Committing to a long-term relationship is a big deal--especially if you have doubts. With a focus on common sense over emotion, world-renowned sex and relationship therapist Dr. Ruth Westheimer offers straight-up advice on whether you should stick it out or cut your losses and move on.

In Stay or Go, Dr. Ruth divides troubled couplings into three "flavors" Dark Toxic (run ), Rocky Road (rough patch ahead), and Merely Troubled (it's worth the effort). She knows relationships are rarely black and white--there's always the bad with the good--so here she helps you determine where...