Post Natal Depression 

The feeling you get after shelling out for the Xbox 360 peripheral "Project Natal" and realising it sucks.

A: Whassup dude, yo is lookin down.
B: Yeh, I iz broke coz all my monies went on Project Natal and It done be no good.
A: Ah no blood, yousa got Post Natal Depression.

Post Natal Depression by G0N. June 19, 2010

Post-nutal depression 

The existential crisis that occurs after nutting

Friend 1: I just jerked off and now I’m sad
Friend 2: bro I think you’re suffering from post-nutal depression

Post-nutal depression by ThePropertyBrothers November 3, 2019

Postmatal Depression 

A brief period of sadness that occurs after a friend you've been spending a lot of time with leaves.

Alex: Hey, how are you?
Nathan: Feeling a bit down.
Alex: How come?
Nathan: No, nothing. Just had some postmatal depression since John left this afternoon.

Postmatal Depression by JimDan November 21, 2010