Baer, H. 1971. Long-term isolation stress and its effects on drug response in rodents. Laboratory Animal Science 21, 341-349.

This review of the literature has illustrated that isolation stress, especially long-term isolation stress in rats and mice, can affect the growth, behavior, physiological condition, and response to a wide variety of drugs. ... Isolation stress in mice produces abnormal behavior (such as aggressiveness, excitability, and nervousness); changes in body weight; and organ weights; blood changes (leukopenia, eosinopenia); and frequently increased adrenal function over that of community housed mice.