Current Drug Abuse Reviews - Volume 3, Issue 2, 2010

This special issue of Current Drug Abuse Reviews is devoted to the alcohol hangover. Alcohol hangover can be described as the general misery felt the day after an evening of excessive alcohol consumption. Among students and young adults, alcohol hangover is reported as most frequently experienced alcohol-related consequence [1, 2]. However, alcohol hangovers are experienced by people of all ages and the consequences are often underestimated. Three examples below illustrate the impact alcohol hangover can have on job performance, health, and accident risk. First, alcohol hangovers have serious socioeconomic consequences. In a recent Norwegian study, 526 employees were interviewed about how alcohol and drug use may affected their workplace safety and productivity [3]. Absenteeism due to alcohol use (at least once during the past year) was reported by 6.2% of the employees, whereas 24.3% reported having a hangover at work. Absence, inefficiency and reduced productivity because of alcohol hangover was much more often reported than other substance abuse problems such as the use of illegal drugs (0.6%). About 25% of the interviewed sample was working in the transportation industry. This is of concern, since driving a car is a potentially dangerous activity which is likely to be impaired during alcohol hangover [4]. Hangovers were significantly more often reported by male employees younger than 35 years old. The latter was also found in a survey among 13.582 Australian workers [5]. This study further showed that high risk drinkers (i.e. over 5 and 7 alcoholic drinks per day for women and men, respectively) were more that 22 times more likely to be absent from work due to alcohol consumption. Second, having alcohol hangovers frequently is also an important health risk factor. For example, Kauhanen and coworkers [6] examined the relationship between hangover frequency and cardiovascular mortality in a Finnish sample. Men that reported having an alcohol hangover at least once a month had a 2.36-fold increased risk of cardiovascular death when compared to those with less frequent hangovers. These results were found after correcting for age and total alcohol consumption. Third, increased accident risk is common during hangover. This has also been reported in sports. Cherpitel et al. [7] compared alcohol consumption patterns of 389 injured skiers with 899 non-injured skiers. Injured skiers reported much more often (61%) having been drinking over the past 24 hours than uninjured skiers (19%). Most injured skiers reported not having their accident during intoxication, but more than 12 hours after their last drink, suggesting that hangover effects may have been involved in producing the accident. While many more examples can be given, the alcohol hangover has, to date, received surprisingly little scientific attention. This is in sharp contrast to other less common medical complaints and the high prevalence of alcohol hangover among the general public. Table 1 illustrates this discrepancy by comparing GOOGLE hits with PUBMED citations. Fig. (1) gives an overview of PUBMED citations over the past 60 years when searching for “alcohol” and “alcohol hangover”. It is evident from Fig. (1) that, although most alcohol researchers have been active in other research areas, the popularity of alcohol hangover research is on the increase. In 2009 alcohol hangover researchers from around the world united under the auspices of the Alcohol Hangover Research Group (AHRG). The goal of the AHRG is to achieve consensus on current research methodology, as well as instigating new research collaboration with the aim to elucidate the causes and consequences of the alcohol hangover, and develop effective hangover cures (Fig. 2). A website was launched (www.alcoholhangover.com) to raise the profile of alcohol hangover research. A research symposium and consensus meeting was organized by Dr. Stephens and Dr. Verster as a Satellite Meeting of the 33rd annual scientific meeting of the Research Society on Alcoholism, 26th June 2010 (see Fig. 3). Dr. Joris Verster of Utrecht University in the Netherlands kicked off the symposium with a scene setting presentation discussing the causes and consequences of the alcohol hangover. Dr. Verster pointed out that although hangover was the most prevalent and commonly recognized problem experienced in relation to alcohol, only some 400 alcohol hangover research papers had been published to date, compared with over 650,000 research papers dedicated to other aspects of alcohol consumption. As a result of the lack of scientific interest, much remains to be investigated to reveal the pathology of alcohol hangover and develop effective hangover cures.......

Research on human subjects analyzing blood and urine samples determined biological correlates that may explain the pathology of alcohol hangover. These analyses showed that concentrations of various hormones, electrolytes, free fatty acids, triglycerides, lactate, ketone bodies, cortisol, and glucose were not significantly correlated with reported alcohol hangover severity. Also, markers of dehydration (e.g., vasopressin) were not significantly related to hangover severity. Some studies report a significant correlation between blood acetaldehyde concentration and hangover severity, but most convincing is the significant relationship between immune factors and hangover severity. The latter is supported by studies showing that hangover severity may be reduced by inhibitors of prostaglandin synthesis. Several factors do not cause alcohol hangover but can aggravate its severity. These include sleep deprivation, smoking, congeners, health status, genetics and individual differences. Future studies should more rigorously study these factors as well as biological correlates to further elucidate the pathology of alcohol hangover.

Congeners are minor compounds other than ethanol that occur naturally in alcohol beverages as a result of distilling and fermenting processes. While ethanol itself is the main source of hangover (subjective distress) and other residual effects of alcohol (cognitive and behavioral), the role of the congeners is of interest due to the potential toxicity of many of them despite their minute quantities. Survey studies, while comparing beer to liquor to wine, have generally not addressed beverage effects that clearly differ in congener content. The few experimental studies indicate that the highest congener beverage (bourbon) results in more severe hangover ratings than does the beverage with essentially no congeners (vodka), although ethanol effects per se had a considerably stronger effect on hangover than did congener content. Safety-sensitive performance that was affected by alcohol intoxication the previous night (vigilance with reaction time; ataxia) was not differentially affected by bourbon versus vodka. The paucity of studies indicates more work is needed in order to have confidence in these results.

The consequences of alcohol consumption have risen high on health and social agendas in recent years. Although much work has focused on the physical problems associated with alcohol use, one theme that has emerged in alcohol research has been a focus on the effects of hangovers on functioning. This brief literature review specifically examines recent empirical investigations of the relationship between alcohol hangover and psychological performance and is tabled as an update to our earlier review of similar research (Stephens et al., 2008). A literature search generated 75 results on hangover and cognition (and synonyms) since the last published review. However, of these, only 4 met all inclusion criteria, such as establishing that BAL (Blood Alcohol Level) was zero at testing. Taking the findings of these newer studies with those that we reviewed previously, there appears to be real evidence of convergence of findings. There are now four rigorous laboratory studies, two less rigorous laboratory studies lacking placebo control and two rigorous naturalistic studies that indicate specific cognitive decrements in attention and memory during the hangover phase of alcohol consumption. Given this convergence, research agendas for increasing understanding of the cognitive effects of alcohol hangover should now switch from studies that routinely assess many cognitive functions to studies assessing the attention and memory deficits of hangover in greater detail.

Alcohol-induced hangover is commonly experienced after excessive alcohol consumption. This paper presents a critical review of literature on the next day effects of excessive alcohol consumption on subjective ratings of mood. The review has identified 7 comprehensive studies which have followed either the pharmacological approach or the naturalistic approach to investigating the mood state of the individual during the post intoxication hangover phase. There is diversity in the tools used to assess mood and in the aspects of mood measured, this needs to be addressed in future research however there is a general finding that mood is decreased during hangover.

Hangover may be related to propensity to develop alcohol use disorders (AUDs). However, the etiological role, if any, played by hangover in AUD is unclear. From a motivational perspective, hangover can be construed as either a deterrent to future alcohol consumption or a setting event for negative reinforcement that could promote deviant drinking practices (e.g., “hair-of-the-dog” drinking). Hangover could be related to AUD risk even if it does not play a direct role in promoting or inhibiting near-term drinking. For example, measures of hangover might serve as symptoms of AUD or as markers of individual differences that more directly account for AUD risk. Empirical evidence (though usually indirect) exists to support contentions that hangover is related to both risk for and protection from AUD. In this article, we briefly address variation in assessment strategies in existing hangover research because measures of hangover frequency and hangover susceptibility may prove to have different correlates. Next, we review the existing, limited evidence on relations between hangover and AUD risk. Finally, we sketch a variety of theoretically-informed hypotheses that might help delineate productive lines of inquiry for this emerging field.

The search for alcohol hangover cures is as old as alcohol itself. Many cures and prophylactic agents are available, but scientific evidence for their effectiveness is generally lacking. This review summarizes and discusses the limited number of studies that examined the effectiveness of alcohol hangover treatments. From these studies it must be concluded that most remedies do not significantly reduce overall hangover severity. Some compounds reduce specific symptoms such as vomiting and headache, but are not effective in reducing other common hangover symptoms such as drowsiness and fatigue. Hangover cures that showed positive effects were those inhibiting prostaglandin synthesis or accelerating alcohol metabolism. Future studies should elucidate the pathology of alcohol hangover. Until then, it is unlikely that an effective hangover cure will be developed.

Despite the high prevalence and economic burden, biological mechanisms and effective treatments of alcohol hangover are not well understood. We have focused on oxidative stress and inflammatory responses which would substantially contribute to hangover physiology and symptoms based on preexisting research data. And, it is considered that minerals are one of the important components and influencing factors in antioxidant and anti-inflammatory system. Moreover, mineral deficient conditions show similar symptoms that occur in alcohol hangover. Herein we review some possible implications of various minerals, such as selenium, zinc, copper, vanadium, iron, and magnesium, according to suggested mechanisms and symptoms of alcohol hangover. Although, noticeable considerations and controlled trials will be required for general recommendations, we hope that our preliminary speculation would pave the way for further understanding and managing alcohol hangover.

Alcohol-induced hangover, defined by a series of symptoms, is the most commonly reported consequence of excessive alcohol consumption. Alcohol hangovers contribute to workplace absenteeism, impaired job performance, reduced productivity, poor academic achievement, and may compromise potentially dangerous daily activities such as driving a car or operating heavy machinery. These socioeconomic consequences and health risks of alcohol hangover are much higher when compared to various common diseases and other health risk factors. Nevertheless, unlike alcohol intoxication the hangover has received very little scientific attention and studies have often yielded inconclusive results. Systematic research is important to increase our knowledge on alcohol hangover and its consequences. This consensus paper of the Alcohol Hangover Research Group discusses methodological issues that should be taken into account when performing future alcohol hangover research. Future research should aim to (1) further determine the pathology of alcohol hangover, (2) examine the role of genetics, (3) determine the economic costs of alcohol hangover, (4) examine sex and age differences, (5) develop common research tools and methodologies to study hangover effects, (6) focus on factor that aggravate hangover severity (e.g., congeners), and (7) develop effective hangover remedies.