Adele

The 'Rolling in the Deep' singer confessed that she felt "inadequate" after giving birth to her son Angelo.

In a tell-all interview with Vanity Fair magazine, she said: "I can slip in and out of [depression] quite easily. I had really bad postpartum depression after I had my son, and it frightened me.

"I didn't talk to anyone about it. I was very reluctant...Four of my friends felt the same way I did, and everyone was too embarrassed to talk about it."