The importance of targeting sleep in the prevention and treatment of psychological disorders.

Approximately 50% of young adults between 18 to 25y report drinking alcohol in the past month; and 29% of those report past-month binge drinking (, ). Heavy drinking increases risk of consequences from embarrassing oneself to alcohol-related injury or overdose, creating significant public health burden (). It has also been linked to alcohol-induced blackout, defined as permanent (“en bloc”) or temporary (“fragmentary”) memory loss as a result of drinking (, ). Blackouts are a consequence of notable concern because they are associated with other alcohol-related problems. For example, Hingson and colleagues () found young adults who experienced a blackout in the last six months were more likely than those who did not blackout to report physical injury, doing something they later regretted, and getting in legal trouble. Therefore, strategies that mitigate alcohol-related consequences are especially needed among young adults who experience blackouts. Protective behavioral strategies (PBS) are designed to minimize negative alcohol-related consequences (). They are typically grouped into three categories: limiting/stopping (e.g., setting a limit for number of drinks consumed, having a friend let you know when you’ve had enough), manner-of-drinking (e.g., avoiding shots or drinking games, drinking slowly rather than chugging), and serious harm reduction strategies (e.g., designating a sober driver, going home with a friend). Young adults who report frequent use of PBS tend to drink less and experience fewer negative alcohol-related consequences (–), including blackouts (). However, most studies focus on between- (versus within-) person differences. The field’s gradual shift in focus to within-person differences is consistent with psychological theories, the majority of which posit within-person processes (). In the case of PBS, we expect an individual to experience fewer consequences on days they use PBS (within-person effect). However, it is possible that the people who use PBS habitually drink less and experience fewer consequences than those who do not use PBS (between-person effect), in the absence of a within-person association. Micro-longitudinal research designs involving daily surveys allow for this disaggregation of within-from between-person variability (), while also reducing retrospective recall bias (). To date, only three studies have tested day-level associations between PBS and drinking outcomes (–). Focusing specifically on days of high-intensity drinking, Linden-Carmichael and colleagues () found college students were less likely to report negative consequences on days they used manner-of-drinking or serious harm reduction strategies, with more consistent evidence for manner-of-drinking strategies. In contrast, Merrill and colleagues () found use of limiting/stopping (but not manner-of-drinking or serious harm reduction) strategies was associated with lower likelihood of experiencing consequences. Adding to the nuance, Pearson and colleagues () found serious harm reduction strategies were positively associated with negative consequences – perhaps because serious harm reduction strategies are used on days young adults plan to engage in heavy drinking. For example, individuals may designate a driver because they intend to get too drunk to drive (). However, Pearson and colleagues also found manner-of-drinking strategies were associated with lower alcohol consumption (), supporting the idea that different types of PBS have different effects on consumption and consequences.