Courtesy of the brilliant mind of Chris I bring you The DSM-IV drinking game.

Step One: Acquire a copy of the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV).

Step Two: Open the book to a random page and read aloud the disorder name as well as its essential features.

Step Three: Everyone who believes that the disorder just read applies to at least one of their ex-girlfriends or ex-boyfriends must drink. Everyone who believes that the disorder applies to their most recent ex-girlfriend or ex-boyfriend must take an additional drink.

Step Four: Pass the DSM-IV to the next player and repeat until all players are suffering from either 291.1 or 291.8.