Introduction: Major depressive disorder is a chronic disease which may be associated with other mental illnesses. Lavandula officinalis and venlafaxine, herbal and chemical drugs respectively, are used to treat depression. Despite pharmacotherapy, major depressive disorder has a complicated pattern of resistance and recurrence.
Aim: The aim of this study was to determine the effect of L. officinalis and venlafaxine in treating depression.
Materials and methods: For this study, 120 patients referred to the psychiatry clinic of the Shahrekord University of Medical Sciences, Shahrekord, Iran, were randomly selected. The participants were randomly assigned to three groups: venlafaxine (Control Group), venlafaxine + L. officinalis (L. officinalis Group), and venlafaxine + placebo (Placebo Group). All the patients underwent treatment for six weeks. Depression test was administered to the three groups at different time intervals before the treatment, four weeks after the treatment and at completion of the treatment. The data were analysed by SPSS version17.0.
Results: Depression scores of all the groups decreased over time (p=0.001). The depression scores were significantly different between the control and L. officinalis groups (p=0.004), and the control and placebo groups (p=0.002), but were not significantly different between the L. officinalis and placebo groups (p=0.95).
Conclusion: Adding L. officinalis or a placebo is equally effective in decreasing mean depression score and venlafaxine obviously decreased this score.
Keywords: Antidepressant; Depressive disorder; Medicinal plant.