The 33-year-old star of "Hitch" and "We Own the Night," has been undergoing treatment at Utah's Cirque Lodge center for several weeks, the report said.
"Eva has been working hard for the past year and made a positive decision to take some much-needed time off to proactively attend to some personal issues that, while not critical, she felt deserved some outside professional support," a representative for Mendes told People. "Out of respect for Eva's privacy, we do not wish to discuss further details."
Cirque Lodge was in the headlines last year after actress Lindsay Lohan checked into the facility following dual arrests for drink-driving.

Copyright AFP (Agence France-Presse), 2008