I developed this trick to deal with intrusive thoughts
(disclaimer, I don’t think I have ADHD or anything like that, pretty sure I’m neurotypical if one doesn’t count the depression, but if it can help me maybe it can help you.)
So my mind is always thinking about everything, and sometimes it’s a problem when I want to concentrate on say, a fanfic I’m reading, and a word reminds me of something which reminds me of something else, etc.
A couple of years ago I started envisioning this front space of my mind, the one I’m using, like a white board where things happen.
And when an undesirable thought came, I just wiped the white board.
I always visualise the same move, like a wipe to the left.
I’ve done this for a couple of years, now, and my brain is pretty well trained, so I just need to make the wiping gesture with my hand and the thoughts just leave.
(sometimes it’s thoughts of my loved ones, so I don’t wipe them, I just gently walk them to the door - always to the left- and bid them good bye. sometimes it’s horrible thoughts about horrible people, then the border or the white board becomes an incinerator.)
It works most of the time, and sometimes a thought needs to be wiped two or three times, but then I can reset the white board and imagine the fic I’m reading again.