I'm going to attempt a small 🧵 to explain ADHD in computer terms. Imagine your brain is a computer; you have working memory (RAM), long term memory (hard drive), processors (frontal cortex) and an operating system.

The operating system has a process manager which takes care of all the things. Some are daemons and run constantly on dedicated chips like breathing and sensory processing. Others need to be managed to interact with the CPU (the frontal cortex) to be active.

Most humans perform a type of preemptive multitasking where processes can interrupted and scheduled based on I/O waits, CPU needs, and timeslices. You can work on something until you have to go to the bathroom, or you need to eat, or just because it's time to stop.

In ADHD brains the interrupt mechanism is different. It wants to do something, anything really, and when it sees CPU and I/O dipping it assumes a new process needs to be spawned and given priority. It also will randomly terminate processes.

Most computers will defer to the user for what process has priority, the ADHD manager attempts to round robin task switch across all the processes without regard for what the user wants or needs.

Imaging you're using a email app and suddenly out of nowhere minesweeper opens and moves to the front. You didn't ask for it, but here it is, then as soon as you finish one level it opens a new browser tab and navigates to the wikipedia article about the Ottoman Empire.

There are also times when the interrupt mechanism will hand all priority to a single process and refuse to send scheduled processes to the CPU, need to eat? pee? sleep? No! Link can't save Zelda on his own, he needs me!

This style of processing isn't broken, it's just a different pattern. There are times when this task switching is beneficial as not all tasks really need to be given priority. Which is why ADHD folk tend to thrive in chaotic environments that stress out others.