I agree a person with bipolar can still have natural mood shifts, but what you are describing doesn't seem natural, it seems to be a function of the bp. Perhaps just contact her and let her know what's been going on. I would also ask her what her reasoning is on the 100 mg dose. I know you're in South Africa, but I think it's still the same med, and just marketed under the name lamictin (I think??). What I have read is the average therapeutic dose is 200 mg. Certainly everyone is different, but I would still ask about the dosage because something isn't working.