Effects of stress and dietary tryptophan enhancement on craving for alcohol in binge and non-binge heavy drinkers

Stress is known to play an important role in alcohol abuse, whereas binge drinking may increase individuals' susceptibility to the development of alcohol dependence. We set out to investigate whether binge drinkers (BDs) or non-BDs (NBDs) are at a greater risk of an increase in their desire for alcohol following experimental stress induction (modified Trier Social Stress Test; Experiment 1) and to explore the biological mechanisms underlying such an effect (Experiment 2). Preclinical evidence suggests that serotonin may mediate stress-induced reinstatement of alcohol intake. We therefore tested whether dietary tryptophan (TRP) enhancement would modulate stress-induced desire for alcohol and whether it would affect the two populations (BD/NBD) differently. In Experiment 1 (14 NBDs, 10 BDs; mean weekly alcohol intake 50.64 U), stress induction selectively increased strong desire for alcohol compared with the nonstressful condition in BDs. Throughout the experiment, BDs reported greater negative reinforcement type of craving than NBDs, but also a higher expectancy of alcohol-induced negative effects. In Experiment 2, 41 participants (22 NBDs, 19 BDs; mean alcohol intake 38.81 U) were given either the TRP-rich (TRP+; 9 BDs, 11 NBD) or the control (CTR; 10 BD, 11 NBD) diet before undergoing stress induction. In BDs, the TRP+ diet prevented the stress-induced increase in strong desire that was observed in individuals receiving the CTR diet. In NBDs, the TRP+ diet appeared to facilitate an increase in strong desire. These findings suggest that BDs may indeed be at a greater risk than NBDs of an increase in their craving for alcohol when stressed. Furthermore, whereas enhancement of 5-hydroxytryptamine function may moderate the impact of stress on craving in BDs, it seems to facilitate stress-induced craving in NBDs, suggesting that the serotonergic system may be differentially involved depending on individual binge drinking status.

Anxiety, sedation, and simulated driving in binge drinkers

The current study evaluated the relationships among trait anxiety, subjective response to alcohol, and simulated driving following a simulated alcohol binge. Sixty drinkers with a binge history completed the State Trait Anxiety Inventory (STAI), the Alcohol Use Questionnaire, and subsequently completed a driving simulation. Participants were then administered 0.2 g/kg ethanol at 30-min intervals (cumulative dose 0.8 g/kg). Following alcohol consumption, the Biphasic Alcohol Effects Scale (BAES) and visual analog scales of subjective impairment and driving confidence were administered, after which simulated driving was reassessed. Due to the emphasis on simulated driving after drinking in the current study, subjective response to alcohol (i.e., self-reported sedation, stimulation, impairment, and confidence in driving ability) was assessed once following alcohol consumption, as this is the time when drinkers tend to make decisions regarding legal driving ability. Alcohol increased driving speed, speeding tickets, and collisions. Sedation following alcohol predicted increased subjective impairment and decreased driving confidence. Subjective impairment was not predicted by sensitivity to stimulation or trait anxiety. High trait anxiety predicted low driving confidence after drinking and this relationship was mediated by sedation. Increased speed after alcohol was predicted by sedation, but not by trait anxiety or stimulation. Anxiety, combined with the sedating effects of alcohol, may indicate when consumption should cease. However, once driving is initiated, sensitivity to sedation following alcohol consumption is positively related to simulated driving speed.

[Neurocognitive anomalies associated with the binge drinking pattern of alcohol consumption in adolescents and young people: a review]

Binge drinking (BD) is the most common problematic drinking pattern during adolescence and youth. At the same time, it is a period marked by profound structural and functional brain changes, which may be affected by heavy alcohol consumption. In recent years, a considerable number of studies that attempt to characterize the effects of BD on the brain has been published. However, to date there is not any critical review in Spanish language on neurostructural, neurophysiological and cognitive consequences that may result from the maintenance of a BD pattern of alcohol consumption during adolescence and youth. The purpose of this review is to critically summarize the main research results on the effects of BD on the brain. To this end, a literature search in databases Web of Knowledge, PubMed and PsycINFO for the period 2000-2013 was performed. In general, studies agree that BD is associated with 1) lower performance on tasks assessing cognitive processes such as attention, memory and executive functions, 2) structural changes (in white matter and gray matter) in different brain regions and 3) neurophysiological abnormalities (hyper/hypoactivation) linked to different cognitive processes. These results, although still need to be contrasted, warn about important consequences that could result from the persistence of BD on a young and still maturing brain.

A phenotypic structure and neural correlates of compulsive behaviors in adolescents

BACKGROUND

A compulsivity spectrum has been hypothesized to exist across Obsessive-Compulsive disorder (OCD), Eating Disorders (ED), substance abuse (SA) and binge-drinking (BD). The objective was to examine the validity of this compulsivity spectrum, and differentiate it from an externalizing behaviors dimension, but also to look at hypothesized personality and neural correlates.

METHOD

A community-sample of adolescents (N=1938; mean age 14.5 years), and their parents were recruited via high-schools in 8 European study sites. Data on adolescents' psychiatric symptoms, DSM diagnoses (DAWBA) and substance use behaviors (AUDIT and ESPAD) were collected through adolescent- and parent-reported questionnaires and interviews. The phenotypic structure of compulsive behaviors was then tested using structural equation modeling. The model was validated using personality variables (NEO-FFI and TCI), and Voxel-Based Morphometry (VBM) analysis.

RESULTS

Compulsivity symptoms best fit a higher-order two factor model, with ED and OCD loading onto a compulsivity factor, and BD and SA loading onto an externalizing factor, composed also of ADHD and conduct disorder symptoms. The compulsivity construct correlated with neuroticism (r=0.638; p ≤ 0.001), conscientiousness (r=0.171; p ≤ 0.001), and brain gray matter volume in left and right orbitofrontal cortex, right ventral striatum and right dorsolateral prefrontal cortex. The externalizing factor correlated with extraversion (r=0.201; p ≤ 0.001), novelty-seeking (r=0.451; p ≤ 0.001), and negatively with gray matter volume in the left inferior and middle frontal gyri.

CONCLUSIONS

Results suggest that a compulsivity spectrum exists in an adolescent, preclinical sample and accounts for variance in both OCD and ED, but not substance-related behaviors, and can be differentiated from an externalizing spectrum.

Using ecological momentary assessment in testing the effectiveness of an alcohol intervention: a two-arm parallel group randomized controlled trial

Background

Alcohol consumption of college students has a fluctuating nature, which might impact the measurement of intervention effects. By using 25 follow-up time-points, this study tested whether intervention effects are robust or might vary over time.

Methods

Data were used from a two-arm parallel group randomized controlled trial applying ecological momentary assessment (EMA) with 30 data time-points in total. Students between 18 and 24 years old who reported heavy drinking in the past six months and who were ready to change their alcohol consumption were randomly assigned to the experimental (n = 456: web-based brief alcohol intervention) and control condition (n = 451: no intervention). Outcome measures were weekly alcohol consumption, frequency of binge drinking, and heavy drinking status.

Results

According to the intention-to-treat principle, regression analyses revealed that intervention effects on alcohol consumption varied when exploring multiple follow-up time-points. Intervention effects were found for a) weekly alcohol consumption at 1, 2, 3, 4, and 7 weeks follow-up, b) frequency of binge drinking at 1, 2, 7, and 12 weeks follow-up, and c) heavy drinking status at 1, 2, 7, and 16 weeks follow-up.

Conclusions

This research showed that the commonly used one and six month follow-up time-points are relatively arbitrary and not using EMA might bring forth erroneous conclusions on the effectiveness of interventions. Therefore, future trials in alcohol prevention research and beyond are encouraged to apply EMA when assessing outcome measures and intervention effectiveness.

Trial registration

Netherlands Trial Register NTR2665

Global T-wave inversions with isolated hypomagnesemia

BACKGROUND

The physiological actions of magnesium within the cardiac conduction system and myocytes have yet to be fully elucidated. Because concurrent hypocalcemia or hypokalemia were also present in previous human reports, specific electrocardiographic effects of isolated hypomagnesemia have not been clearly delineated.

OBJECTIVE

We report a case in which dynamic electrocardiogram (ECG) changes were demonstrated in isolated hypomagnesemia.

CASE REPORT

A 37-year-old man with history of heavy alcohol use was admitted for syncope. The ECG showed global T-wave inversions with prolonged corrected QT (QTc) duration on ECG. Extensive work-up including cardiac catheterization was unremarkable. His serum magnesium was noted to be low at 1.1 mg/dL, and his serum calcium and potassium were within normal limits. The patient received magnesium infusion with subsequent ECGs showing resolution of his global T-wave inversions and prolonged QTc.

CONCLUSION

This case is unique because it reports dynamic ECG changes in a patient with isolated hypomagnesemia. Although isolated hypomagnesemia is commonly believed to result in dysrhythmia, we were unaware of any previous cases of ECG abnormalities in humans. Clinically, we advise checking serum magnesium and correcting hypomagnesemia when prolonged QTc duration and global T-wave inversions are seen on ECG.

Holiday heart syndrome revisited after 34 years

The cardiovascular effects of alcohol are well known. However, most research has focused on the beneficial effects (the "French paradox") of moderate consumption or the harmful consequences, such as dilated cardiomyopathy, associated with heavy consumption over an extended period. An association between the ingestion of acute alcohol and onset of cardiac arrhythmias was first reported in the early 70's. In 1978, Philip Ettinger described "Holiday heart syndrome" (HHS) for the first time, as the occurrence, in healthy people without heart disease known to cause arrhythmia, of an acute cardiac rhythm disturbance, most frequently atrial fibrillation, after binge drinking. The name is derived from the fact that episodes were initially observed more frequently after weekends or public holidays. Since the original description of HHS, 34 years have passed and new research in this field has increased the volume of knowledge related to this syndrome. Throughout this paper the authors will comprehensively review most of the available data concerning HHS and highlight the questions that remain unresolved.

Binge drinking and blood pressure: cross-sectional results of the HAPIEE study

OBJECTIVES

To investigate whether binge drinking pattern influences blood pressure independently from drinking volume or whether it modifies the effect of volume of drinking.

METHODS

We used cross-sectional data from population samples of 7559 men and 7471 women aged 45-69 years in 2002-05, not on antihypertensive medication, from Russia, Poland and Czech Republic. Annual alcohol intake, drinking frequency and binge drinking (≥ 100 g in men and ≥ 60 g in women in one session at least once a month) were estimated from graduated frequency questionnaire. Blood pressure was analysed as continuous variables (systolic and diastolic pressure) and a binary outcome (≥ 140/90 mm Hg).

RESULTS

In men, annual alcohol intake and drinking frequency were strongly associated with blood pressure. The odds ratio of high blood pressure for binge drinking in men was 1.62 (95% CI 1.45-1.82) after controlling for age, country, body mass index, education and smoking; additional adjustment for annual alcohol intake reduced it to 1.20 (1.03-1.39). In women, the fully adjusted odds ratio of high blood pressure for binge drinking was 1.31 (1.05-1.63). Binge drinking did not modify the effect of annual alcohol intake. Consuming alcohol as wine, beer or spirits had similar effects.

CONCLUSIONS

The results suggest that the independent long-term effect of binge drinking was modest, that binge drinking did not modify the effect of alcohol intake, and that different alcoholic beverages had similar effects on blood pressure.

Reversed scototaxis during withdrawal after daily-moderate, but not weekly-binge, administration of ethanol in zebrafish

Alcohol abuse can lead to severe psychological and physiological damage. Little is known, however, about the relative impact of a small, daily dose of alcohol (daily-moderate schedule) versus a large, once per week dose (weekly-binge schedule). In this study, we examined the effect of each of these schedules on behavioural measures of anxiety in zebrafish (Danio rerio). Adult wild-type zebrafish were administered either 0.2% ethanol on a daily-moderate schedule or 1.4% ethanol on a weekly-binge schedule for a period of 21 days, and then tested for scototaxis (preference for darkness) during withdrawal. Compared to a control group with no alcohol exposure, the daily-moderate group spent significantly more time on the light side of the arena (indicative of decreased anxiety) on day two of withdrawal, but not day 9 of withdrawal. The weekly-binge group was not significantly different from the control group on either day of withdrawal and showed no preference for either the light or dark zones. Our results indicate that even a small dose of alcohol on a daily basis can cause significant, though reversible, changes in behaviour.

Increased cortical activity in binge drinkers during working memory task: a preliminary assessment through a functional magnetic resonance imaging study

BACKGROUND

Cerebral dysfunction is a common feature of both chronic alcohol abusers and binge drinkers. Here, we aimed to study whether, at equated behavioral performance levels, binge drinkers exhibited increased neural activity while performing simple cognitive tasks.

METHODS

Thirty-two participants (16 binge drinkers and 16 matched controls) were scanned using functional magnetic resonance imaging (fMRI) while performing an n-back working memory task. In the control zero-back (N0) condition, subjects were required to press a button with the right hand when the number "2" was displayed. In the two-back (N2) condition, subjects had to press a button when the displayed number was identical to the number shown two trials before.

RESULTS

fMRI analyses revealed higher bilateral activity in the pre-supplementary motor area in binge drinkers than matched controls, even though behavioral performances were similar. Moreover, binge drinkers showed specific positive correlations between the number of alcohol doses consumed per occasion and higher activity in the dorsomedial prefrontal cortex, as well as between the number of drinking occasions per week and higher activity in cerebellum, thalamus and insula while performing the N2 memory task.

CONCLUSIONS

Binge alcohol consumption leads to possible compensatory cerebral changes in binge drinkers that facilitate normal behavioral performance. These changes in cerebral responses may be considered as vulnerability factors for developing adult substance use disorders.

Amitifadine, a triple monoamine uptake inhibitor, reduces binge drinking and negative affect in an animal model of co-occurring alcoholism and depression symptomatology

The co-occurrence of alcoholism and depression is highly prevalent and difficult to treat. In an animal model of binge drinking that exhibits abstinence-induced behaviors reminiscent of negative affective states, the triple monoamine uptake inhibitor, amitifadine, produced a selective, dose dependent attenuation of binge drinking. Amitifadine also reversed abstinence-induced increases in the intracranial self-stimulation threshold, a model of anhedonia, and immobility in the forced swim test, reflecting behavioral despair. In view of the safety profile of amitifadine in humans, including low risk for weight gain, lack of sexual side effects, and low potential for abuse, we hypothesize that amitifadine will be effective in treating co-occurring alcoholism and depression.

Acute tolerance to alcohol in at-risk binge drinkers

Studies of the impairing effects of alcohol on behavior often show greater tolerance in heavy drinkers compared with light drinkers, suggesting a causal link between heavy consumption and tolerance. Tolerance also develops during the time course of a single drinking episode, and this "acute tolerance" might play an important role in the escalation to heavy drinking. The present study examined the development of acute tolerance to the impairing effects of alcohol on motor coordination and inhibitory control in a group of at-risk binge drinkers (n = 20) and a group of nonrisk moderate drinkers (n = 20). Participants performed the testing battery in response to placebo and a moderate dose of alcohol (0.65 g/kg) twice at comparable blood alcohol concentrations (BACs): once on the ascending limb and once on the descending limb of the blood alcohol curve. Results showed marked acute tolerance to the impairing effects of alcohol on motor coordination in the at-risk drinkers. By contrast, no recovery of motor skill was observed in the nonrisk drinkers. Regarding inhibitory control, both groups remained impaired on both the ascending and descending limbs, indicating no acute tolerance in either group. The findings suggest that at-risk binge drinkers display a faster recovery in their ability to execute versus inhibit action under alcohol. Such an "activational bias" of behavior could account for their continued alcohol consumption and impulsive behaviors while intoxicated, especially as BAC begins to decline.