It's not necessarily ADHD. It's the underlying problem called Executive Dysfunction. Most people with PTSD have it to some degree. It can be full on ADHD. But usually it shows in some form of cognitive dysfunction. If you pour OJ in your coffee, put the Corn Flakes in the dishwasher, or if you have moments where you know something and can not remember it or you spend 10 minutes looking for the mobile phone that's in your hand.....you may have Executive Dysfunction.They were screening hard for ADHD.
Once I recognized what it was Cognition became a marker of how active my PTSD is. It's like math - Cognition>PTSD, and Cognition<PTSD.