Here are a selection of verbatim quotes, some of which were not widely reported at the time they were made. The frank nature of some of these confessions may surprise you.

Angelina Jolie: I hate heroin because it fascinates me. I am not immune to it, but I never want to try it again.

Colin Farrell: I ended up on a psychiatric couch and the doctor told me to write down how many times I did drugs in a week: 20 ecstasies, 4 grammes of cocaine, 6 grammes of speed, 30 grammes of hashish, 3 bottles of Jack Daniels, 12 bottles of red wine and 30 litres of beer.

Davina McCall: Name me a drug and I will tell you I tried it. Cocaine, ecstasy, heroin even – but I never injected it. I was working and it seemed like I had everything under control. But then sudden mood swings appeared.

George Clooney: When I was in college, I loved to trip. It was an escape. I also loved magic mushrooms. They were like a lighter version of a trip. I also loved cocaine. Cocaine prepared you for a party, but it never actually takes you there. Every time, you think it will be excellent, but then depression kicks in.

George Michael: Cannabis keeps me aware and happy – but it is obviously not quite healthy. You cannot afford to smoke cannabis if there is work to be done.

Naomi Campbell: It was one time at a concert somewhere in Europe when cocaine was offered to me. I felt invincible. As if I could conquer the world. I was simply self-confident more than it is normal. But this was all a misconception because when you wake up the next day and the effect of cocaine ends, you feel terrible. The more cocaine you take, the more you want it. And this is how you become an addict.

Sienna Miller: I still love unusual hallucinogenic drugs. If I could have my pick, it would be magic mushrooms.