For some reason the word “chronic” often has to be explained. It does not mean severe, though many chronic conditions can be exceptionally serious and indeed life-threatening. No, “chronic” means persistent over time, enduring, constant. Diabetes is a chronic condition, but measles is not. With measles, you contract it and then it is gone. It can sometimes be fatal, but is never chronic. Manic depression, in other words, is something you have to learn to live with. There are therapies which may help some people to function and function for the most part happily and well. Sometimes a talking therapy, sometimes pharmaceutical intervention helps.

Stephen Fry