The `Poker Face` singer began using illegal substances after she dropped out of a music course at New York University in 2005, and she insists getting high helped her creativity.
The 24-year-old pop star said: "[Using drugs] I really figured out the art I wanted to make and was inspired. Some people find inspiration in dark places. I guess I`m one of them.
"What always made me different is that if I was doing drugs I was also making music. I wasn`t just doing drugs."
The eccentric singer - real name Stefani Germanotta - also revealed her mother Cynthia didn`t understand why she felt she needed to take drugs and was confused by her early performances.
She told Q magazine: "At the beginning I was doing performance art in handmade leather and leopard bikinis talking about oral sex and Andy Warhol and heavy metal. My mom was like, `You`ve lost your mind.` I was doing drugs, I was really out of control. But I never got so far into it that I overdosed or anything."
However, Gaga is adamant she doesn`t need drugs anymore and has toned down her wild lifestyle.
She explained: "Once you open those doors they`re open for ever. People who say they need [drugs] to be creative are full of s**t. I`m not some chick on the road getting high and f***ed up every night. I wake up, drink coffee and get on the phone to talk about the creative direction of the next video."
The singer caused a furore recently when she admitted in a magazine interview she occasionally took cocaine.
She said: "I won`t lie; it`s occasional. And when I say occasional, I mean maybe a couple of times a year."