My gf has really severe ADHD (I have all the symptoms of depression but since I'm not allowed to go to a psychiatrist I'm not going to say I have it since I could be wrong) and she's struggling really hard in school but I still love her so friendly reminder: even if a friend/family member/significant other isn't "perfect" you should still support them. I honestly see too many people dumping their gf/bf/etc bc they have a disorder.
i think it depends on the person and the relationship - if someone has a partner who has a mental illness and it negatively impacts that person’s ability in a significant way to care for their own mental health, then the right thing to do would be to end the relationship.
though, there are some who don’t even try, or who get intimidated by a (potential) partner, family member, or friend with mental illness, and that’s often from a lack of understanding and maybe also some selfishness. it’s hard to say.
the point here is i think it’s difficult to judge a relationship that you’re not part of, and while the ideal would be for everyone to support and love their significant other, family member, or friend with mental illness, it can be more difficult than it seems.