STUDY: Kasper S et al, Eur Arch Psychiatry Clin Neurosci 2024
STUDY TYPE: Randomized, double-blind, placebo- and reference-controlled trial
EVIDENCE GRADE: High (10/10)
FUNDING: Dr. Willmar Schwabe GmbH & Co. KG (manufacturer of Silexan)
Background
In many countries, herbal medicines are regulated much like industrial medications, but not in the US. One of the more effective crops is Silexan, a patented extract of lavender oil that treats anxiety with a large effect size (0.7-0.9) and surpassed an SSRI antidepressant in a large, randomized trial of generalized anxiety disorder. In earlier trials, lavender treated anxious depression, and this is the first trial to test it in pure depression.
The Study
498 adults with mild-to-moderate major depression were randomized to Silexan 80 mg/day, sertraline 50 mg/day, or placebo for 8 weeks. The primary outcome was change on the Depression scale (MADRS).
Both Silexan and sertraline beat placebo on MADRS scores (differences of 2.2 and 2.6 points, respectively), with response rates of 54% and 54% versus 42% for placebo (NNT = 9 and 8). Remission rates followed the same pattern: 44% and 45% versus 33%. The effect sizes are modest — squarely in the range of standard antidepressants in mild-to-moderate depression. One surprise: Silexan outperformed sertraline on functional impairment (Sheehan Disability Scale), improving work, social life, and family functioning. Sertraline did not. The main side effect of Silexan was burping (17% of patients) — annoying but harmless.
Notably, this study used 80 mg, while most anxiety trials used 160 mg.
Practice Implications
- Lavender likely works in mild-moderate depression, though it is much better studied in anxiety.
- Herbs have problems with manufacturing quality, but this one is produced by a regulated manufacturer in Germany. Although it is available by prescription there, in the US the same manufacturer sells it over the counter as CalmAid.
—Chris Aiken, MD
Director, Psych Partners
Editor in Chief, Carlat Psychiatry Report
What’s Your Take? Share in Comments
- Have you seen antidepressant effects with lavender, or just anti-anxiety?
