I don't think that was mental illness, but extreme digestive upset.
When my cats make that noise, it's a prelude to a particularly nasty spasm of yacking. Usually, the yodeling lasts only a minute or two.
That poor kitty must have got hold of a Big Mac or something, but it could also having a bout of pancreatitis.
I doubt the bozos who made the video realize their pet may be quite ill.