The effect of docosahexaenoic acid (DHA) supplementation on experimental depression in mice

Background: Depressive disorder is a prevalent psychiatric disorder, which affects 21% of the world population. Many drugs which are available as effective antidepressants produce various side effects like sedation weight gain postural hypotension etc., so there is need to develop novel compounds with minimized side effects. Hence this study was aimed to investigate the antidepressant activity of DHA, an omega-3 polyunsaturated fatty acid in albino mice.Methods: Animals were divided into four groups, consisting six mice in each group. Out of these, group I served as control (2% gum acacia), group II and III received test drug in two different doses 200mg/kg and 300mg/kg respectively and group IV received fluoxetine (20mg/kg) as standard drug. To determine the antidepressant-like activity, we used forced swim test and tail suspension test in mice. These methods are based on the observation that a mouse show alternating agitation and immobility; the immobility is indicative of a state of depression.Results: DHA produced significant antidepressant effect at all the doses, as indicated by reduction in immobility times as compared to control in both FST and TST. (P˂0.05) The efficacy of DHA at dose of 300 mg/kg was comparable with that of fluoxetine. DHA at 200mg/kg dose showed significantly less antidepressant activity compared to fluoxetine. (P˂0.05).Conclusions: The result specifies that compared to two doses of DHA (200mg/kg and 300mg/kg), higher dose of DHA found as an effective dose for treating depression produced due to stress