How do I say "crazy" or "insane" in Japanese?

Question:

I've read that its kichigai, but I also read that that's a swear word. Is that true? I was going to use it in a username, but I don't want to offend anyone.

Answer:

There's too many ways, so I'll just write each one I can think of:

kuru kuru pa

kurutteru

ki chigai

kawatteru

hijoushiki

ki chigai is probably the one you are looking for. It is hard to explain just what 'ki' means. It is something like emotive force... like your heart or mind. And, chigai means 'wrong' so it is like saying a person is 'off.'
kuruu (long u on end) means to loose one's mind. Where "mind' means one's correct state of mind; hence, to go insane. You probably won't hear that as often as ki chigai.
Finally, baka is often translated as 'crazy.' What baka means is someone who is mixed up and/or a fool. Baka ni suru... to make a fool of (someone) ...to confuse someone (purposely)

Hope this helped :)
<3