Attenuation of sucrose consumption in mice by chronic mild stress and its restoration by imipramine.

Chronic exposure to mild unpredictable stressors (CMS) has previously been found to reduce the consumption of palatable, sweet solutions in rats. In the present study, the utility of this procedure was assessed in mice. Male AP mice subjected to CMS showed reduced consumption of a 2% or 4% sucrose solution. This effect was reversed by chronic (3 weeks) treatment with the tricyclic antidepressant imipramine (20 mg/kg per day). These results extend previous reports of a generalized decrease in sensitivity to reward (anhedonia) in rats caused by CMS and the efficacy of antidepressant treatment in this paradigm. Chronic unpredictable mild stress in mice appears to provide a realistic animal model of depression.