Medical plants have been used for centuries as a medicinal agent in treatment of depression and anxiety. The purpose of this study was to explore the effects of the lavendula officinalis on depression in patients using citalopram.

This clinical trial study was performed in Hajar hospital, Shahrekord, Iran. In this study eighty patients randomly allocated into two groups (40 patients in each group). Patients who complained from depression were studied during a two-month double-blind study. In control group, patients were given 20 mg citalopram twice daily plus placebo and case group were treated with 5 g arial part of dried Lavendula officinalis and citaloperam (20 mg, twice per day). After 4 and 8 weeks, patients were followed for evaluations of their depression and complications. Depression severity was scored using standard Hamilton’s depression questionnaire. Data were analyzed using Chi square and Paired-t test.

After 1 month treatment, mean depression score in case and control groups were 15.2 ± 3.6 and 17.5 ± 3.5, respectively (P < 0.05). After 2 months the mean score of depression in case and control groups was 14.8 ± 4 and 16.8 ± 4.6, respectively (P < 0.01). The most common side effects in two groups were confusion and dry mouth, which were not significantly different between two groups.

Lavendula officinalis has a positive effect on depressed patients and may be useful to decrease the severity of depression in patients using other antidepressants.