I take lithium too! I also have hypothyroidism, the treatment is one pill in the morning. One thing I found out the hard way is that some high blood pressure meds will result in toxicity. I used to be really worried about toxicity but having gone through a minor episode with no long term effects, I am much more relaxed about it. I still get 3 monthly blood tests and check any new meds with my pharmacist. It has been a great medicine for keeping me stable for over 5 years. (I do take antidepressants or antipsychotics with it for emergent episodes)