Can be used as a noun, adjective, verb, much like it's vulgar equivalent - Fuck.
Effed can be used to describe a state of complete and uttter mental anniahlation after consuming more the recommended dose of narcotics, legal or otherwise. As a result. this may lead to a domino effect of effed situations.
Man that pill was effed! Like seiously are you as effed as I am right now. That's effed up! Hey anyone seen Aaron? He left the apartment all effed but left his keys and phone behind. He's Effed...he'll be fine.