Speaking at the Cannes Film Festival, where she is promoting her new film The Dead Don't Die, the 26-year-old said: "I think our world is going through a lot obviously.
"But for my generation specifically, social media has been terrible."
She claimed many young people were unaware of important news issues.
"It's a useful platform but it does scare me when you see young boys and girls not really aware of the news going on," she added.
"It's selfish - I don't wanna say selfish, that's rude - but it's dangerous for sure."
Gomez who has 150 million Instagram followers, was last year overtaken by footballer Cristiano Ronaldo as the most followed person on the platform, and she has previously taken lengthy breaks from social media.