I started having this problem around 40. A lot of it came from a heavy marijuana habit that seemed to reduce my working memory with the tradeoff that I became more clever at small-scale problems(I call it a tactical vs strategic tradeoff).
Quit smoking pot and things got a lot better for a while, but then things seemed to resume their downward slide. Sleep apnea didn't help, and treating it made things better for a while, but that slide continued.
Now I just try to manage it with lots of notes, scripting everything I can, and trying to simplify my workflow wherever possible. Hopefully things stabilize in my 50s or I don't think I'll be good for much engineering work beyond that. I have a number of dopamine-related movement disorders though so there may be some special issues in my case.
Yeah the problem is "dopamine" means many things in the brain. You can have too much one place and too little in another. Or you could have too much along with a declining population of dopamine neurons in certain areas. I'm type II bipolar which is theorized to be an issue with dopamine regulation and also suffer from essential tremor and spasmodic torticollis. So in my case I probably have issues in several areas.
Quit smoking pot and things got a lot better for a while, but then things seemed to resume their downward slide. Sleep apnea didn't help, and treating it made things better for a while, but that slide continued.
Now I just try to manage it with lots of notes, scripting everything I can, and trying to simplify my workflow wherever possible. Hopefully things stabilize in my 50s or I don't think I'll be good for much engineering work beyond that. I have a number of dopamine-related movement disorders though so there may be some special issues in my case.