The psychiatrist swears that the Lithium can't be causing such increased weight gain. Online search and folks here say different. I was just catching up on some threads from the last few days and janet discussed Cory and the lithium causing the thyroid issues. I know Q got his checked at the time of starting the Lithium. But nowit has been since mid Oct..... the weight gain, the tiredness that happens during school and he shuts down, he is walking around our house with a coat on and a hat too, begged me to turn on the fire but out house if a good temp. He has been saying those things about wanting to die and knowing how to end all of this etc.... he never had ongoing depression before. If not a direct side effect of the lithium, I wonder if we need to check his thyroid to see how it is being affected. He goes to all three docs jan 2 and jan 3 so I will ask pediatrician to check it because they do blood tests right there in the room with people who know him and have worked with him nicely for many years (since age 2). I will ask the other docs if they need anything checked so we can do it all at once. I know they want a vitamin D level again too so we can do it all at once. What other symptoms should I watch for?