Thanks for your responses. Gives me some peace!
I had the same question when I was newly diagnosed. What I have found is that there is evidence that bipolar can increase if left untreated. Google "kindling" to look at that affect. Supposedly, if you are treated for the disorder and take the proper meds, etc., it shouldn't get worse. Just think of having diabetes and not taking the insulin to stabilize your illness....same thing.
You will have to monitor the effectiveness of the meds, but with help from your pdoc and therapist, you will be able to do that. A strong support from family and friends is also very helpful.
Good luck! I take Lamictal and have had wonderful results with it.
Lamictal worked for a long time for me. Many people I know have taken Lamictal long term and things have worked out well. Lamictal is generally used long term and works that way. Sometimes its just a matter of getting medications fine tuned and then its okay after that.