No, 'retard' is really offensive in the U.S. as well, and is definitely not used by medical professionals (except perhaps in its verb form, ie 'to retard the growth').
This doesn't mean people don't say it, but it's definitely a slur with negative implications.
(frozen comment) Re: Um. Ableism?
(Anonymous) 2016-01-13 11:02 pm (UTC)(link)This doesn't mean people don't say it, but it's definitely a slur with negative implications.