Clara McGregor has revealed she battled a tranquiliser addiction

She said: "When I was on Xanax I had no energy, and I would start forgetting things. That's the scary thing, I would forget whole chunks of days. It was incredibly hard for me to get off them, but I didn't want to be in that space anymore and would never consider taking one again.

"Anxiety is suffocating. I'm 25 now and I've spent a lot of time working on it with therapy but it's only in the last three to four years that I feel less constricted by it. My sister Esther and my mum are a great help."

Clara was initially prescribed the drug - which activates a brain chemical known as gamma-aminobutyric acid and therefore slows down activity in the brain - as a result of suffering from poor mental health.

The brunette beauty - who has recently been appointed global ambassador for Bluebella lingerie - admitted that due to the crippling anxiety she says she suffered from the age of four, she would "never" have been able to take part during those difficult years.

She said: "I simply couldn't have done this campaign before. To jump on a plane and meet new people and shoot a lingerie campaign. Anxiety is suffocating and you just end up limiting yourself, it makes your life a lot smaller. I'm 25 now and I've spent a lot of time working on it with therapy, but it's only in the last three to four years that I feel less constricted by it."

Clara also went on to admit that her mother Eve and her sister Esther, 19, play a huge part in her mental health these days.

She said: "My sister Esther and my mum are a great help. If I'm going through it, it often helps just to talk through it with them."

It comes as the model is set to start work on a movie starring alongside her dad which sees Ewan play a struggling father who takes his drug-addicted daughter to rehab.

Clara said: "My father is playing my father in the film, and it's a road trip film and it's something that was very loosely inspired off of our relationship."