Abstract
BACKGROUND: Solitary alcohol use among young adults is a risky drinking behavior associated with concurrent and future alcohol use disorder (AUD) and negative psychosocial outcomes. However, data on its prevalence and historical trends in the general population are limited. We examined historical trends in solitary alcohol use among US young adults (aged 19-30) by age and sex over a 46-year period. METHODS: Data were from the Monitoring the Future (MTF) Panel study collected between 1977 and 2022. The sample included 12,851 participants (51.6% female) who reported past-year alcohol use and completed surveys at ages 19/20, 21/22, 23/24, 25/26, 27/28, and 29/30. Solitary alcohol use was assessed by self-report of drinking alone in the past year. Joinpoint regression analyses examined historical trends in the prevalence of solitary alcohol use by age and sex. RESULTS: Approximately 40% of those who used alcohol in the past year reported engaging in solitary alcohol use at least once in the past year. Across all age groups, the prevalence of past-year solitary alcohol use initially decreased and then increased over time. Significant joinpoints indicated shifts in trends beginning in the mid-1990s to early 2000s, with increases more pronounced among females. CONCLUSIONS: The prevalence of solitary alcohol use among US young adults has increased in recent decades, to levels on par with what was observed in the late 1970s. Particular increases among females since late 1990s/early 2000s have narrowed the traditional sex gap in this risky drinking behavior. Given the association of solitary drinking with concurrent and future alcohol problems, these findings highlight the need for continued monitoring of solitary alcohol use among young adults, especially females.