Kris Jenner thinks Rob Kardashian is "emotionally unstable"

A source shared: "Kris doesn't want Rob on the show when he is emotionally unstable."

Up until recently, Rob has been hiding away from the spotlight but a post on his Instagram account - where he compared his sister Kim Kardashian West to 'Gone Girl's psychotic Amy Dunne - ensured he was back in the headlines, with those close to him worried about his "unhealthy mental state".

They said: "The attitude has always been that when Rob gets his act together, starts working out and loses weight, everything will be good and he will be happy.

"But behind the weight gain is this very unhealthy mental state that he keeps struggling with."

Another insider has claimed the sock designer has "retreated" more after becoming increasingly "depressed".

They added to PEOPLE magazine: "He has retreated more. He's sad, he's bitter, he's single. He is very depressed and has been [for a while]."