No, I have bipolar disorder, but I don't usually announce that to the world because my medical condition isn't particularly anyone's business any more than their's is to me.

If I do discuss it with people who I feel need to know that information, I call it what it is. People with difficult physical illnesses don't say "I'm physically ill." They put an actual name on what the condition is generally: cancer, lupus, diabetes, Parkinson's, etc. People then have a fair idea of what they are talking about. But to just say "I'm mentally ill is not really informative, educational, or even descriptive. It pulls up that stigma that people have against what they don't understand.

I have found people much more receptive to a specific name for my condition than to some nebulous "mental illness". In fact, I find they actually ask very intelligent, supportive questions and really want to be better informed if just given the opportunity to have a name for what they are trying to understand. Mysterious "mental illness" carries its stigma very much due to it being kept general instead of it becoming personal and specific to people who really know those who deal with this.