Solitary drinking is a risk marker for alcohol use disorder; thus, it is important to identify why individuals drink alone and for whom this association is particularly relevant. Evidence suggests the desire to ameliorate negative affect (NA) motivates solitary drinking, with some individuals particularly likely to drink alone to cope, but all past studies are cross-sectional. The present study therefore aimed to determine whether 1) experimentally induced NA increased preferences to drink alcohol alone, and 2) whether the relationship between NA and choosing to drink alcohol alone was moderated by neuroticism, drinking to cope motives, and social anxiety. Current drinkers (ages 21-29) with a solitary drinking history (N=126) were randomly assigned to either NA, positive affect [PA], or no affect change (control) conditions via differing cognitive task feedback. After the mood manipulation, participants chose between drinking alcoholic or nonalcoholic beverages in one of two contexts: alone or socially. Evidence regarding effectiveness of the mood manipulation was mixed, and few chose non-alcoholic beverages in either context. Condition did not influence outcome choice. Across conditions, increases in NA and the importance placed on receiving one’s context choice were associated with solitary (versus social) alcohol preference. Neuroticism and its interaction with NA change also influenced choice; individuals high in neuroticism chose more solitary (versus social) drinking contexts while the opposite was true for those low in neuroticism, and among the latter, the preference difference was more pronounced with relatively smaller NA increases. Findings are discussed based on the existing solitary drinking literature.