Motdakasha, the DSM is also a social construct
. Behavior that may be called mental illness in one society may not be in another. There's a much better definition (IMO) of mental illness than "something that's in the DSM." I think its safe to say that if someone has unusual thoughts or behavior that interferes with their daily life, then there's a "problem." There are certainly people who require sex so much that it ends up hurting them. By "require," I mean that the person would become depressed or otherwise dysfunctional if going without sex for a short period of time.
And your quote mentions Bill Clinton as a proposed "victim" of this - that's amusing. Having affairs doesn't mean that you're addicted to sex. There are many other more likely explanations.