Was derren brown pre staged

No.

There are no actors or stooges used in his shows.

If you actually watch his shows, you can see how random the events are, so it is clear it is not staged. Sometimes things do go wrong, another proof that it is not staged.

Derren Brown uses psychology, hypnosis and persuasion to prove certain things, such as clairvoyance, tarot readings, miracle healers and so on, are fake.

So, Derren does REAL things to prove that other people are fake.