Repeated treatment with reserpine as a progressive animal model of depression.

Treatment-resistant depression is a major health problem worldwide. Restricted validity of the existing animal models of depression along with the need for the study of progressive development of resistance to antidepressants, demands the modeling of a progressive animal model of depression. Present study was designed to test the hypothesis that the repeated administration of reserpine could serve as a progressive animal model of depression. Animals were injected with reserpine (1.0mg/kg; once a day) for three weeks. Results from the present study showed impaired locomotive effects of reserpine in Skinner's box following second as well as third week. These hypolocomotive effects were more pronounced after third week than the second week. Reserpine-induced behavioral depression was evident in the animals after 2 weeks, as assessed by using forced swim test. Depletion of 5-HT, dopamine and metabolites was also observed in the brain samples. Results from the present study suggest that repeated administration of reserpine could be serve as a progressive model of depression and could be used as a convenient and economic animal model for the face validity of anxiolytic compounds. Findings have potential implications with reference to the understanding and the management of treatment-resistant depression.