Shouldn't the proof need to go the other way? You're postulating that a magic compartmentalization factor exists in Sisko, and in fact is the default for most people suffering from clinical depression, without providing a basis for said factor.However--even without that, if his depression is such that it would lead him to make irrational decisions in his personal life, surely it is not that big of a stretch to be concerned that it would affect his professional life?
Prove it.
(I can only approach clinical depression from my admittedly semi-informed perspective of someone who's suffered it but hasn't done much independent research into it. But from what I know and what I experienced, I find myself agreeing with Rush Limborg here, and find the idea that clinical depression would affect Sisko's personal life but not his professional one... unlikely. Especially when it did affect his professional life during the "Emissary" timeframe.)