On Writing: Mental-Illnesses

Where Wattpad Tends To Fuck Up.

"For a person to be considered mentally ill, they must have mental problems so severe that they disrupt a person's life to the point that the person's physical wellbeing or the wellbeing of others is at risk if the person is left untreated."
Boom.
Someone who is mentally ill can't function in everyday life like a neurotypical (someone without a mental illness) can. How we can't function differs depending on the mental illness and the person themselves. Actual violent impulses/urges aren't always involved, although for some of us it is a very real and very traumatizing struggle not to genuinely lash out and beat up anyone who gets too close. It isn't fun. And it especially isn't selective.
Now, let's get down to the fucking nitty-gritty of why Wattpad writers fuck up a lot.
Your character can believe they're the reincarnation of Cleopatra. Your character can have a voice in your head claiming to be Elvis Presley. They can mutter under their breath, rock themselves/twiddle their hands to calm themselves down, you can have them paint every room in their house pink as the sunset and the windows all emerald fucking city green, but as long as that character can function in society and around other people without posing an actual serious risk to anyone, they don't qualify as mentally ill.

Giving your characters these little cute and funny quirks to make them mentally ill or insane is harmful, toxic, and it's gross. It's vomit-worthy. It frankly makes you a bit of an ignorant, derogatory asshole.