Which qualifies something as an addiction?

Addiction definition: There are various ways of defining addiction, but basically it consists of continuing to use a substance or engage in a behavior despite negative consequences. Usually there is tolerance that develops, (it takes more & more to get the desired effect). Sometimes there are withdrawal symptoms when you stop, but not always. Many relapse after abstaining for a while, especially without a support group.

I agree and: Action or substance initially pleasurable but may no longer be--life faltering & sliding down into joylessness, isolation. Scary lack of control in stopping, maybe blithely unaware how destructive addictive behavior or substance is. This chronic, treatable brain disorder often requires intervention or recognition life is so bad, help must be sought (a bottom is reached). Watch for cross addictions.