Alcohol Hangover Mechanisms and Mediators Robert Swift, M.D., Ph.D.; and Dena Davidson, Ph.D. Hangovers are a frequent, though unpleasant, experience among people who drink to intoxication. Despite the prevalence of hangovers, however, this condition is not well understood scientifically. Multiple possible contributors to the hangover state have been investigated, and researchers have produced evidence that alcohol can directly promote hangover symptoms through its effects on urine production, the gastrointestinal tract, blood sugar concentrations, sleep patterns, and biological rhythms. In addition, researchers postulate that effects related to alcohol’s absence after a drinking bout (i.e., withdrawal), alcohol metabolism, and other factors (e.g., biologically active, nonalcohol compounds in beverages; the use of other drugs; certain personality traits; and a family history of alcoholism) also may contribute to the hangover condition. Few of the treatments commonly described for hangover have undergone scientific evaluation. KEY WORDS: post AOD intoxication state; symptom; urinalysis; gastrointestinal disorder; hypoglycemia; sleep disorder; circadian rhythm; ethanol metabolite; disorder of fluid or electrolyte or acid-base balance; nutrient intake; headache; vomiting; neurotransmitter receptors; congenors; multiple drug use; personality trait; family AODU (alcohol and other drug use) history; drug therapy; literature review “My first return of sense or recol- he British writer William Hickey its aftereffects, or a combination of lection was upon waking in a wrote these words in the year both. Similarly, investigators are uncer- strange, dismal-looking room, my T1768, vividly describing the tain about the degree to which hangover head aching horridly, pains of a aftermath of a bout of heavy alcohol affects a person’s thinking and mentally violent nature in every limb, and drinking—an experience commonly controlled motor functions, a question deadly sickness at the stomach. referred to as a “hangover.” Similar with serious implications for activities From the latter I was in some descriptions of hangovers appear in the degree relieved by a very copious writings of ancient Egypt and Greece vomiting. Getting out of bed, I as well as in the Old Testament. No ROBERT SWIFT, M.D., PH.D., is associate looked out of the only window in doubt, prehistoric people also experi- professor in the Department of Psychiatry the room, but saw nothing but enced hangovers soon after they and Human Behavior at Brown Univer- the backs of old houses, from discovered alcohol. sity, Providence, Rhode Island, and which various miserable emblems Despite its long history, however, associate chief of staff for research and of poverty were displayed . At hangover has received relatively scant education at Providence Veterans that moment I do not believe in formal attention from researchers. Affairs Medical Center. the world there existed a more Little is known about the physiology wretched creature than myself. underlying the hangover condition. For DENA DAVIDSON, PH.D., is assistant I passed some moments in a example, it is unclear whether hangover professor of psychiatry at Indiana state little short of despair . .” signs and symptoms are attributable University of Medicine, Indianapolis, —William Hickey (Spenser 1913) to alcohol’s direct effects on the body, Indiana. 54 Alcohol Health & Research World Alcohol Hangover such as job performance and driving. toms include dizziness; a sense of the zero were tested following alcohol In addition, researchers know little room spinning (i.e., vertigo); and intoxication with peak BAC’s in the about hangover prevention and treat- possible cognitive and mood distur- range of 50 to 100 milligrams per ment. Although folk remedies for bances, especially depression, anxiety, deciliter (mg/dL), most of them did hangovers abound, their efficacy in and irritability. The particular set of not show significant impairments in reducing the intensity and duration symptoms experienced and their inten- the performance of simple mental of a hangover has not received system- sity may vary from person to person tasks, such as reaction time (Lemon et atic study. In fact, some researchers and from occasion to occasion. In al. 1993). Similarly, several studies and clinicians question whether finding addition, hangover characteristics may that investigated the hangover effects an effective treatment for hangovers depend on the type of alcoholic beverage on a more complex mental task (i.e., is desirable, given that the hangover consumed and the amount a person simulated automobile driving) did not experience may deter some people drinks. Typically, a hangover begins report impaired performance (Streufert from engaging in subsequent episodes within several hours after the cessation et al. 1995; Tornros and Laurell 1991). of heavy drinking. of drinking, when a person’s blood In contrast, a study of military pilots Although gaps clearly remain in alcohol concentration (BAC) is falling. completing a simulated flying task scientific knowledge about hangovers, Symptoms usually peak about the revealed significant decrements in research has elucidated several aspects. time BAC is zero and may continue some performance measures (particu- This article describes what is known for up to 24 hours thereafter. larly among older pilots) 8 to 14 hours about the hangover condition, the Overlap exists between hangover and after they had consumed enough alco- possible physiological factors contribut- the symptoms of mild alcohol with- hol to be considered legally drunk ing to it, and treatment options. drawal (AW), leading to the assertion (Yesavage and Leirer 1986). that hangover is a manifestation of mild withdrawal. Hangovers, how- What Is a Hangover? ever, may occur after a single bout of Prevalence of Hangover drinking, whereas withdrawal occurs A hangover is characterized by the usually after multiple, repeated bouts. Generally, the greater the amount constellation of unpleasant physical Other differences between hangover and duration of alcohol consumption, and mental symptoms that occur after and AW include a shorter period of the more prevalent is the hangover, a bout of heavy alcohol drinking (see impairment (i.e., hours for hangover although some people report experi- table 1). Physical symptoms of a versus several days for withdrawal) encing a hangover after drinking low hangover include fatigue, headache, and a lack of hallucinations and seizures levels of alcohol (i.e., one to three increased sensitivity to light and in hangover. alcoholic drinks), and some heavy sound, redness of the eyes, muscle People experiencing a hangover feel drinkers do not report experiencing aches, and thirst. Signs of increased ill and impaired. Although a hangover hangovers at all. A survey by Harburg sympathetic nervous system activity may impair task performance and and colleagues (1993) on the preva- can accompany a hangover, including thereby increase the risk of injury, lence of hangovers found that approx- increased systolic blood pressure, equivocal data exist on whether hang- imately 75 percent of the subjects rapid heartbeat (i.e., tachycardia), over actually impairs complex mental who drank to intoxication reported tremor, and sweating. Mental symp- tasks. When subjects with a BAC of experiencing a hangover at least some of the time. In a study of 2,160 Finnish men, researchers found an association Table 1 Symptoms of Hangover between increased weekly alcohol consumption and the frequency of Class of Symptoms Type hangover: 43.8 percent of the group of heaviest drinkers (i.e., study subjects Constitutional Fatigue, weakness, and thirst who drank more than 106 grams [g] Pain Headache and muscle aches of alcohol per week or approximately Gastrointestinal Nausea, vomiting, and stomach pain 9 drinks) reported experiencing a hang- Sleep and biological rhythms Decreased sleep, decreased REM,1 over monthly or more often, compared and increased slow-wave sleep with 6.6 percent of the remaining Sensory Vertigo and sensitivity to light and sound study subjects (Kauhanen et al. 1997). Cognitive Decreased attention and concentration Mood Depression, anxiety, and irritability Similarly, in a study of 1,041 drinkers Sympathetic hyperactivity Tremor, sweating, and increased pulse in New York State, 50 percent of the and systolic blood pressure subjects who drank two or more drinks per day reported experiencing hang- 1REM = rapid eye movements. overs in the previous year, whereas subjects who consumed lower levels Vol. 22, No. 1, 1998 55 of alcohol reported fewer hangovers hormone (i.e., antidiuretic hormone, these factors can result in the upper (Smith and Barnes 1983). Other reports, or vasopressin) from the pituitary gland. abdominal pain, nausea, and vomiting however, claim that hangovers occur In turn, reduced levels of antidiuretic experienced during a hangover. less often in heavy drinkers. In a study hormone prevent the kidneys from of 43 alcoholic drinkers admitted for reabsorbing (i.e., conserving) water Low Blood Sugar. Several alterations inpatient treatment, 50 percent of the and thereby increase urine production. in the metabolic state of the liver and subjects reported experiencing no hang- Additional mechanisms must be at other organs occur in response to the overs within the previous year and 23 work to increase urine production, presence of alcohol in the body and percent reported never experiencing a however, because antidiuretic hormone can result