Personal Health
Repeated failed attempts to cut down or control the behavior, and needing increasing amounts to achieve the same effect (tolerance).
Repeated failed attempts to cut down or control the behavior, and continued use despite clear health, relationship, or work problems.
Brief withdrawal-like symptoms when stopping, and occasional missed deadlines with immediate remorse.
Growing preoccupation with the activity (thinking about it a lot), and gradually withdrawing from previously enjoyed social activities.