Does it work and does it last? Effects of social and drinking behavior on same- and next-day mood.

Both social and drinking behavior have the potential to modify mood. However, if social drinking enhances positive mood and reduces negative mood, as compared to non-drinking social behavior, then interventions to reinforce non-drinking via sober social activity are undermined. Using multilevel modeling analyses, we compared end-of-day mood on drinking days versus non-drinking days, and on days spent with other people as compared to days spent primarily alone. We evaluated the interaction between drinking/non-drinking and social/solitary behavior and assessed whether the effects of social and drinking behavior extended to mood the next day. Participants were 352 college students (53% female; 55% fraternity/sorority membership; mean age 19.7 years) who completed three automated telephone surveys each day during four 14-day intervals over 1 year. Drinking and being social were associated with higher end-of-day positive mood and significantly lower end-of-day negative mood. However, no positive enhancement or negative attenuation effects of alcohol were observed in interaction analyses. Alcohol provided no improvement in mood over-and-above being social at the end of the day or on the following day. However, drinking the previous day significantly reduced next-day positive mood, whereas being social significantly reduced next-day negative mood. These findings provide support for the reinforcing potential of interventions that increase rewarding social activity in the place of alcohol use.