Can a thyroid imbalance cause depression or mood swings?

YES! Very much so. Get a thyroid supplement to help.

I thought that once, but had the doctor check my thyroid and it was normal. She told me it was hormones. She prescribed birth control bills even though I'd had a tubal after my third child.

Definitely. But other things can cause the same symptoms, too, so it's best to handle thyroid issues under the care of a doctor.

YES & YES!!! your thyroid controls most of your hormones!!! so if its out of wack it can affect pretty much everything from weight gain/loss to mood swings and so much more -- i had 2/3 of my thyroid removed because it affected me so drastically - in only a matter of couple months my mom said my personality did like a 180 and i felt like i was changing and was moody and i felt like i had no control over what was happening to me and finally my doctor noticed i had a thyroid issue and a fe months later after trying medication that didnt work for me, because i had a thyroid goiter, i ended up getting my thryroid removed and pretty much instantly i became my same old self again!!! it was great!!! i would definatly ask your doctor for a blood test of your thyroid (but keep inmind that if you have a small goiter your levels might be "Normal" as thats exactly what happened to me - my levels were "normal" but i still had all the sypmt

still had all the syptoms... and ended up have a goiter that went from nothing to the size of a baseball!!! - good luck and i would talk to your doctor

Yes! However, a full work up to rule out other causes for those symptoms is recommended. But yeah, when I don't take my synthroid for awhile, I notice all the symptoms of being hypothyroid... including being an emotional basket case.

Most definitely

Yes, if severe enough it can. I have hypo-thyroidism and mainly feel tired when my levels are low.

yes