Kikuchi A., Oshima M., Namiki T., Suzuki H., Kojima M. Effects of Hericium erinaceus on depressive and anxiety symptoms in adults with subthreshold manifestations: A randomized, double-blind, placebo-controlled trial. Journal of Affective Disorders Reports. 2023;14:100544.
Rationale
Beyond cognition, lion's mane is marketed for mood — a claim resting on a handful of small studies (Nagano 2010 in menopausal women being the classic). This 2023 RCT tested a standardized extract in adults with clinically relevant but mild-to-moderate depressive and anxiety symptoms.
Methods
A randomized double-blind placebo-controlled parallel-group trial: 77 adults with BDI-II ≥ 10 and GAD-7 ≥ 5 took 3 g/day of a standardized H. erinaceus fruiting-body extract or placebo for 8 weeks. Outcomes: BDI-II depression inventory, GAD-7 anxiety scale, PSQI sleep quality, safety labs.
Results
The active group improved significantly versus placebo on all three symptom measures: BDI-II down 31%, GAD-7 down 33%, PSQI sleep quality up 26%. The BDI-II effect size (d ≈ 0.62) is moderate — clinically noticeable, not dramatic. Side-effect rates matched placebo.
Conclusions
Standardized lion's mane extract meaningfully reduced depressive and anxiety symptoms over 8 weeks in this population — the strongest mood-domain datapoint for the species to date.
Worth noting
n=77 and a real effect size make this more substantive than the earlier n=30 work. Still a single trial in a defined symptom band; replication and longer follow-up would consolidate it. The practical caveat: participants had diagnosed symptom elevations — transfer to healthy people seeking a "mood boost" is speculative.