Wow, I did not know this!!
"PMDD disproportionately affects people with ADHD and autism, with up to 92% of autistic women and 46% of women with ADHD experiencing PMDD, though estimates vary6 7. There is no agreed-upon cause of PMDD, nor is it known why it affects certain populations more than others, though there are various theories."
www.additudemag.com/pmdd-autism-adhd/
I've always suffered. I have dreadful periods and my mood changes up to ten days before hand. The 5 days before it, I'm awful though.