From what I've read, depression after quitting smoking weed is a very very common thing. In some people, it can be serious.

The Erowid site has really good info on various cannabis effects, including those after quitting. They refer to "anhedonia," which is reduced experience of pleasure. Depression and anhedonia feel a lot alike.
http://www.erowid.org/plants/cannabi..._effects.shtml
birdgirl73 Reviewed by birdgirl73 on . would a smoker get depressed if.. they hadnt had a smoke all day (and no weed for a couple days?) any information would be nice, thanks Rating: 5