I did not start having my emotional lability issue until after giving birth. I have suspected the hormones did trigger it for me, and I have asked doctors. They have checked my hormone levels, thyroid, all possibilities for things being ‘off’, but those numbers are always fine.
I did try many meds over all these years, they did not help the emotional issues, in some cases I feel they exacerbated it. I do not feel like any med caused a new issue that I didn’t have, though.