A preliminary randomized double blind clinical trial on the efficacy of aqueous extract of Echium amoenum in the treatment of mild to moderate major depression

Background: Based on a traditional belief, Echium amoenum (Boraginaceae) dried flowers are used in Iran as an anxiolytic remedy and also as a mood enhancer. In this study, efficacy of an aqueous extract of E. amoenum in patients with mild to moderate major depressive disorder (a score >= 18 on the Hamilton depression rating scale) was evaluated. Methods: 35 patients were randomly assigned to receive daily either placebo or 375 m of E. amoenum aqueous extract in a 6-week double blind, parallel-group trial. Patients were assessed in weeks 0, 1, 2, 4 and 6 by the Hamilton Rating Scale for Depression (HAM-D-17) the Hamilton Rating Scale for Anxiety (HAM-A(14)), and a score sheet on adverse effects. Results: In week 4, the extract showed a significant superiority over placebo in reducing depressive symptoms. The effect on anxiety was not significant. Headache, somnolence, vomiting, dry mouth, constipation and blurred vision are the most commonly reported side effects. However, with regards to these side effects, no significant difference between placebo and drug treated groups was observed. Limitations: This study is performed with a small sample size, only with one dose and for 6 weeks. Conclusion: E. amoenum aqueous extract may have some antidepressant activity. (c) 2005 Elsevier Inc. All rights reserved.