Background/Objectives: Echinacea extracts with unique alkamide profiles (EP107™) have
been shown to affect upper respiratory tract infections and reduce anxiety in both
animals and humans. However, a recent study found that a similar extract did not reduce
anxiety more than a placebo, although it did enhance well-being and produced antidepressant-like
effects. We hypothesized that the discrepancy arose from the differences in the anxiety
assessment methods used. The study that observed no effects used the Clinically Useful
Anxiety Outcome Scale, which focuses on physical symptoms, while earlier studies used
the State-Trait Anxiety Inventory, which focuses on psychic symptoms. Methods: To
investigate the influence of the anxiety measure on the detectability of anxiolytic
effects, we examined the effects of Echinacea EP107TM using the Hospital Anxiety and
Depression Scale–anxiety subscale (HADS-A), which focuses on psychic symptoms, and
the Hamilton Anxiety Rating Scale (HAM-A), most items of which involve physical symptoms.
The study was placebo-controlled, double-blind, and multicenter. Results: The extract
significantly alleviated anxiety compared to placebo when measured with HADS-A. HAM-A
total scores did not show significant treatment effects. However, Echinacea was superior
to placebo in three psychic anxiety items on the HAM-A. Conclusions: These findings
suggest that Echinacea EP107TM reduces psychic anxiety without affecting somatic symptoms.
This indicates that the extract may be useful in mild or early-phase anxiety when
somatic symptoms are not prominent.
