
I pondered it for all of ten seconds when I realised that since
we don't have any reliable statistics for sexual promiscuity,
and since the whole issue of "depression" isn't at all well 
defined for earlier centuries, you are probably talking crap.

Of course, you could pull a Mozumder on us, and say that people
who are having sex outside marriage are *defined* to be depressed.

I can't say I'd ever noticed, myself.