Susan HeitlerWhen you’re in a great friendship, it boosts your immune system. But toxic friendships are sickening. While relationships often have ups and downs, if you're on a wild ride, you may want to think about hopping off before you turn green. Friends are supposed to add to your life, not take away from it. Thank you to one of my best friends—Sharon Livingston, Ph.D.

~ Susan Heitler, Ph.D.