American Skullcap (Scutellaria lateriflora ): A Randomised, Double-Blind Placebo-Controlled Crossover Study of its Effects on Mood in Healthy Volunteers

Abstract

Scutellaria lateriflora, a traditional herbal remedy for stress and anxiety, was tested on human volunteers for its effects on mood. In a placebo-controlled, double-blind, crossover study, 43 healthy participants were randomised to a sequence of three times daily S. lateriflora (350 mg) or placebo, each over two weeks. In this relatively non-anxious population (81% were mildly anxious or less, i.e. Beck Anxiety Inventory (BAI) scores ≤ 15), there was no significant difference between skullcap and placebo with BAI (p = 0.191). However, there was a significant group effect (p = 0.049), suggesting a carryover effect of skullcap. For Total Mood Disturbance measured by the Profile of Mood States, there was a highly significant (p = <0.001) decrease from pre-test scores with skullcap but not placebo (p = 0.072). The limitations of carryover effect, generally low anxiety scores and differences in anxiety levels between groups at baseline (p = 0.022), may have reduced the chances of statistical significance in this study. However, as S. lateriflora significantly enhanced global mood without a reduction in energy or cognition, further study assessing its putative anxiolytic effects in notably anxious subjects with co-morbid depression is warranted.

Herbal medicine for depression and anxiety:Asystematic review with assessment of potential psycho‐oncologic relevance

“…American skullcap ( Scutellaria lateriflora ) has been compared with stinging nettle leaf ( Urtica dioica folia ) for its effects on improving mood in healthy participants (Brock, Whitehouse, Tewfik, & Towell, ). No significant differences were found, but this may be due to low levels of anxiety at baseline.…”

Herbal medicines in the treatment of psychiatric disorders: 10‐year updated review

“…Two human studies using scullcap extract were found, both in nonclinical samples. In a double‐blind crossover RCT ( n = 43) in which participants were initially randomized into either 2 weeks of 350 mg of scullcap extract (3 times per day) or a placebo comparator, Brock, Whitehouse, Tewfik, and Towell () reported no difference in anxiety outcomes between groups. This was ascribed to both a “floor effect,” as these healthy volunteers were mostly non‐anxious at baseline, as well as baseline heterogeneity between groups.…”

Herbal Medicine for Insomnia

“…It has been shown to have a mild anxiolytic effect in healthy, mildly anxious adults. 57 It is an herb with a very strong tradition as a mild improver of sleep quality however, and should be considered right alongside the other herbs discussed here. It has a bitter quality and so may be most appropriate for patients who also have atonic digestive tracts.…”