450 mg of lithium is pretty low. The only way to know is to have your blood levels checked. I didn't get to a therapeutic level until I took 900 mg. It was very calming for me. I was at 900 as a stop gap while I ramped up on lamictal. Now that I've started decreasing the lithium, I notice more anxiety and unease. So, for me, it seems to work. I just want to get on something that's less toxic and doesn't require drinking so much water that I walk around sloshing. Bottom line: it's a useful drug. Just make sure it's being monitored with regular blood tests. And drink a lot of water (I drink close to a gallon a day).