced elevations of drinking over time, but females drank more overall. Stressed rats, regardless of sex, responded more for ethanol than their non-stressed counterparts. Stressed females showed greater resistance to punishment-suppressed SA than stressed males, indicating a more stress-resistant drinking phenotype. Results support our hypothesis that adolescent social isolation stress enhances adult ethanol intake in a sex- and model-dependent manner with females being especially sensitive to early life stress-induced elevations in ethanol intake and punished SA in adulthood. Our findings echo the clinical literature which indicates that stress-vulnerable populations are more likely to 'self-medicate' with substances. Elucidating a potential mechanism that underlies why vulnerable populations 'self-medicate' with alcohol can lead towards developing catered pharmacotherapeutics that could reduce punishment-resistant drinking and relapse.

Effects of alcohol intoxication on driving performance, confidence in driving ability, and psychomotor function: a randomized, double-blind, placebo-controlled study

RATIONALE

Alcohol-induced driving impairment can occur with any departure from a zero-blood alcohol concentration (BAC). Because intoxication is characterised by impaired judgement, drivers under the influence of alcohol may overestimate their capacity to safely operate a vehicle.

OBJECTIVES

This study examined the effects of alcohol on driving performance, four-choice reaction time (FCRT), and self-rated confidence in driving ability. It specifically focused on alcohol doses equal to commonly enforced legal BAC limits (i.e. 0.05% and 0.08%).

METHODS

A randomized, double-blind, placebo-controlled design was utilised. Seventeen participants were tested in three conditions: placebo and two alcohol conditions aiming for BACs of 0.05% and 0.08%. Participants underwent a baseline FCRT task and a 1-h simulated highway driving task before completing another FCRT task and rated their confidence in their driving ability.

RESULTS

The high and low alcohol dose conditions resulted in a mean BAC of 0.07%, and 0.04%, respectively (n = 17). The high BAC treatment significantly increased standard deviation of lateral position (SDLP) by 4.06 ± 5.21 cm and standard deviation of speed (SDS) by 0.69 ± 0.17 km/h relative to placebo, while confidence in driving ability remained unchanged across treatments. FCRT performance was impaired by the high BAC treatment (all < 0.01), but there we no significant differences between placebo and low BAC conditions.

CONCLUSIONS

The findings of this study show that driving performance and associated psychomotor functioning become significantly impaired below legally permissible driving limits in some jurisdictions. We identified a dissociation between driving performance and subjective awareness of impairment. Despite a significantly diminished driving ability at 0.07% BAC, drivers were unaware of their impairment.

None for the Road? Stricter Drink Driving Laws and Road Accidents

Reducing drink drive limits is generally regarded an effective strategy to save lives on the road. Using several new administrative data sources, we evaluate the effect of a stricter limit introduced in Scotland in 2014. This reduction had no effect on drink driving and road collisions. Estimates from a supply-of-offenses function suggests that the reform did not have much ex-ante scope for sizeable effects. The unavailability of cheaper alternative means of transportation and weak law enforcement seem to have been the main channels behind the lack of an impact. We find no externality on a wide range of domains, from alcohol consumption to criminal activities other than drink driving.

The effects of alcohol intoxication on cognitive functions critical for driving: A systematic review

Alcohol is the most frequently detected substance in drivers involved in road traffic collisions. Given that up to 35% of fatal road collisions are alcohol-related, it is important to determine the influence of alcohol intoxication on driving-related skills. This review provides an updated and systematic evaluation of the available research concerning the effect of alcohol intoxication on cognitive functions critical for driving. Databases EBSCOhost, PsycInfo, PubMed, Scopus, Transport Research International Documentation (TRID) and Web of Science were searched for controlled trials examining the effect of alcohol on divided attention, executive functioning, perception, psychomotor skills, reaction time and/or vigilance. Fourteen studies met the inclusion criteria and were included in this review. We found that each of the cognitive domains assessed in this review showed impairment at blood alcohol concentrations equal to or below the legal driving limit in many jurisdictions. Future research could determine the effects of alcohol on cognitive functioning with greater accuracy by employing more consistent, reliable and comparable measures while considering the translation of deficits to real-life driving.

Effect of alcohol on the sense of agency in healthy humans

Even at low to moderate doses, ingestion of the widely used recreational drug alcohol (ethanol) can impact cognitive and emotional processing. Recent studies show that the sense of agency (SoA; ie, the subjective experience of voluntary control over actions) can be modulated by specific pharmacological manipulations. The SoA, as quantified by the intentional binding (IB) paradigm, is enhanced by direct or indirect dopaminergic agonists in patients with Parkinson's disease and by ketamine (an N-methyl-D-aspartate (NMDA) receptor antagonist) in healthy individuals. These findings implicate dopaminergic and glutamatergic neurotransmission in mechanisms underlying SoA. Alcohol has a complex set of actions, including disinhibition of dopaminergic neurotransmission and allosteric antagonism at NMDA receptors. Here, we tested the hypothesis that low to moderate doses of alcohol would enhance SoA, and impact impulsivity and subjective emotional state. We conducted two experiments in 59 healthy male and female social drinkers, who ingested either a placebo "vehicle," or one of two doses of ethanol: 0.4 and 0.6 g/kg. In both experiments, we observed increased SoA/IB at both doses of alcohol exposure, relative to the placebo condition. We found no correlation between the effects of alcohol on IB and on impulsivity or subjective emotional state. Our findings might have implications for social and legal responsibility related to alcohol use, particularly in states prior to overt intoxication. Further studies are necessary to investigate the effects of alcohol and other addictive substances on the SoA.

Factors related to the quality of life in liver cancer patients during treatment phase: A follow-up study

OBJECTIVE

This study aims to explore the predictive value of demographic and clinical factors in changes in quality of life (QoL) in liver cancer (LC) patients over time.

METHODS

We performed a prospective cohort study in 128 patients who had 4 time point data newly diagnosed with LC at two hospitals in Taiwan. Different functional QoL was measured by QLQ-C30. Specific characteristics were predictors for distinct functional QoL, estimated by a generalised estimating equation (GEE).

RESULTS

Patients who received liver resection or radiofrequency ablation therapy (RFA) versus transarterial chemoembolisation (TACE) or transcatheter arterial embolisation (TAE) experienced a decrease in physical function from baseline to 1 month. In addition, patients who underwent liver resection versus RFA experienced a significant recovery in cognitive functioning from baseline to 6 months. Patients with advanced stage compared to those in early stage had a reduction in physical functioning from baseline to 1 month. The alcohol intake, hepatitis C infection and the job also affected the changes in physical and cognitive functioning.

CONCLUSION

Healthcare professionals should pay attention to changes after treatment in the short term; additionally, they need to provide health education to modifiable factors such as alcohol intake attributed to the deterioration in QoL.

Health risk assessment for pediatric population associated with ethanol and selected residual solvents in herbal based products

In this study, 48 herbal based products (41 for the pediatric population) were analyzed for the presence of ethanol and residual solvents. Ethanol was not detected in only 12% of the products designed for infants or toddlers aged under 2, and not quantified in only 5 of 14 'alcohol free' products. Actual content was higher than labeled in six out of 11 samples with specified ethanol quantity. WHO proposed requirement for ethanol content in products intended for use in children under the age of 6 (<0.5%) was not met by as many as 26 samples. Furthermore, calculated blood alcohol levels in children exceeded the relevant toxicological levels for nine samples following a single dose, and for one sample in case of accidental poisoning with the entire package. Regarding the residual solvents, acetone, 1-propanol and 1-butanol were not quantified, 2-propanol was found in two samples in low concentrations, whereas methanol intake via one of the samples exceeded the permitted level for children. The obtained results revealed a significant health concern for the pediatric population due to ethanol intake via herbal based products, calling for the establishment of strict guidelines for ethanol content and labeling.

Effects of Consuming a Low Dose of Alcohol with Mixers Containing Carbohydrate or Artificial Sweetener on Simulated Driving Performance

The Australian National Drug and Alcohol Research Centre (NDARC) devised gender-based drinking recommendations to ensure blood or equivalized breath alcohol concentrations (BrAC) remain <0.050%. However, these may be inappropriate for individuals consuming alcohol without carbohydrate (CHO), which results in higher BrACs. This study investigated the effects of ingesting alcohol with and without CHO on BrACs and simulated driving performance. Thirty-two participants (16 males; age: 23 ± 6 years) completed two randomized single-blinded trials. Participants performed a baseline drive (Drive 1), then an experimental drive (Drive 2), following alcohol consumption (males: 20 g; females: 10 g). Alcoholic beverages contained either 25 g sucrose or aspartame (AS). Driving performance was assessed using lateral control (standard deviation of lane position [SDLP] and number of lane departures) and risk-taking (number of overtaking maneuvers and maximum overtaking speed). BrAC and subjective ratings (e.g., intoxication) were also assessed. BrAC was significantly lower as Drive 2 commenced with CHO compared to AS (0.022 ± 0.008% vs. 0.030 ± 0.011%). Two males provided BrACs >0.050% with AS. Neither beverage influenced changes to simulated driving performance. Ingesting alcohol in quantities advised by the NDARC results in no detectable simulated driving impairment. However, the likelihood of exceeding the legal drink-driving BrAC is increased when alcohol is consumed with artificially-sweetened mixers.

Restricting access to alcohol and public health: Evidence from electoral dry laws in Brazil

We analyze the impact of short-term alcohol bans on road traffic accidents, traffic injuries, and hospital admissions. We focus on the 2012 Municipal Elections in Brazil, during which 11 out of 27 states imposed on its 2,733 municipalities the decision to adopt alcohol bans. Using day-level data on municipalities, we find that alcohol bans caused substantial reductions in road crashes (19%), traffic injuries (43%), and traffic-related hospitalizations (17%). An analysis of traffic-related hospitalization costs allows us to estimate the lower bound of the negative externality associated with excessive alcohol consumption in this context, which reveals that electoral dry laws saved Brazil's public healthcare system $100,000 per day.

Effects of acute alcohol ingestion on eye movements and cognition: A double-blind, placebo-controlled study

Alcohol is one of the most consumed psychoactive substances in the world, and the negative impact related to alcohol use has become a worldwide public health issue. Alcohol is able to affect diffusely several areas of the Central Nervous System, which could impair visual functions, including eye movements, and cognitive processes. The objective of the present study was to investigate the effects of moderate alcohol intake in eyes movements, as an indicator of cognitive processing underlying the visual search in a the Maze task. We investigated the concentration of 0.08% blood alcohol concentration (BAC), using an intra-subject, double-blind, and placebo-controlled experimental design with a sample size of 20 young adults (11 men and nine women). All volunteers participated in both conditions, i.e., alcohol (0.08%) and placebo (0.00%), in a counterbalanced order. We use the Tobii TX300 eye tracker to evaluate eye movements during completion of Visual Maze Test. The results showed significant differences in the following eye movement patterns: the first fixation latency, number and duration of fixations (mean and total), the number and duration of saccades (mean and total), and the total execution time in the test. In addition, we investigate the areas of interest (AOI), decision points in which the participant must decide which course to follow. We verified that the participants in the alcohol condition had a significantly greater number of fixations in both AOI, in comparison to the placebo condition. Overall, our findings confirm that moderate doses of alcohol can change the eye movements of young adults. These alterations may evidence the influence of alcohol in cognitive processes, such as flexibility, attention, and planning, which are required during resolution of Maze Task.

Acute Effects of Moderate Alcohol Consumption on Postural Stability in Older Adults

This study involved healthy community-living older adults in an investigation of the association between moderate alcohol consumption (AC) and acute changes in postural stability and whether the association differed according to pre-AC balance skills. Thirty-nine moderate drinkers aged ≥ 65 years (62% women; mean age: 73.9 ± 6.1 years) consumed a moderate dose of alcohol (0.4 g/kg; administered as two drinks). Breath alcohol concentration and postural stability were measured at five time points (pre-AC and 40, 80, 120, and 160 minutes post-AC) using unipedal stance time (UPST) and center of pressure (CoP) displacement. Pre-AC UPST was used to categorize participants into good-balance (≥30 seconds) and poor-balance (<30 seconds) groups. Peak breath alcohol concentration was 30 mg/dL at 40 minutes post-AC. For all participants, postural stability declined significantly at 80 minutes post-AC (UPST, p = .005; anterior–posterior CoP displacement, p = .029). While the poor-balance group did not show a significant decrease in UPST duration over the course of the study, the good-balance group experienced significant decline at 80 minutes compared with baseline ( p < .001) and remained above the 30-second UPST cutoff. Both groups experienced similar worsening in anterior–posterior CoP displacement at 80 minutes post-AC. Thus, moderate AC was associated with acute decline in postural stability in older adults. The worsened anterior–posterior CoP displacement post-AC in the poor-balance group was of particular concern because these participants were already at lower balance functioning pre-AC. Larger, more representative studies of varying groups of participants are needed to further explore how this change relates to fall incidents and fall risk.

Titrating Tipsy Targets: The Neurobiology of Low-Dose Alcohol

Limited attention has been given to our understanding of how the brain responds to low-dose alcohol (ethanol) and what molecular and cellular targets mediate these effects. Even at concentrations lower than 10mM (0.046 g% blood alcohol concentration, BAC), below the legal driving limit in the USA (BAC 0.08 g%), alcohol impacts brain function and behavior. Understanding what molecular and cellular targets mediate the initial effects of alcohol and subsequent neuroplasticity could provide a better understanding of vulnerability or resilience to developing alcohol use disorders. We review here what is known about the neurobiology of low-dose alcohol, provide insights into potential molecular targets, and discuss future directions and challenges in further defining targets of low-dose alcohol at the molecular, cellular, and circuitry levels.

Influence of alcohol use on mortality and expenditure during hospital admission: a cross-sectional study

OBJECTIVES

This study was designed to investigate the effect of alcohol intoxication on clinical presentation of hospitalised adult trauma patients at a Level I trauma centre using propensity score matching.

DESIGN

Cross-sectional study.

SETTING

Taiwan.

PARTICIPANTS

Detailed data of 929 hospitalised adult trauma patients with alcohol intoxication, aged 20-65 years, and 10 104 corresponding patients without alcohol intoxication were retrieved from the Trauma Registry System between 1 January 2009 and 31 December 2014. Alcohol intoxication was defined as a blood alcohol concentration (BAC) ≥50 mg/dL.

MAIN OUTCOME MEASURES

In-hospital mortality and expenditure.

RESULTS

Patients with alcohol intoxication presented with significantly higher short-term mortality (OR: 3.0, 95% CI 2.0 to 4.4; p<0.001) than patients without alcohol intoxication. However, on comparison with propensity score-matched patients with respect to sex, age, comorbidity, Glasgow Coma Scale (GCS), injury region based on Abbreviated Injury Scale (AIS) and Injury Severity Score (ISS), alcohol intoxication did not significantly influence mortality (OR: 0.8, 95% CI 0.5 to 1.4; p=0.563). This implied that the higher mortality of alcohol-intoxicated patients was attributable to patient characteristics such as a higher injury severity rather than alcohol intoxication. Even on comparison with sex-matched, age-matched and comorbidity-matched patients without alcohol intoxication, patients with alcohol intoxication still had significantly higher total expenditure (17.4% higher), cost of operation (40.3% higher), cost of examination (52.8% higher) and cost of pharmaceuticals (38.3% higher).

CONCLUSIONS

The associated higher mortality of adult trauma patients with alcohol intoxication was completely attributable to other patient characteristics and associated injury severity rather than the effects of alcohol. However, patients with alcohol intoxication incurred significantly higher expenditure than patients without alcohol intoxication, even on comparison with sex-matched, age-matched and comorbidity-matched patients without alcohol intoxication.

Blood alcohol concentration in fatally injured drivers and the efficacy of alcohol policies of the new law on road traffic safety: A retrospective 10-year study in autonomous province of Vojvodina, Republic of Serbia

OBJECTIVE

The aim of this study was primarily to evaluate inebriated fatally injured drivers (FIDs) according to blood alcohol concentration (BAC) in a 10-year period (2004-2013) in Autonomous Province (AP) of Vojvodina, Republic of Serbia, to analyze the efficacy of alcohol polices in the new law on road traffic safety through changes in the number of inebriated FIDs before and after implementation of the law, as well as to identify factors that influence the occurrence of FIDs with BACs above the legal limit.

METHODS

All data for this retrospective study were obtained from the Centre of Forensic Medicine, Toxicology and Molecular Genetics of Clinical Centre of Vojvodina, Novi Sad. Autopsy records for each case included age, gender, BAC, type of vehicle, and date of accident (year, month, and recalculated day of the week). BAC was determined by gas chromatography with flame ionization detection. Statistical analysis was carried out by chi-square tests and Student's t test, with P < .05 as a statistical significance, and multiple binary logistic regression.

RESULTS

Of the 354 inebriated FIDs (60% of all FIDs), the majority had BACs between of 0.031 and 0.3 mg/ml (28%), followed by those with BAC > 2.01 mg/ml (23%). The average BAC of those driving under the influence of alcohol (DUIA) for the whole period was 1.235 ± 1.00 mg/ml and the average number of DUIA/year was 35. Among the total number of FIDs there were significantly more males (93.7%; P < .001) than females (6.3%), though the distribution of intoxicated men and women was not different (P > .05). There was a statistically significant difference in the distribution of sober and inebriated FIDs according to age (P < .001) with the predominance of inebriated FIDs between 21 and 30 years. Although gender and age were found to be significant predictors of BAC above legal limit in FIDs, the area under the receiver operating characteristics (ROC) curve showed that the model had poor discrimination (ROC = 0.673). Of all observed FIDs, 65 cases per year were attributed to the first 5-year period (2004-2009) and 49 to the second 5-year (2010-2013) period, which indicates that there was no statistically significant decrease in the number of FIDs after implementation of the new law.

CONCLUSION

The highest number of intoxicated FIDs during the period in AP Vojvodina were mildly and completely inebriated. In the 4-year post-policy period (2010-2013), the number of FIDs and average BAC levels of inebriated FIDs did not significantly change. The abolition of a permissible BAC should be considered.

Witnesses stumbling down memory lane: The effects of alcohol intoxication, retention interval, and repeated interviewing

Intoxicated eyewitnesses are often discredited by investigators and in court, but few studies have examined how alcohol affects witnesses' memory. The primary aim of the present study was to examine how intoxication (alcohol vs. control), retention interval (immediate vs. one week delay), and number of interviews (one vs. two interviews) affect witnesses' memory. The participants (N = 99) were randomly assigned to consume either orange juice or alcohol mixed with orange juice, and they all witnessed a filmed mock crime afterwards. The recall took place either (a) immediately and after a one week delay or (b) after a one week delay only. No main effect of alcohol was found on the quantity or quality of the witnesses' statements. Both intoxicated and sober witnesses recalled more details, and were more accurate, during immediate compared to delayed recall. For witnesses interviewed twice, an average of 30% new details were provided in the second compared to the first interview, and these were highly accurate. In sum, contrary to what one can expect, intoxicated witnesses with a low to moderate blood alcohol concentration (below 0.10%) were reliable witnesses.

Acute effects of moderate alcohol on psychomotor, set shifting, and working memory function in older and younger social drinkers

ABSTRACT.

OBJECTIVE

Despite substantial attention being paid to the health benefits of moderate alcohol intake as a lifestyle, the acute effects of alcohol on psychomotor and working memory function in older adults are poorly understood.

METHOD

The effects of low to moderate doses of alcohol on neurobehavioral function were investigated in 39 older (55-70 years; 15 men) and 51 younger (25-35 years; 31 men) social drinkers. Subjects received one of three randomly assigned doses (placebo, .04 g/dl, or .065 g/dl target breath alcohol concentration). After beverage consumption, they completed the Trail Making Test Parts A and B and a working memory task requiring participants to determine whether probe stimuli were novel or had been presented in a preceding set of cue stimuli. Efficiency of working memory task performance was derived from accuracy and reaction time measures.

RESULTS

Alcohol was associated with poorer Trail Making Test Part B performance for older subjects. Working memory task results suggested an Age × Dose interaction for performance efficiency, with older but not younger adults demonstrating alcohol-related change. Directionality of change and whether effects on accuracy or reaction time drove the change depended on the novelty of probe stimuli.

CONCLUSIONS

This study replicates previous research indicating increased susceptibility of older adults to moderate alcohol-induced psychomotor and set-shifting impairment and suggests such susceptibility extends to working memory performance. Further research using additional tasks and assessing other neuropsychological domains is needed. (J. Stud. Alcohol Drugs, 75, 870-879, 2014).

Experiences of Injuries and Injury Reporting among Swedish Skydivers

The objective was to illuminate the experience of injuries and the process of injury reporting within the Swedish skydiving culture. Data contained narrative interviews that were subsequently analyzed with content analysis. Seventeen respondents (22–44 years) were recruited at three skydiving drop zones in Sweden. In the results injury events related to the full phase of a skydive were described. Risk of injury is individually viewed as an integrated element of the recreational activity counterbalanced by its recreational value. The human factor of inadequate judgment such as miscalculation and distraction dominates the descriptions as causes of injuries. Organization and leadership act as facilitators or constrainers for reporting incidents and injuries. On the basis of this study it is interpreted that safety work and incident reporting in Swedish skydiving may be influenced more by local drop zone culture than the national association regulations. Formal and informal hierarchical structures among skydivers seem to decide how skydiving is practiced, rules are enforced, and injuries are reported. We suggest that initial training and continuing education need to be changed from the current top-down to a bottom-up perspective, where the individual skydiver learns to see the positive implications of safety work and injury reporting.

A review of alcohol-impaired driving: the role of blood alcohol concentration and complexity of the driving task

The operation of a motor vehicle requires the integrity of sensory, motor, and intellectual faculties. Impairment of these faculties following the consumption of alcohol has been studied extensively through laboratory, closed-course and on-road driving, and epidemiological studies. The scientific literature was reviewed critically, with a focus on low-to-moderate blood alcohol concentrations (BAC ≤ 0.100%), to identify the most reliable determinants of alcohol-impaired driving. Variables such as age, gender, driving skill, and tolerance were shown to have limited impact on impairment. It was concluded the most relevant variables are BAC and complexity of the driving task. The scientific literature provides a high degree of confidence to support the conclusion that a BAC of 0.050% impairs faculties required in the operation of a motor vehicle. Whether impairment is apparent depends upon the complexity of the driving task, which applies to both study design and actual driving.

The influence of acute and chronic alcohol consumption on response time distribution in adolescent rhesus macaques

BACKGROUND

Analysis of the distribution of reaction times (RTs) in behavioral tasks can illustrate differences attributable to changes in attention, even when no change in mean RT is observed. Detrimental attentional effects of both acute and chronic exposure to alcohol may therefore be revealed by fitting RT data to an ex-Gaussian probability density function which identifies the proportion of long-RT responses.

METHODS

Adolescent male rhesus macaques completed a 5-choice serial reaction time task (5CSRT) after acute alcohol consumption (up to 0.0, 1.0 and 1.5 g/kg). Monkeys were next divided into chronic alcohol (N = 5) and control groups (N = 5); the experimental group consumed 1.5-3.0 g/kg alcohol for 200 drinking sessions. Unintoxicated performance in the 5CSRT task was determined systematically across the study period and the effect of acute alcohol was redetermined after the 180th drinking session. The effect of extended abstinence from chronic alcohol was determined across 90 days.

RESULTS

Acute alcohol exposure dose-dependently reduced the probability of longer RT responses without changing the mean or the standard deviation of the RT distribution. The RT distribution of control monkeys tightened across 10 months whereas that of the chronic alcohol group was unchanged. Discontinuation from chronic alcohol increased the probability of long RT responses with a difference from control animals observed after 30 days of discontinuation.

CONCLUSIONS

Alcohol consumption selectively affected attention as reflected in the probability of long RT responses. Acute alcohol consumption focused attention, chronic alcohol consumption impaired the maturation of attention across the study period and alcohol discontinuation impaired attention.

Low-Dose Alcohol Effects on Attention in Adolescents

Objective: Relatively little is known about the effects of low-dose alcohol effects on attentional performance in adolescents. In the present study, we examined these effects compared to those in adults. Method: 44 healthy subjects (21 adolescents and 23 adults) received either an alcoholic cocktail (average blood alcohol concentration: 0.054 %) or a placebo drink (randomized placebo-controlled). Before and after consuming the drink, participants completed tests on Alertness, Working Memory, Flexibility and Divided Attention. Results: Significant effects were found for the subtest Flexibility, which showed less improvement in the adolescents with alcohol compared to the non-alcohol condition and adults. Furthermore, an age-independent alcohol-induced impairment of the subtest Working Memory was observed. Conclusions: These findings point to a particular vulnerability for alcohol effects in adolescents regarding cognitive flexibility.

Differential effects of moderate alcohol consumption on motion and contrast processing

Although a moderate blood alcohol concentration already affects attention, an effect on early visual processing is still questionable. Using psychophysical measures and visually evoked potentials (VEP), we examined the effects of alcohol on the processing of contrast and motion features. In our tasks, two lateralized stimuli were briefly presented, and participants had to identify either the stimulus of higher contrast or motion coherence. In the contrast task, alcohol was found to decrease the discrimination ability and induced a global attenuation of VEP amplitudes. In the motion task, discrimination was not impaired. VEP amplitudes were reduced contralateral to the target position, indicating an effect of alcohol on the deployment of visuospatial attention. In sum, our data suggest that specialized areas for motion and contrast processing within the visual cortex are differently sensitive to moderate alcohol exposure.

Speeches, strangers, and alcohol use: the role of context in social stress response dampening

According to the Stress Response Dampening model, problem drinking develops after learning that alcohol limits the stress response in anxiety-provoking situations. However, laboratory-based studies testing alcohol's effects on social anxiety have yielded mixed results. The current study was the first to examine stress response dampening across two contexts: a performance-based (a speech) and an interaction-based (a conversation) social situation. Undergraduates (N = 62; M(age) = 22.85; 31% women; 81% Caucasian) were randomly assigned to consume an alcoholic (target BAC = .08%; n = 22), placebo (n = 20), or nonalcoholic control (n = 20) beverage followed by the anxiety-inducing social tasks. Results revealed a 3 (alcohol condition) × 2 (social task condition) × 4 (measurement point) interaction, controlling for baseline subjective state anxiety and trait social anxiety. The pattern of scores over the course of the task varied across alcohol conditions for the speech, but not the conversation. Specifically, participants in the alcohol and placebo conditions evidenced increased subjective anxiety following the first measurement point prior to the speech and their anxiety remained elevated at all subsequent measurements. Participants in the nonalcoholic control condition evidenced stable subjective anxiety ratings for all speech measurement points. Results did not support stress response dampening for either type of social situation. Instead, the only between-group difference found was that the placebo group reported greater subjective anxiety than the nonalcoholic control group after the speech. Concerns about alcohol's negative effects on one's performance might have led to increased anxiety. Findings shed light on previous inconsistent findings and highlight the need to consider context and timing in understanding drinking to cope with social anxiety.

The relationship between serious injury and blood alcohol concentration (BAC) in fatal motor vehicle accidents: BAC = 0.01% is associated with significantly more dangerous accidents than BAC = 0.00%

AIM

To analyze the severity of automotive injuries associated with blood alcohol concentration (BAC) in increments of 0.01%.

DESIGN/SETTING

Epidemiological study using the Fatality Analysis Reporting System.

PARTICIPANTS

All people in US fatal automotive accidents, 1994-2008 (n = 1 495 667).

MEASUREMENTS

The ratio of serious: non-serious injuries for drivers, by BAC.

FINDINGS

Accident severity increases significantly even when the driver is merely 'buzzed', a finding that persists after standardization for various confounding factors. Three mechanisms mediate between buzzed driving and high accident severity: compared to sober drivers, buzzed drivers are significantly more likely to speed, to be improperly seatbelted and to drive the striking vehicle. In addition, there is a strong 'dose-response' relationship for all three factors in relation to accident severity (e.g. the greater the BAC, the greater the average speed of the driver and the greater the severity of the accident).

CONCLUSIONS

The severity of life-threatening motor vehicle accidents increases significantly at blood alcohol concentrations (BACs) far lower than the current US limit of 0.08%. Lowering the legal limit could save lives, prevent serious injuries and reduce financial and social costs associated with motor vehicle accidents.

Functional biomarkers for the acute effects of alcohol on the central nervous system in healthy volunteers

The central nervous system (CNS) effects of acute alcohol administration have been frequently assessed. Such studies often use a wide range of methods to study each of these effects. Unfortunately, the sensitivity of these tests has not completely been ascertained. A literature search was performed to recognize the most useful tests (or biomarkers) for identifying the acute CNS effects of alcohol in healthy volunteers. All tests were grouped in clusters and functional domains. Afterwards, the effect of alcohol administration on these tests was scored as improvement, impairment or as no effect. Furthermore, dose-response relationships were established. A total number of 218 studies, describing 342 different tests (or test variants) were evaluated. Alcohol affected a wide range of CNS domains. Divided attention, focused attention, visuo-motor control and scales of feeling high and of subjective drug effects were identified as the most sensitive functional biomarkers for the acute CNS effects of alcohol. The large number of CNS tests that are used to determine the effects of alcohol interferes with the identification of the most sensitive ones and of drug-response relationships. Our results may be helpful in selecting rational biomarkers for studies investigating the acute CNS effects of alcohol or for future alcohol- interaction studies.

Attention to social threat as a vulnerability to the development of comorbid social anxiety disorder and alcohol use disorders: an avoidance-coping cognitive model

Despite the frequent comorbidity of social anxiety disorder and alcohol use disorders, no theoretical model currently exists to explain the specific mechanisms underlying the comorbidity between these two disorders. An integration of existing theoretical models and empirical evidence across the social anxiety and alcohol use literatures is presented as the Avoidance-Coping Cognitive Model, which proposes that socially anxious individuals may be particularly vulnerable to the anxiolytic effects of alcohol through reductions in attention biases to social threat. The disproportionate reduction in anxiety may then make alcohol an attractive method of avoidance coping. Gaps in the empirical literature are reviewed in light of this model as future directions are suggested.