The Psychiatric Hotline

"Hello, welcome to the Psychiatric Hotline."

If you are obsessive-compulsive, please press 1 repeatedly.
If you are co-dependent, please ask someone to press 2.
If you have multiple personalities, please press 3, 4, 5 and 6.
If you are paranoid-delusional, we know who you are and what you want. Just stay on the line so we can trace the call.
If you are schizophrenic, listen carefully and a little voice will tell you which number to press.
If you are depressive, it doesn't matter which number you press. No one will answer.

Where is the joke?