Amanda Seyfried has opened up about living with obsessive-compulsive disorder (OCD) and said that she would never get off her medication. The Mamma Mia! actress revealed that she has been taking antidepressant since past 11 years for the condition.

In an interview with Allure, the 30-year-old said that like other diseases "It [mental illness] should be taken as seriously as anything else".

"I'm on Lexapro, and I'll never get off of it. I've been on it since I was 19, so 11 years. I'm on the lowest dose. I don't see the point of getting off of it. Whether it's placebo or not, I don't want to risk it," Seyfried told the magazine.

"And what are you fighting against? Just the stigma of using a tool? A mental illness is a thing that people cast in a different category [from other illnesses], but I don't think it is. It should be taken as seriously as anything else. You don't see the mental illness: It's not a mass; it's not a cyst. But it's there. Why do you need to prove it? If you can treat it, you treat it."

Seyfried also talked about how she was diagnosed for the condition. "I had pretty bad health anxiety that came from the OCD and thought I had a tumor in my brain. I had an MRI, and the neurologist referred me to a psychiatrist," she said.

The 30-year-old still feels insecure about herself at times even after continuing with her medication. "Sometimes I feel I know the world so well, but's so debilitating. You're like, 'What am I doing here? No one wants to see me. Why are you taking my picture?' It's stupid, it's irrational, and it's not all about me, but I make it about me because I'm insecure," the actress explained.

However, she added that a lot of her fears and anxieties have subsided with age. "As I get older, the compulsive thoughts and fears have diminished a lot. Knowing that a lot of my fears are not reality-based really helps."

In September, Seyfried and her Last Word co-star Thomas Sadoski got engaged after dating for a few months.

"Tommy and Amanda recently got engaged and shared the happy news with family and close friends," a source close to the co-stars told Us Weekly.