"Is everything ok there?"
"Trying to cope. I have my down days and etc."
*silence*
-
"How are you doing?"
"Not good but nobody wants to hear that. Have a good day ahead :)"
*silence*
Nobody wants to know if you're not okay. They've got their own problems to deal with. You should be expected to deal with your own demons, too.
Best format of reply, for future reference:
"How are you?"
"I'm great :)"