Not wanting to sound anal about this, but...
Technically, Stan should never have even been allowed to join the Cult of $cientology. Sure, they would have gladly taken the $240 (actually, I thought it was a lot more than that, but what do I know, I'm no $cientogist) for his first audit, but in order to join the Cult, Stan would have had to have one of his parents sign a waiver, which never came up during this episode. Yes, boys and girls, $cientology just loves legal mumbo-jumbo. The waiver effectively binds you to the following:
1> That anything $cientology teaches you must be treated as the Gospel. Yes, you must respect them as a "religion." (Later on, as your life savings are drained and you're brainwashed a little more, they'll also legally bind you into the belief that L. Ron Hubbard is God.)
2> That you will forever NOT accept any advice from a psychiatrist or any other mental health professional. Remember folks, $cientology believes that psychatrists are evil, and psychologists are their bastard sons/daughters. And they must be destroyed. Maybe they'll find that "prison" where Xenu's being held, and disconnect that "eternal" battery. After a little brainwashing session, Xenu will then be ordered to round all those pesty psychatrists up and ship them to some volcanic island on some other planet, and drop them in along with a few H-bombs for good measure.
3> Of course, nothing that is taught by them can ever be revealed to anyone (unless he/she's another brainwashed member of the cult you've just committed yourself to.)
Failure to adhere to any of this will banish you - of course after signing yet another waiver that will get you sued if it's ever suspected you've ratted their "dogma" out to the outside world.
So
that's why Tom Cruise seems like a normal, stable human being.