Difficulty regulating emotions is a component of ADHD. ADHD is a shortcoming of executive function, which manages near-term memory and keeps people "on task".

Difficulty regulating emotions is a component of ADHD. ADHD is a shortcoming of executive function, which manages near-term memory and keeps people "on task". "I'm going to endure this unpleasantness for a better future" is a goal that requires executive function to hang on to – you have to continue grasping it with the part of your subconscious that ADHD undermines. So you end up prone to a brand of nearsighted emotional hedonism because it's difficult to keep track of the "why"s that motivate long term management of emotions. It's basically time blindness. In other words, keeping your cool, keeping your word, and keeping your car keys are all "keep doing X", and ADHD will kneecap all of those in equal measure. A second component – and this is just anecdotal – is that ADHD makes the emotional component of procrastination worse. You drop tasks more often, and if you've got any self awareness at all, you'll notice that. Of course you feel a little bad about it. Now noticing dropped tasks makes you feel a bit worse. But your ADHD means dropping more threads, so you feel more badly more often. The pit of emotional misregulation surrounding procrastination gets steeper, faster, for someone with ADHD, because there's a compounding fit where you're twice as likely to take blows to your productivity, and half as able to recover.