If you had/have a partner or SO, that suffered from mental illness?

If you are currently involved with a person who is suffering mental illness, or have been in the past I would appreciate your experience with the following:

Did you take time to find out about their illness? Did you then take steps to assist them in their recovery? In which ways? How did you for example handle volatile situations? Did you respond angrily or were you patient? Or did you decide to leave them with no further thought on the matter. If this is the case did you in fact love them?

I ask this question for another person, not myself. Who is battling bipolar and their SO could maybe do with some advice. (In a place where there is little advice I think). I am leaning toward asking her to go for counseling to assist her in her own struggles with it currently. I understand the ‘patient’ needs to sort themselves out, but there is a tendency for one to think that once the person does that; all is well. Whereas I personally feel both partners need help and assistance. Any feedback appreciated.