Alcohol hangover: a critical review of explanatory factors.
OBJECTIVE
To describe the hangover phenomenon and briefly review its main explanatory factors.


METHODS
Bibliographic research on main databases (Medline and Psychinfo).


RESULTS
Alcohol hangover is characterized by adverse physical and mental effects that occur the next morning after the intake of toxic doses of alcohol. This phenomenon is a very frequent experience among alcohol-consuming people and it has been associated to high socio-economic costs, mainly due to absenteeism and poor performance in academic and work settings. Multiple theories exist to explain the appearance and severity of hangover, such as direct or indirect effects of alcohol, alcohol withdrawal, and toxic effects of alcoholic beverage congeners or of alcohol metabolites. In addition, a number of intervening factors have been identified, such as vulnerability to alcohol dependence or psychological factors.


CONCLUSIONS
Although several studies analyze and describe hangover, it is still poorly understood. Further well-designed studies with a unitary methodology and clear operational criteria to define hangover are necessary in order to clarify such a phenomenon. We suggest some future working ideas that should be pursued in order to address the current shortcomings.
Prat
Gemma
G
Department of Psychiatry and Clinical Psychobiology, School of Psychology, University of Barcelona, Barcelona, Spain. gprat@ub.edu
Adan
Ana
A
Sánchez-Turet
Miquel
M
D000428:Alcohol Drinking / Q000009:adverse effects* / Q000523:psychology*; D002492:Central Nervous System Depressants / Q000009:adverse effects*; D000431:Ethanol / Q000009:adverse effects*; D006801:Humans; D019966:Substance-Related Disorders / Q000150:complications
D002492:Central Nervous System Depressants; D000431:Ethanol