There is a new mental disorder called "Money Hoarding", and I am being serious. Please look up and observe animal hoarders, junk, etc. They are addicted and cannot stop themselves even if they wanted to.
An animal hoarder will collect 50 to 100 dogs, cats, etc. and will not be able to let one single animal leave. They will continue to collect more and more animals for reasons only they can rationalize. The problem is that they cannot take care of all the animals and themselves, all suffer. Junk hoarders are the exact same, just with a different medium. Drug addicts are another, just with a different medium, and chemical effects.
Cash or money hoarders will collect large sums of money for no real reason. They will cause people around them to suffer because of their addiction. They cannot stop themselves from collecting more and more. I would say that qualifies as a hoarder and the medical field has not been diagnosing this addiction or disorder.
We just need to help our fellow humans out with their disorder/addiction. Philanthropy is another cure for this disorder. I would like to see everyone with over a certain amount of money checked for this disorder. I bet we would find quite a few with it.