Alcohol Hangover and Risk of Drinking Problems and Alcohol Use Disorder: A Systematic Review

Introduction: Despite its high frequency, hangovers have received little systematic attention in the field of alcohol research, even though alcohol hangover contributes to a large number of socioeconomic consequences as well as health risks. Alcohol-induced hangover is a complex syndrome defined by a spectrum of symptoms. Not all drinkers experience hangovers, indicating individual alcohol tolerance. It is unknown whether frequently experiencing hangovers predicts the risk of problem drinking and alcohol use disorder. Methods: PubMed, EMBASE, PsycINFO, CINAHL, Web of Science, The Cochrane Library, Forskningsdatabasen.dk, Christin.no and Google were searched from January 1970 through August 2016 using combinations of search terms i.e., alcohol, alcohol dependence and hangover, and several other specific terms. All studies were conducted on human subjects, without restriction on participant demographics. Studies that investigated the association between experiencing hangover and alcohol use disorder were included. Two authors independently screened all papers, extracted study characteristics and assessed the quality by applying the Newcastle-Ottawa Scale. Results: Of 743 identified studies, only 4 met inclusion criteria. Studies were heterogeneous in multiple ways and the quality varied; two high-quality studies were identified. Results from three out of four studies indicated higher risk of problem drinking among individuals who experienced hangover compared to individuals who did not, adjusted for drinking habits. Conclusions: High-quality studies indicated an association of developing alcohol use disorder when frequently experiencing hangovers, adjusted for alcohol intake. This systematic review shows that the existing research is very sparse; hence further alcohol research in this area is much needed to increase our knowledge on alcohol hangover and its consequences.