Mad Love (movie, 1995)

Matt falls for Casey, the new girl in school. She's fun-loving and eccentric, but there's a darkness to her whimsy that Matt can't begin to comprehend. When Casey attempts to commit suicide, her parents place her in a mental institution. Matt springs her out, and together the young lovers head on a road trip. They believe their love can "cure" Casey's problems. Matt starts to wonder, though, if are they inspired or misguided.