I'm going to tell my girlfriend that her actions recently are the result of a mental illness
Do you think it's your place to tell your girlfriend this?
I see that her actions are the result of the mental illness she suffers from, not because she has empathy for me or other people.
It is not up to you to determine what behavior is the result of a mental illness. You do not have the education or knowledge to make such a statement regarding anyone. Keep your opinions to yourself.
I'm going to do it anyway. I think that all people should analyze if mental illness is the cause for people's actions.
I see how you are just trying to care about her, but sometimes words need to have a little more tact to it so they don't offend. I think it's best to just leave it to the professionals and not be an armchair doctor. They would be able to assess her properly and get her the right treatments.