When I had my head injury 14 years ago the wife contacted DVLA, they we only concerned if it was a severe brain injury, we were a little surprised.
My neurosurgeon confirmed in writing after some test that I was no more risk than the average driver. I have undergone test for epilepsy were they try to induce a fit plus spacial awareness test all which I passed with flying colours.
The problem lies with other peoples uneducated assumptions, just because you have a mental disability does not make you a bad driver, and too be honest you will probably better than some of the abled bodied people who’s over confidence is not matched by their talent.
Unfortunately I have suffered a brain injury and occasionally I get confused and often say the wrong thing.