VDTs are mentioned a couple of times in The Matrix Revolutions, both times in connection with self-harming, both times in connection with Bane:
Maggie: The Captain has some questions for him. He better have some good answers. You see these cuts? I think they're self-inflicted.
Trinity : Why?
Maggie: VDTs, maybe. I don't know. But like I said, the answer had better be good.
So, what are VDTs?
Oh, and for the record, if you're planning to tell me they're (Virtual) Delirium Tremens, you need to back it up with actual proof, not web-speculation :-)