Another way is through current trauma/pain. This is also immensely problematic; contrary to the theme of Rent, love cannot actually solve things like addiction.
Two romances--one television, one book--handle current trauma/pain in a realistic--and successful--way. In both cases, it involves a tough, no-nonsense lover who lays down the law.

Of course, there's no reason to rank them. Suffice it to say: while watching Bones, Season 10, I was chilled by Booth's downward spiral. I was worried that the writers would deliver some kind of panacea ("I love you, Booth"--"Okay, I'm cured!").
So, I was impressed when Bones, Brennan, lays down the law. She commends Booth for helping Arastoo in Iran. She gives him a chance to come clean.
And then she throws him out.
For someone like Booth, this is enough of a wake-up call. He goes to meetings, gets his life back in order, and gets back on the path to being a reliable husband and father.

This come to a head when Noah fails to meet Anthony when he comes to town because Noah is completely drunk. Again, Anthony doesn't fall for Noah's excuses. He doesn't apologize for his suspicions. He doesn't "forgive" Noah and accept his promises to start over.
He walks away.
What also impressed me is that Witt avoids the "so much pain=so much love" equation. Noah does stop drinking in part because of Anthony but also because of his friends and his job. That is, he realizes that he needs to put his life in order for himself, not simply to win back his lover.
Tough partners respect themselves too much to practice wishful thinking. And they respect their partners' need to respect themselves.