I literally just found your post on google while looking for the exact same thing. I’m 26 and I was diagnosed with ADHD two years ago. Around the same time I swapped from the copper IUD to the hormonal IUD (releases progestin hormone levonorgestrel into the uterus). The copper IUD was amazing except for very heavy periods and intense cramps. When I swapped, I went from being in a really good place mentally to months of horrendous mood swings to the point of being almost suicidal. I don’t really get periods anymore and my mood has definitely stabilised somewhat, but along with other medication side effects (ritalin) it’s really hard to know what’s really me.
Despite being diagnosed less recently than you, it’s only in the past few months that I’ve actually really started looking at how seriously ADHD affects my life (is that a symptom?). I never even considered what the differences in hormone levels could have in regards to birth control. There are little to no people that I know with the mirena who have had any problems with their mood at all, except when I started googling and came to an ADHD subreddit..
As a teenager I took the combined pill and then the injection (which I’m pretty sure was worse). I was also super depressed, and I didn’t know I had ADHD. I have no idea what was correlative or causative, but I’m pretty sure that I felt overall less bad during the years following, when I was on a hormone free birth control.
I also can’t find a single journal article with anything more useful than ‘a study needs to be done in this area’, and it’s really annoying, because as you said, hormones have such a huge part to play.
Hit me up if you find anything else, or can convince someone to actually do a study..