I think an interesting part of your question is when you ask Or do you think the therapist will know and tell you? I have wondered this as well. Actually I wouldn't be surprised if my therapist were to tell me its time for me to stop, though she would probably say "take a break".

Having a chronic mental illness keeps me in therapy. Frankly I need and want the support I get from her. She is the objective voice that keeps me on track when things around me seem to be falling apart. I have gained many coping skills and could probably be fine without therapy. But, as long as I take something away at the end of each session, I will probably stay. I begin my 8th year with her in March.