It depends on the chemicals added to your brain. Real brain damage is usually something that has physically altered it in such a way that it cannot repair itself. The brain repairing itself--"neuroplasticity"--is relatively new research.
It's kind of like hardware in a computer. Stomp on the processor and you're out of luck. But we are still learning what in the brain is hardware and what is software, 'cause those are metaphors and the brain works with chemicals and tissues which sometimes act like hardware and sometimes act like software.
Talk to/work with professionals (i.e., psychiatrist, pscyhologist, medical doctor, actual researchers) who you trust will give you unbiased answers--someone who you know hears actual symptoms rather than merely going through a check-list.
Understanding ourselves requires working through mazes of knowledge, some if it accepted, some of it disputed.
We are living in a time of revolution in understanding the brain. Which means: this is the worst time in history to ignore something you know from *your* experience of *your* brain. You may have to repeat that experience to pros a lot; you may have to go out and find research to bring to them that shows them your experience is similar to others. You may have to find other professionals to work with.
It can take work, even with a professional, to find the right answer. I'm not one of them, I just have experience working with them--and I love reading about neruoscience.
-jmv