Ethanol Intake Under Social Circumstances or Alone in S prague– D awley Rats: Impact of Age, Sex, Social Activity, and Social Anxiety‐Like Behavior

Background In human adolescents, heavy drinking is often predicted by high sociability in males and high social anxiety in females. This study assessed the impact of baseline levels of social activity and social anxiety‐like behavior in group‐housed adolescent and adult male and female S prague– D awley rats on ethanol ( E t OH ) intake when drinking alone or in a social group. Methods Social activity and anxiety‐like behavior initially were assessed in a modified social interaction test, followed by 6 drinking sessions that occurred every other day in animals given ad libitum food and water. Sessions consisted of 30‐minute access to 10% E t OH in a “supersac” (3% sucrose + 0.1% saccharin) solution given alone as well as in groups of 5 same‐sex littermates, with order of the alternating session types counterbalanced across animals. Results Adolescent males and adults of both sexes overall consumed more E t OH under social than alone circumstances, whereas adolescent females ingested more E t OH when alone. Highly socially active adolescent males demonstrated elevated levels of E t OH intake relative to their low and medium socially active counterparts when drinking in groups, but not when tested alone. Adolescent females with high levels of social anxiety‐like behavior demonstrated the highest E t OH intake under social, but not alone circumstances. Among adults, baseline levels of social anxiety‐like behavior did not contribute to individual differences in E t OH intake in either sex. Conclusions The results clearly demonstrate that in adolescent rats, but not their adult counterparts, responsiveness to a social peer predicts E t OH intake in a social setting—circumstances under which drinking typically occurs in human adolescents. High levels of social activity in males and high levels of social anxiety‐like behavior in females were associated with elevated social drinking, suggesting that males ingest E t OH for its socially enhancing properties, whereas females ingest E t OH for its socially anxiolytic effects.