Lexapro (escitalopram) at 10 mg seems to help ocd very much where as luvox at 300 did not...yet lexapro (escitalopram) is not indicated for ocd as luvox...can someone explain.. ?

Probably not: From what I've seen - the variable effectiveness of all the psych medications in different folk for different conditions is unexplicable. Just be glad you found something that helps very much. Not everyone does. Also the doses are not comparable. It's a bit like foreign currencies when a dollar was equal to a thousand lira. Don't expect it to make sense. That's hard for an OCD, but it's true.

Lexapro: Lack of the FDA indication means it was not tested rigorously for that particular diagnosis. But many medications are used off label.