As I understand it, these various disorders are rather fluid.
There can be depressive and manic states. Various medications need to be managed and often need to be changed.
I have witnessed extreme depression and zerO is not it. I have witnessed extreme mania and I don't see that, either. But, if he's correctly medicated, he could display the flat affect that is variously termed *cold*, *aloof* or *cerebral*. That does describe zerO.
I think he would need to be observed off his meds or in a period of stress where the meds need adjustment to make any accurate observation.
And you are correct: depression or even bi-polar is not longer a stigma. But they do affect judgment. I really would hate to find out that this is the case. Extreme stress could undermine any positive effect from medication and that would be when it would be observable, if he really has this spectrum of disorders.
What am eye opener of a quote. I find "this possiblity" not troubling, but frightening!