I don't think emotional and mental illness are disabilities because they can be cured and I said it was only one of the characteristics. Well, they are illness. If you are blind, you will be PERMANENTLY blind, 99.9% of chance you will have it for the rest of your life. You cannot change it and unlike stuttering, you can not be coincidentally not blind for a second, just because you are having a "good" day. From this particular aspect, I'm still gonna say stuttering is not a disability due to its high volatility.