Length of social deprivation differently affects free-choice morphine consumption in C57BL/6J mice

The effects of social deprivation on morphine consumption in C57BL/6J mice were investigated. Social or isolated animals (length of isolation: 7, 12, 17 days) were submitted to a free-choice between water and morphine hydrochloride solution (0.5 mg/ml). Isolation affects morphine consumption, with solitary housed mice drinking more morphine solution than socially housed animals. Moreover the amount of morphine intake depends on the duration of the isolation period to which mice are subjected. The importance of environmental factors on opiate consumption may be considered in terms of the possible implications of drug addiction in humans.