The actress, who is best known for her roles in 2 Fast 2 Furious and Hitch, checked into the Cirque Lodge clinic in Utah in January.
Her publicist said at the time that Mendes needed to "attend to some personal issues that, while not critical, she felt deserved some outside professional support".
The 34-year-old said she now intends to "take a break and have a good time" before signing up for any more movie roles.
She told People: "The sun's out again. It's my time. I'm actually taking advantage of my time off.
"You know, I had a film that was pushed, so I'm home spending time with my family, going to the gym and actually enjoying taking care of myself.... This year has been great for me because I've learned how to relax.
"The last three years have been amazing but kind of crazy. So I don't know, I feel grounded. I feel really good."