Lithium didn't dull me but it literally made my friend unable to hold a intellectual convo whatsoever. It was like talking to a child. She ended up getting toxicity and once she was off it, it was night and day. She was a whole different, better person. I also got toxicity from it. And alcohol may make you more dehydrated than usual with the lithium. Drink lots of water and remember those labs!! Some docs are lazy about ordering labs or don't remember so bring it up if you have to. Toxicity is serious stuff. My thyroid was messed up for awhile and my friend had to get dialysis from it!