The Department of Angst deals with excessively angsty fanfiction of any genre. They will tackle minor Sues and moderate bad slash or crossovers, providing the overriding fault in the story is canon-bending angst. New members are given a list of contacts in other departments whom they may ask for advice and help with assassinations, exorcisms, etc.
The methods of the DOA involve balloon animals, sock puppets, glitter rain, sunshine (produced by special lamps), origami, chocolate, and medication. Anything, basically, to dispel enough uncanonical angst for the canon to reassert itself. As always, canonical tools are preferred over non-canonical ones, and DOA agents are instructed to cheer characters up without recourse to drugs if possible. Especially severe cases may be sent to the Department of Fictional Psychology, but if the DOA agents can handle it themselves, they should.
In addition to the usual PPC gear and a host of mundane cheer-inducers, the DOA have access to some mood-altering drugs. These include "PPC-modified Benzodiazepine – Addictive Properties Completely Removed!" and "Perphenazine – Completely Elf-Safe!" They may be given via a spray hypodermic a la Red Dwarf or Star Trek. They come with a book entitled Psychotherapeutic Drugs for Dummies – A Reference for the Rest of Us.
It should be noted that supernatural beings, such as angels in the Good Omens-verse, may have more sensitive metabolisms than humans. As Agent Trojanhorse advised newbies Lasa and Mombi after they set Aziraphale literally bouncing off the walls with a standard shot of benzo, "less drugs, more hugs."
Missions from this department are listed on The Complete List of PPC Fiction, Department of Angst.