Yes, before I was diagnosed with Hypothyroidism. When the thyroid is off you can feel depressed, foggy, confused, lost, very blue, like there is a dark cloud hanging all around you, moody, tired and so on. Get it checked. Your thyroid reading should fall in the .5- 1.5 range. Though doctors say it can be a much larger range that is the optimal span. At my worst I was very depressed and felt like walking off and never returning wouldn't be an issue. Another time when the med was off I would have to strain to try and make sense out of simple sentences. My husband would say- Did you put the dog out. I'd stand there staring at him trying to think through how to even spell the word did.- It took quite a bit of convincing to get the doctors to see it as it was due to the switch in brand of med they gave me. You can also feel hyper even if briefly, irritable, sleepless and so on.