Does Contrary change the effects of items and Natures?

Question

I was just wondering if a Pokemon's Nature was inverted if they had the Ability Contrary. For example: would a Jolly Pokemon have a buffed Special Attack and a nerfed Speed stat instead?
Also, if a Contrary Pokemon was holding an Iron Ball would its Speed be buffed or nerfed?

Thank you.

Answer 1

Only stat changes are affected by contrary. So natures and items act as they would on any other Pokemon.

Source: Personal experience and various sites.