Personally, I don't think there's much of a difference. Both need constant care and attention. Both are in pain - mentally and physically - only difference is, in cancer patients the physical causes the mental and in mentally ill patients the mental causes the physical. My fiance's mom has been doing pretty bad lately. She has stage 4 cervical cancer and the past few days, she's been really upset, anxious, can't talk, eat, or move much. And I've noticed how my fiance became a lot more caring and aware that this is bad when she took a turn for the worse. He's very attentive and compassionate now because he realizes she's going to die soon. I am suicidal, with mood and personality disorders. I often suffer from depression, anger, and anxiety. And my life is in danger some days as well. With cancer patients, it progressively gets worse (if not treated or too advanced), and with mentally ill patients the same could be true or it could be a rollercoaster, where the person is awful some days and not so bad others. But either way, their life is in danger too. I can't eat, sleep, get up to take a shower, or go to school some days either. And I just feel like he doesn't see the similarities in myself and his mom. He could be just as attentive and compassionate to me too and it would help a lot, but he's not always like that. So I told him that in a lot of ways, I'm just like someone with cancer and need the same things...except that I am still able to function sometimes, but not always...and rarely ever very well. I hope it helps him understand. A lot of his actions have to do with the stigma that physical pain is more real than mental and it's really not.