For adolescent rats, drugs are better with company, and vice versa. Given the opportunity to spend time in two cage compartments, young rats preferred the one in which they'd twice visited with a peer and also received a low dose of either nicotine or cocaine over the compartment that had furnished neither companionship nor a drug. In contrast, they showed no such partiality for a compartment in which they had previously received only companionship or only the low dose of drug.
Dosage mattered: Rats did gravitate to compartments where they had experienced either a higher dose of drug or more than two previous social opportunities. Dr. Janet Neisewander, graduate student Kenneth Thiel, and colleagues at Arizona State University say that their findings emphasize the importance of examining drug reward in a social context. Animal protocols that include peer contact may more closely mimic early stages of drug abuse, which typically occurs in a group setting.
Psychopharmacology 204(3):391-402, 2009. [Full Text (PDF, 225KB)]
Drug and Alcohol Dependence 96(3):202-212, 2008. [Full Text (PDF, 442KB)]