Kate Moss’ younger sister has revealed that she is in rehab for substance abuse. Posting to TikTok, 24 year old model Lottie Moss shared a video where she revealed that she’d checked into rehab as she continues to battle her addiction to the Class A drug cocaine. During the clip shared with her 25.8k followers, she said “When people ask why I'm in rehab." She then lip-synced the sentence: "I have a really bad addiction to coke." But as Lottie candidly discusses her time in rehab, what exactly is it and what rules are there? What is rehab? Rehab clinics are places that help patients overcome their addictions thanks to the help of physicians, nurses, counsellors and support workers.