Recent laboratory studies have shown that men display more risk-taking behavior in decision-making tasks following stress, whilst women are more risk-aversive or become more task-focused. In addition, these studies have shown that sex differences are related to levels of the stress hormone cortisol (indicative of activation of the hypothalamus-pituitary-adrenocortical-axis): the higher the levels of cortisol the more risk-taking behavior is shown by men, whereas women generally display more risk-aversive or task-focused behavior following higher levels of cortisol. Here, we assessed whether such relationships hold outside the laboratory, correlating levels of cortisol obtained during a job-related assessment procedure with decision-making parameters in the Cambridge Gambling Task (CGT) in male and female police recruits. The CGT allows for discriminating different aspects of reward-based decision-making. In addition, we correlated levels of alpha-amylase [indicative of activation of the sympatho-adrenomedullary-axis (SAM)] and decision-making parameters. In line with earlier studies men and women only differed in risk-adjustment in the CGT. Salivary cortisol levels correlated positively and strongly with risk-taking measures in men, which was significantly different from the weak negative correlation in women. In contrast, and less strongly so, salivary alpha-amylase levels correlated positively with risk-taking in women, which was significantly different from the weak negative correlation with risk-taking in men. Collectively, these data support and extend data of earlier studies indicating that risky decision-making in men and women is differently affected by stress hormones. The data are briefly discussed in relation to the effects of stress on gambling.

Driving with a hangover is a common phenomenon, and professional drivers acknowledge that their driving is impaired. Therefore, future experimental research should examine the magnitude of impairment while driving with an alcohol hangover.

BackgroundThe aim of this study was to examine differences in alcohol consumption and its consequences when consumed alone and when mixed with energy drinks.MethodsA survey was conducted among Dutch students at Utrecht University and the College of Utrecht. We collected data on alcohol consumption and alcohol-related consequences of alcohol consumed alone and/or alcohol mixed with energy drinks (AMED). The data were analyzed using a retrospective within-subject design, comparing occasions when subjects consumed AMED with those when they consumed alcohol only in the past 30 days.ResultsA representative sample of 6002 students completed the survey, including 1239 who consumed AMED. Compared with consuming alcohol only, when consuming AMED, students consumed significantly fewer alcoholic drinks on an average drinking day (6.0 versus 5.4, respectively), and reported significantly fewer drinking days in the previous month (9.2 versus 1.4), significantly fewer days being drunk (1.9 versus 0.5), and significantly fewer occasions of consuming more than four (female)/five (male) alcoholic drinks (4.7 versus 0.9). The maximum number of mixed alcoholic drinks (4.5) in the previous month was significantly lower when compared with occasions when they consumed alcohol only (10.7). Accordingly, the mean duration of a drinking session was significantly shorter when mixing alcoholic drinks (4.0 versus 6.0 hours). Finally, when consuming AMED, significantly fewer alcohol-related consequences were reported (2.6) for the previous year, including driving a car while intoxicated, taking foolish risks, or being injured or hurt, as compared with alcohol-related consequences when consuming alcohol only (4.9).ConclusionMixing alcohol with energy drinks decreases overall alcohol consumption, and decreases the likelihood of experiencing negative alcohol-related consequences.

This study examined the relationship between consumption of caffeinated beverages and alcohol, and effects on next day hangover severity. In 2010, a survey funded by Utrecht University was conducted among N=549 Dutch students. Beverages consumed on their latest drinking session that produced a hangover were recorded. Hangover severity was scored using the Acute Hangover Scale. No significant correlation between caffeine use and hangover severity was found. Subjects who mixed alcohol with colas consumed significantly more alcohol than those who drank alcohol alone (p=0.001), or mixed alcohol with energy drinks (p=0.001). Future studies with larger sample sizes should confirm these findings.

Risk-taking behavior is a major determinant of health and plays a central role in various diseases. Therefore, a brief questionnaire was developed to assess risk taking among young adults with known different levels of risk-taking behavior (social drinkers and recreational drug users). In Study 1, N = 522 university students completed the RT-18 risk taking questionnaire. N = 100 students were retested after 2 to 4 weeks and performed the Cambridge Gambling Task (CGT). Mean RT-18 score was 7.69 and Cronbach’s alpha was 0.886. The test-retest reliability was r = 0.94. Significant correlation was found between the RT-18 score and CGT scores of risk taking, bet proportion, and risk adjustment. In Study 2, N = 7834 young adult social drinkers, and recreational drug users, mean RT-18 score was 9.34 and Cronbach’s alpha was 0.80. Factor analysis showed that the RT-18 comprises two factors assessing level of risk-taking behavior and risk assessment. Men scored significantly higher than women on the RT-18. Recreational drug users had significantly higher scores when compared to social drinkers. In Study 3 of N = 1000 students, construct validity was confirmed by showing that the RT-18 outcome correlates significantly with scores on the Stimulating-Instrumental Risk Inventory. In conclusion, the RT-18 is a valid and reliable screening tool to differentiate levels of risk-taking behavior. This short scale is quick and practical to administer, imposing minimal demands on participants. The RT-18 is able to differentiate risk taking and risk assessment which can help target appropriate intervention strategies.

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This paper describes the methodology of the Utrecht Student Survey. This online survey was conducted in June 2011 by 6002 students living in Utrecht, The Netherlands. The aim of the survey was to determine the potential impact of mixing alcoholic beverages with energy drinks on overall alcohol consumption and alcohol-related consequences. In contrast to most previous surveys conducted on this topic, the current survey used a more appropriate within-subject design, comparing the alcohol consumption of individuals who consume alcohol mixed with energy drinks on occasions. Specifically, a comparison was conducted to examine the occasions during which these individuals consume this mixture versus occasions during which they consume alcohol alone. In addition to energy drinks, the consumption of other non-alcoholic mixers was also assessed when combined with alcoholic beverages. Furthermore, the reasons for consuming energy drinks alone or in combination with alcohol were investigated, and were compared to reasons for mixing alcohol with other non-alcoholic beverages. Finally, personality characteristics and the level of risk-taking behavior among the individuals were also assessed to explore their relationship with alcohol consumption. The Utrecht Student Survey will be replicated in the USA, Australia, and the UK. Results will be pooled, but also examined for possible cross-cultural differences.

In whole blood from splenectomized subjects (n = 20), red cells showed a significant increase of mean surface area (MSA), mean cell volume (MCV), MSA/MCV-ratio and osmotic resistance, with the mean cell haemoglobin concentration (MCHC) being decreased. Studies on red cell populations of different cell age revealed that the increase of MSA affects younger and older cells, whereas the increase of MCV can mainly be ascribed to young cells with low density. The increased osmotic resistance is mainly determined by older cells due to a more favourable MSA/MCV-ratio. Shortly after splenectomy (n = 5) the MSA of younger and older cells increased, whereas the increase of MCV affected only young cells with a lowered density; moreover, the MSA/MCV-ratio increased in older cells in particular, resulting in a relatively greater increase of osmotic resistance. An impaired maturation of the reticulocyte may underlie the initial increase of MSA and MCV of young cells, but the present results contradict the current view that delayed maturation explains the changes in morphology and osmotic resistance of asplenic red cells.