A scoping review of Dry January: evidence and future directions.

Dry January is a temporary alcohol abstinence challenge where participants commit to abstaining from drinking alcohol for one month. It has grown in popularity since its inception >10 years ago. The current scoping review sought to broadly characterize the peer-reviewed literature on Dry January, summarize its main findings, strengths and limitations, and delineate future research directions. In total, 90 publications were screened and 16 were reviewed. Findings revealed that compared to drinkers in the general population who did not participate, Dry January participants tended to report having higher incomes, completed university education, reported being female, younger, and engaging in heavy drinking at baseline. Those who consumed light to moderate amounts of alcohol were more likely to report successfully abstaining than heavier drinkers. Among successful abstainers, short- and mid-term sustained reductions in self-reported alcohol use and improved biological outcomes, well-being, and drink refusal self-efficacy were observed. Benefits were also reported among those who did not fully abstain. Most Dry January participants would participate in the program again. Overall, Dry January demonstrates significant promise and warrants more rigorous research. As nearly all extant research derives from the United Kingdom, future research should investigate applications and effects beyond that population.