Cecile A. Marczinski

Effects of energy drinks mixed with alcohol on behavioral control: Risks for college students consuming trendy cocktails

BACKGROUND There has been a dramatic rise in the consumption of alcohol mixed with energy drinks (AmED) in young people. AmED have been implicated in risky drinking practices and greater accidents and injuries have been associated with their consumption. Despite the increased popularity of these beverages (e.g., Red Bull and vodka), there is little laboratory research examining how the effects of AmED differ from alcohol alone. This experiment was designed to investigate if the consumption of AmED alters neurocognitive and subjective measures of intoxication compared with the consumption of alcohol alone. METHODS Participants (n=56) attended 1 session where they were randomly assigned to receive one of 4 doses (0.65 g/kg alcohol, 3.57 ml/kg energy drink, AmED, or a placebo beverage). Performance on a cued go/no-go task was used to measure the response of inhibitory and activational mechanisms of behavioral control following dose administration. Subjective ratings of stimulation, sedation, impairment, and level of intoxication were recorded. RESULTS Alcohol alone impaired both inhibitory and activational mechanisms of behavioral control, as evidenced by increased inhibitory failures and increased response times compared to baseline performance. Coadministration of the energy drink with alcohol counteracted some of the alcohol-induced impairment of response activation, but not response inhibition. For subjective effects, alcohol increased ratings of stimulation, feeling the drink, liking the drink, impairment, and level of intoxication, and alcohol decreased the rating of ability to drive. Coadministration of the energy drink with alcohol increased self-reported stimulation, but resulted in similar ratings of the other subjective effects as when alcohol was administered alone. CONCLUSIONS An energy drink appears to alter some of the objective and subjective impairing effects of alcohol, but not others. Thus, AmED may contribute to a high-risk scenario for the drinker. The mix of impaired behavioral inhibition and enhanced stimulation is a combination that may make AmED consumption riskier than alcohol consumption alone.

Effects of energy drinks mixed with alcohol on information processing, motor coordination and subjective reports of intoxication

The consumption of alcohol mixed with energy drinks (AmED) has become a popular and controversial practice among young people. Increased rates of impaired driving and injuries have been associated with AmED consumption. The purpose of this study was to examine if the consumption of AmED alters cognitive processing and subjective measures of intoxication compared with the consumption of alcohol alone. Eighteen participants (nine men and nine women) attended four test sessions where they received one of four doses in random order (0.65 g/kg alcohol, 3.57 ml/kg energy drink, AmED, or a placebo beverage). Performance on a psychological refractory period (PRP) task was used to measure dual-task information processing and performance on the Purdue pegboard task was used to measure simple and complex motor coordination following dose administration. In addition, various subjective measures of stimulation, sedation, impairment, and level of intoxication were recorded. The results indicated that alcohol slowed dual-task information processing and impaired simple and complex motor coordination. The coadministration of the energy drink with alcohol did not alter the alcohol-induced impairment on these objective measures. For subjective effects, alcohol increased various ratings indicative of feelings of intoxication. More importantly, coadministration of the energy drink with alcohol reduced perceptions of mental fatigue and enhanced feelings of stimulation compared to alcohol alone. In conclusion, AmED may contribute to a high-risk scenario for a drinker. The mix of behavioral impairment with reduced fatigue and enhanced stimulation may lead AmED consumers to erroneously perceive themselves as better able to function than is actually the case.

Alcohol Mixed with Energy Drinks: Consumption Patterns and Motivations for Use in U.S. College Students

Binge drinking in college students is widespread and known to cause significant harms and health hazards for the drinker. One factor that may be exacerbating hazardous drinking in young people is the new popular trend of consuming alcohol mixed with energy drinks (AmED). However, rates of AmED use and motivations for AmED consumption in college students have not been well established. In this study, 706 undergraduate college students from a university in the United States participated in a web-based survey that queried self-reported alcohol, energy drink, and AmED use. In addition, motivations for using AmEDs were assessed. The results indicated that for all participants, 81% reported that they have tried at least one energy drink in the past and 36% reported consumption of at least one energy drink in the past 2 weeks. Alcohol consumption patterns were similar to findings from U.S. national surveys of college drinking, as 37% of respondents were classified as binge drinkers and 23% abstained from drinking. In the whole sample (including the alcohol abstainers), 44% reported trying AmED at least once and 9% reported AmED consumption at least once in the past 2 weeks. 78% of respondents agreed with the statement that AmEDs appeal to underage drinkers. When AmED users were asked about various motivations for consuming AmEDs, users reported that they consumed these beverages to get drunk and reduce sedation compared to alcohol alone. In conclusion, the consumption of AmEDs is common in U.S. college students. Motivations for using AmEDs include the reduction of the sedative effects of alcohol, an important interoceptive cue that one should stop drinking.

Increased sensitivity to the disinhibiting effects of alcohol in binge drinkers.

Heavy episodic alcohol use, or binge drinking, is a serious public health problem. Binge drinking is endemic in college students and has resulted in numerous alcohol-related tragedies, including acute alcohol poisonings, falls, and automobile collisions. Such negative outcomes might occur because binge drinkers are generally more impulsive, and this impulsivity might be exacerbated under alcohol. The purpose of this study was to examine this hypothesis by comparing the acute effects of alcohol on a cognitive measure of behavioral control in binge and nonbinge drinkers. The results indicated that binge drinkers act more impulsively and report feeling more stimulated under an acute 0.65 g/kg dose of alcohol compared to nonbinge drinkers. The present finding of a heightened disinhibitory reaction to alcohol in binge drinkers may help explain the link between impulsivity and problem drinking at a more fundamental level of behavioral control.

A longitudinal study of language decline in Alzheimer's disease and frontotemporal dementia

Language decline is usually the fastest and predominant change in primary progressive aphasia (PPA). In Alzheimers disease (AD), it is usually associated with global cognitive deficits. Decreased speech output, reduced conversational initiation, echolalia, and changes in the pragmatics of conversation are seen in the behavioral variant of frontotemporal dementia (FTD-bv), however, the evolution of language disturbance in FTD-bv patients is rarely examined systematically with a standardized language battery. We aimed to longitudinally track the nature of language change in FTD-bv, PPA, and AD using a standardized measure of language functioning. We also explored the nature of language deficits between semantic dementia (SD) patients and the fluent subgroup of PPA patients. The Western Aphasia Battery was administered to 105 AD, 20 FTD-bv, 54 PPA, and 10 SD patients on 2 occasions with approximately 1 year between assessments. Ninety-nine of these patients were examined an additional year. FTD-bv and PPA patients showed a faster language decline than AD patients. The eventual overlap in language functioning in FTD-bv and PPA suggests that these syndromes belong to the same spectrum of disorders. In conclusion, longitudinal language assessment provides us with a unique understanding of the evolution and progression of language deterioration in various dementias.

Dissociative antagonistic effects of caffeine on alcohol-induced impairment of behavioral control.

The present study examined the separate and combined effects of alcohol and caffeine on behavioral control in a context in which preliminary cues signaled the likelihood that a response should be executed or inhibited. Social drinkers (N = 12) performed a cued go/no-go task that measured control as the quick execution of responses to go targets and sudden suppression of responses to no-go targets. Performance was tested under 3 doses of caffeine (0.0 mg/kg, 2.0 mg/kg, and 4.0 mg/kg) in combination with 2 doses of alcohol (0.0 g/kg and 0.65 g/kg). Alcohol impaired both inhibitory and activational aspects of behavioral control. Caffeine antagonized alcohol effects on response execution but had no effect on inhibitory control. The findings highlight potential differences in how activational and inhibitory aspects of behavioral control respond to drug interactions.

Simulated driving performance of adults with ADHD: comparisons with alcohol intoxication

Previous research has demonstrated that adults with attention deficit/hyperactivity disorder (ADHD) are more likely to experience driving-related problems, which suggests that they may exhibit poorer driving performance. However, direct experimental evidence of this hypothesis is limited. The current study involved 2 experiments that evaluated driving performance in adults with ADHD in terms of the types of driving decrements typically associated with alcohol intoxication. Experiment 1 compared the simulated driving performance of 15 adults with ADHD to 23 adult control participants, who performed the task both while sober and intoxicated. Results showed that sober adults with ADHD exhibited decrements in driving performance compared to sober controls, and that the profile of impairment for the sober ADHD group did in fact resemble that of intoxicated drivers at the blood alcohol concentration level for legally impaired driving in the United States. Driving impairment of the intoxicated individuals was characterized by greater deviation of lane position, faster and more abrupt steering maneuvers, and increased speed variability. Experiment 2 was a dose-challenge study in which 8 adults with ADHD and 8 controls performed the driving simulation task under 3 doses of alcohol: 0.65g/kg, 0.45g/kg, and 0.0g/kg (placebo). Results showed that driving performance in both groups was impaired in response to alcohol, and that individuals with ADHD exhibited generally poorer driving performance than did controls across all dose conditions. Together the findings provide compelling evidence to suggest that the cognitive and behavioral deficits associated with ADHD might impair driving performance in such a manner as to resemble that of an alcohol intoxicated driver. Moreover, alcohol might impair the performance of drivers with ADHD in an additive fashion that could considerably compromise their driving skill even at blood alcohol concentrations below the legal limit.

Impulsivity and alcohol consumption in young social drinkers

Impulsivity may have different facets that contribute to drinking patterns in young people. This research examined how aspects of impulse control, especially the ability to inhibit a response, predicted recent alcohol use patterns in young social drinkers. Participants (N=109) between the ages of 18 and 21 performed a cued go/no-go task that required quick responses to go targets and the inhibition of responses to no-go targets. Participants also completed several questionnaires that assessed drinking habits (TLFB) and self-reported impulsivity (BIS-11). Regression analyses revealed that both the impulsivity questionnaire scores and the inhibitory failures observed on the behavioral task predicted various aspects of recent drinking. However, only the inhibitory failures from the behavioral task, and not the impulsivity questionnaire scores, predicted the highest number of drinks consumed on one occasion during the past month. These findings are consistent with the notion that impulsivity may have different components that may be contributing the drinking patterns, and this research suggests that the inability to withhold a response is a strong predictor of the binge use of alcohol.

Effects of d-amphetamine on behavioral control in stimulant abusers: the role of prepotent response tendencies

The present study examined the effects of d-amphetamine on the ability to execute and inhibit behavior in a context where preliminary information signaled the likelihood that a response should be executed or suppressed. Eight adults (5 men and 3 women) with a history of stimulant abuse performed a cued go no-go task that required quick responses to go targets and suppression of responses to no-go targets. Performance was tested under four oral doses of d-amphetamine, 0 (placebo), 5, 10 and 20 mg, administered double-blind and in mixed order. d-Amphetamine produced a dose-dependent increase in inhibitory failures following invalid go cues and had no effect on inhibitory failures following valid no-go cues. d-Amphetamine had little effect on response execution as measured by reaction time. Subjective and physiological effects of d-amphetamine were also observed. The findings demonstrate that stimulant effects on fundamental aspects of behavioral control can be mediated by environmental cues that alter response tendencies. Identification of environmental conditions in which stimulants are likely to disinhibit behavior could provide insight into mechanisms that underlie the association between long-term stimulant use and poor impulse control.

Acute alcohol tolerance on subjective intoxication and simulated driving performance in binge drinkers.

High rates of binge drinking and alcohol-related problems, including drinking and driving, occur among college students. Underlying reasons for the heightened impaired driving rates in this demographic group are not known. The authors hypothesized that acute tolerance to the interoceptive cues of intoxication may contribute to these maladaptive decisions to drive in binge drinkers. Groups of binge-drinking and non-binge-drinking college students (N = 28) attended sessions during which they received a moderate dose of alcohol (0.65 g/kg) or a placebo. The development of acute tolerance to subjective ratings of intoxication and simulated driving performance was assessed by comparing measures taken during the ascending phase and descending phases of the blood alcohol curve. Compared with placebo, alcohol increased ratings of intoxication and impaired multiple aspects of simulated driving performance in both binge and non-binge drinkers. During the descending phase of the blood alcohol curve, binge drinkers showed acute tolerance to alcohols effect on subjective intoxication, and this effect was accompanied by an increased rating of willingness to drive. By contrast, non-binge drinkers showed no acute tolerance.