Why would someone get depressed after a session? Is it becuase they're mean to you? Is it becuase it's so exillerating and hot that normal life is dull by comparison? Is it becuase you like the people and miss them?
questions seconded...
It's not any of those things, says my research.
Like any other depression, it is caused by the chemicals in your body. Perhaps the session was a little too intense and caused an overpowering rush of hormones, perhaps the Dom neglected the aftercare a little...
Have you heard of people what have started crying and felt terrible during a massage? Same thing here. You push the body a little extra, get a rush of hormones and bad things go to the surface.
One way to help a subdrop is for the Dom to make sure the aftercare is -good- and -long- and that the sub feels loved, comforted and safe after a session. One might want to take a break from sessions as well, to let the sub recover.
I'm not supposed to know thi stuff. D': What's wrong with me?
EDIT: There is also a thing opposite of Subdrop called "subspace."