So Chris Langham is a psychologist and Paul Whitehouse plays all the patients, some of them to perfection. There's only one series, and both the DVD release and series 2 were axed when Langham was arrested for downloading child porn. Luckily, we are the children of the information age, and the entire series is available on Youtube.
I can't help but feel sad that the second series will never be made and Langham will never work again - moral issues aside, he's a talented guy (who you may also know as Hugh the hapless minister from The Thick of It).
http://www.youtube.com/watch?v=8aVrKTnCsn8