I don't know about any large samples, but there is a chapter on using Mudras to manage moods in Yoga skills for therapists: Effective practices for mood management.
Weintraub, Amy. New York, NY, US: W W Norton 2012). x 225 pp.
Here is my book about applying the Chakras in the clinical setting. Hope this helps! https://www.amazon.com/Innate-Design-Melissa-Aguirre/dp/1504360028
Published articles may mean nothing if they are methodologically defective. In Medicine the greater credibility is based on systematic reviews of randomized and controlled clinical trials published in databases of high credibility by the scientific community. This is the only way we can get rid of pseudo-scientific interventions in vain of metaphysical influences.