The actress entered the Cirque Lodge facility last month amid reports she was battling substance abuse issues.
Her spokesperson revealed she was making a positive decision "to take some much-needed time off to proactively attend to some personal issues"--but Mendes left the center on Wednesday and was spotted getting on a flight to Los Angeles.
The sighting prompted Life & Style magazine to inaccurately claim the Hitch star had left rehab to return to her California home.
But her publicist insists the actress is only taking a short break from treatment at Cirque, and will be checking back in soon.
The representative tells PageSix.com, "Eva is attending to some personal business in Los Angeles and intends to return to complete her treatment shortly."
The Cirque Lodge has become a leading celebrity refuge in recent months--Lindsay Lohan spent last summer there; rocker Richie Sambora also stayed at the facility last year, and actress Kirsten Dunst has reportedly just checked in.
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