No. If there was, frontline ENT journals would be falling over themselves to publish such research, and Indian biotech companies would be selling a drug developed from this. Drugs are more likely to cause tinnitus than cure it.
This is a fact that nutritional and herbal approaches are never encouraged to treat or manage mental illnesses. Saying that lack of popularity of such treatments is the reason that such treatments are not effective is a gross neglect of the actual condition. Western medicine has never given much importance to any traditional approach available in any culture. Otherwise they would have directly looked for solutions in eastern traditions which claim to have cures to several illnesses. Instead they have always looked for popularizing laboratory-based, allopathic cures.
Psychotherapy culture started with psychoanalysis and progressed over a century to find meditation based practices beneficial. The reason for such lack of evidence in Ayurveda or in related practices for cures of mental illnesses is the lack of initiative given by the cultures of which such practices are a part. Like, India should have focused, at least in part, on promoting evidence-based researches on effectiveness of ayurvedic medicine. But unfortunately this has never been done on large scale. We can not assume that western science, medicine in particular, is all-aware of all the possibilities in treating illnesses. There is a huge neglect by scientific community about approaches that can provide more scope in treatments of mental illnesses. Nutrition is one such important area. And medicinal herbs is yet another one.
For prevention of all physical diseases, there is one or more nutritional supplement with empirical evidence of its effectiveness. But what about mental illnesses? How many psychiatrists prescribe that such and such vitamin or protein should be taken or not taken in order to prevent the further worsening of a particular mental illness?? Since there is no such research, so there is lack of evidence, and hence lack of awareness that such treatments can be effective.
I believe that we need to base more research on testing the effectiveness of ayurvedic medicines in treating mental illnesses, than bluntly asserting that there is no cure because there are no researches in reputed, high impact factor journals.
" Western medicine has never given much importance to any traditional approach available in any culture"
Not so, see Wikipedia:
" In fact, according to the World Health Organisation, approximately 25% of modern drugs used in the United States have been derived from plants. Among the 120 active compounds currently isolated from the higher plants and widely used in modern medicine today, 80 percent show a positive correlation between their modern therapeutic use and the traditional use of the plants from which they are derived. At least 7,000 medical compounds in the modern pharmacopoeia are derived from plants"
Examples include aspirin, artemisinin, digitalis, morphine, quinine, rauwolfia, etc. Leeches and maggots still have a use.
This answer can certainly not be answered in a discussion like this.Looking at the properties of Ashwagandha I think it should work but i doubt if the same drug or prescription can benefit all the patients.
Ayurveda is an personalized system of medicine and one need to approach an experienced Ayurveda physician to do proper case analysis and then plan the treatment.There are several cases of various Idiopathic diseases getting relief from Ayurveda medicines but they are not reported properly.Moreover the results are not reproducible always.This is the mystery in this science which needs to be explored properly.
One can not always reject an fact or Phenomenon if there are no published scientific studies.In Practical life we accept many things even though we don't know the cause behind that phenomenon .In this case, when we say Idiopathic we mean the cause is not know but the disease still exist and it is an well accepted fact.In the same way Ayurveda works but there lacks proper Documentation.
When dealing with Holistic system of medicine ; we need to be more open minded and understand that the conventional RCT approach is not always suitable for analysis of an Holistic system .RCT approach was developed basically to facilitate New Drug development and this can not always help research in Holistic medicine.Holistic system of healing needs Pragmatic approach and probably we need to devise proper validated tools and methodology to explore such healing science. Many researchers are working in this direction and hopefully in future we may have answers and high level evidence to all the phenomenons seen in Ayurveda (and such similar science).