I probably do not have ADHD but this is still something I'm struggling with. Except there are no consequences, which makes everything worse in that it only encourages me to continue like this.

Example:

2 months for writing a report for a course. I started reading and selecting the sources 5 days before the due date. I started writing 1 day (~36 hours) before the date and finished 10 minutes before it was due. (Note: I did take breaks for eating and sleeping). I didn't even proofread it beyond skimming for errors.

The result?

[–] astropenguin5@lemmy.world 4 points 2 days ago

Yeah that's fairly textbook procrastination and then deadline stress - driven productivity, which is fairly common for ADHD people. Not enough to prove it on its own, but if you also identify with a lot of other things in this community it may be worth looking into

A few other examples off the top of my head that I have:

executive dysfunction (trouble starting tasks, even that you 'want' to do
often abandoning hobbies and personal projects for new, interesting ones
trouble staying focused on tasks that dont have that immediate deadline pressure
trouble forming habits
often fidgeting/stemming when not thinking about it

And reminder that even if you don't have stereotypical 'hyperactivity' symptoms you still might have a form of ADHD, for example I don't, for me it just manifests as often fidgeting, but not much beyond that.