Efficacy and tolerability of Lavandula angustifolia in treating patients with the diagnosis of depression: a systematic review of randomized controlled trials.

Pharmacotherapy is the conventional treatment for depression, with only half of the patients responding to the first trial of monotherapy with first-line medicines. One way to overcome this resistance is to use complementary and alternative medicine. The antidepressant effects of Lavandula angustifolia, which is commonly called lavender, have been investigated in previous studies. This study aims to provide the first systematic review of lavender in treating patients with depression diagnosis. ISI Web of Science, Scopus, PubMed, Embase, PsycINFO, Google Scholar, and three trial registries were searched until May 2020 to find randomized controlled trials on lavender for depressed patients. The primary outcome was difference between the intervention and control groups in changing depression scores from baseline to endpoint. The included studies were assessed for effect size and methodological quality. Seven clinical trials were identified, in which 852 patients were studied. In six trials, the effectiveness of lavender in treating depression was reported, as being more pronounced adjunct to a typical antidepressant in one study. Significant reported side effects include headaches and eructation. Lavender is beneficial, tolerable, and safe in treating depression. Despite obtaining promising results, they are not enough to recommend prescribing lavender to depressed patients. Further high-quality, large-scale studies for rectifying the shortcomings of existing studies are recommended.