In my professional experience, it can be hard to tell between ADHD symptoms and CPTSD symptoms. The checklist is not a great way to diagnose people. We usually do a lot more assessments, I also use a computerized test to measure reaction time and error commission.
I wish we (therapists) at least had the option to order an MRI or recommend a doctor orders one in difficult cases (I can do the latter but they will just laugh at me).