In my jurisdiction, in the US, for an adult - it is, luckily, not quite that black and white or simple. There is more required before they are able to force someone to submit to the western medical profession than a mere verbal suggestion. People make statements all the time about harm to themselves and others that are off the cuff or the product of frustration/anger etc and not signs of mental illness.

I also consider it something someone might talk about as an interesting subject to explore in a theoretical manner.