Evaluation of antidepressant action of nicotine in an animal model

Introduction: Nicotine may have antidepressant properties and smokers self-medicate underlying depression. Epidemiological findings suggest that smokers more often demonstrate depressive symptoms than non-smokers and depressed patients are less likely to cease smoking. Aim & Objectives: To evaluate the effect of nicotine given as acute and chronic combination therapy with imipramine in learned helplessness model in rats.
Material and Methods: Learned helplessness model is a standard model for evaluation of antidepressant drugs. The statistical significance was determined by ANOVA followed by Tukey test (p<0.05).
Results: In this model, results were expressed as percentage of animals showing presence of escape response. Combination therapy of imipramine (i.p.) with nicotine (s.c.) given for 7 days produced significant antidepressant action as compared to combination therapy of imipramine (i.p.) given for 7 days with single dose of nicotine (s.c.).
Conclusion: It was observed that combination dose of imipramine with nicotine given for 7 consecutive days significantly exhibited antidepressant action by increasing percentage of escape response.