OK, you're probably saying to yourself "this guy is fvckin' crazy, how could he say such a thing?", but hear me out. Maybe I can get you thinking.
Mental illnesses are illnesses of the mind, correct? They are not illnesses of the brain, because then that would be classified as a physiological illness. But where is the mind? Can we see, feel, touch, or even measure the mind? So therefore, how can something (the mind) that cannot be measured, have an illness?
Anxiety, depression, eating and personality disorders, phobias, etc...it's all bullsh*t. There have even been numerous studies done where people with "mental illnesses" were given placebo medications (sugar pills) thinking they were real drugs, and their problems were solved! They rid themselves of their "mental illness". Why? Because they never had a mental illness in the first place!
You can disagree with me all you like. But I just want you to think about it for a moment. If you cannot measure something, how can you say it has an illness?