I'm going to say I wouldn't date any depressed person in front of a group of depressed people
Why do you want to date people then?
I'm dating people because I like spending time with them, not because I want to be friends or because I like their body.
It is good to be open to others about your dating preferences. If you are not willing to care for someone who has mental issues, then you should not feel forced to do so.
So why can't I say that I wouldn't date a depressed person?
You should be more polite and tactful when making your preferences known.  You really have nothing to gain by essentially criticizing a group of people like this, but it hurts them to be reminded of the way that others consider them a burden.