Effective Date of Claim

I wanted to know has there ever been an issue when trying to argue your effective date after being awarded years later for the service connected disability? My first rating was in 2011 for PTSD but was denied and i didn’t file anything every year up until 2019 and it’s been continuous. Couldn’t one argue that due to PTSD that one didn’t have to mental capacity to file every year? Thus back saying my effective date? If so, what would be the most effective option?