"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. Out of respect for Eva's privacy, we do not wish to discuss further details," her rep told PEOPLE Friday.
Cirque Lodge became a familiar name last year, when Lindsay Lohan checked in for treatment. The substance for which Mendes is being treated has not been reported.
The news was first reported on TMZ.com.
At last year's Cannes Film Festival, Mendes told reporters that to feel comfortable doing a sex scene with Joaquin Phoenix in We Own the Night, which also starred Mark Wahlberg and Robert Duvall, she required a drink.
The Miami-born Mendes, 33, is of Cuban-American background and first made a name for herself when she starred with Denzel Washington in 2001's Training Day. She played Will Smith's love interest in the 2005 comedy Hitch, as well as in the screen version of the Marvel Comic Ghost Rider, with Nicolas Cage.
Come fall 2008, Mendes will be seen in an all-star remake of the stage and screen comedy The Women, costarring Meg Ryan, Annette Bening, Debra Messing, Jada Pinkett-Smith and Bette Midler. For 2009, she has already finished the thriller The Spirit, directed by Sin City and 300 creator Frank Miller.
New Face of CK FragrancesThe same day news broke about her being in rehab, CNN Money also reported that Mendes, a previous spokesperson for Revlon, is the new face of Calvin Klein Fragrances, in an ad campaign that is slated to launch this fall.
Previous actresses and models who have been affiliated with Calvin Klein fragrances, the company said in a press release, include Kate Moss, Scarlett Johansson, Christy Turlington and Natalia Vodianova.