Very important study, and yet small N, no control group, and expectancy effect may be at work, yet this is a very promising study and worth others following up on and Long COVID clinics to explore. There is precious little to help the many who have been seriously struggling with little or no support. Yes many unknowns but not enough time, financial support or media attention given to the serious suffering of so many. We can do better and we should do better. Any further studies on Naltrexone, please let us know and if any other tx for ME/CFS and POTS please keep us posted. Those with Long COVID illness are effecting their own mental health, by not being heard and helped, or given priority, and it is effecting their families, their employment, our economy and in extreme ways their own mental health and that are so many others. Add to this the facts, that there are more females, and those in 40-65 range and we may have outdated sexism going on - this needs to be addressed. Thank you to the Mayo Clinic! Diane Bridgeman, Ph.D.