I think it would be difficult for me to outwardly say "I'm mentally ill" because of the stigma attached to it. A lot of people think mentally ill means being unable to function and relate to others, when in reality that describes a small fraction of people who have mental illnesses. The term was used very negatively in the past, so I think it's just hard to say it without thinking of those negative connotations and allowing them to influence my feelings toward it. If I think about what the term 'mentally ill' actual means though - just a disease that affects the brain - I don't feel at all ashamed or disempowered using it and identifying with it. I also don't think of it as transitory because I think the actual root of the illness is always there (in my case a chemical imbalance along with trauma), but the symptoms (anxiety, depression, ED behaviors, OCD thoughts) aren't ALWAYS present. I don't know why this example came to mind, but I see it sort of like how someone with asthma only has symptoms some of the time, but that doesn't mean they stop having asthma just because they're ok at that moment.. they would still say 'yes I have asthma' if asked.