Definitely a physical disorder. Neurocience can track it more and more clearly.

Me bipolar? One reason it took so long before seeking help, is that depressive episodes disappeared in a void in the past. Not a problem.
Hypomania was not a problem either.
Now my last depression has entered the void, and I am annoyed by the slight ataxia, side effect from Lamictal. I do not want to have it.

I was the one to discover my problems and identify it as bipilar2. The psychiatrist confirmed it and gave me meds. Sort of can't discard it all.