The reason I suggested confirming the mental issues was because from your post they already have an idea that it is going on so no doubt are gossiping about it already,

Only thing is they are making it up as they really don’t have the facts. I am in no way suggesting that you hold a meeting in the workplace announcing it to everyone, however if you could speak with a college who you are a little closer too regarding the problem, the hope is that this would then circulate in the gossip breaks and let them know the truth, also it will hopefully stop the gossip as there would no longer be anything to gossip about.