Brand, 37, discusses his battle with drugs and alcohol in "Russell Brand: From Addiction to Recovery," a program to air this month on the BBC.
The Sun newspaper said it features footage of Brand sitting on the floor of a bleak flat, smoking heroin when he was in his 20s.
The "Arthur" and "Forgetting Sarah Marshall" star is seen in the documentary watching the clip in a suite at London's Savoy Hotel, the newspaper said.
"A proper little junkie," The Sun said he told his friend, producer Martino Sclavi, in the program. "This is when you know it's a disease. It doesn't matter that I was sat in that flat in Hackney and now I'm in the Savoy. I'm jealous of me then.
"It doesn't make a difference to me. The money, the fame, the power, the sex, the women -- none of it. I'd rather be a drug addict."
Brand went on to clarify he knows how much his addiction damaged his life and how much better off he is since kicking the habit 10 years ago.
"The consequences of my actions affected so many people," Brand said. "Heroin is a greedy drug; it'll take everything. First, it'll take your money. Then, it'll take your friends, your family, your car, your house. Then, it's going to take bits of your body. In the end, I used to be scoring with people that had eyes missing, limbs missing. You'll take it until it takes your life. It'll take everything until the last thing and you'll gladly give it that rather than give up the drugs."