Sophie Turner had therapy to help her with her mental health.

Sophie Turner for Marie Claire Australia

Sophie Turner for Marie Claire Australia

The 'Game of Thrones' star struggled with mental illness after a change in her metabolism meant she gained weight and she found it hard to deal with the negative comments made about her online.

She said: "I have experienced mental illness firsthand and I've seen what it can do to the people around [the sufferers] as well. My metabolism suddenly decided to fall to the depths of the ocean and I started to get spotty and gain weight, and all of this was happening to me on camera."

And asked by Marie Claire Australia for their June issue what helped her overcome this, she added: "Therapy. Everyone needs a therapist, especially when people are constantly telling you you're not good enough and you don't look good enough. I think it's necessary to have someone to talk to, and to help you through that."

Sophie had previously credited therapy for changing her life.

She said: "I'm just a nervous wreck at the moment ... Depression for sure, anxiety, all of those things. I still experience it, but I had therapy, I'm on medication, and I feel so much better. The fact that I spoke to someone changed my life."

And the 23-year-old actress says her now-husband Joe Jonas has helped her find her "happiness".

She said: "I think for the longest time I didn't have a real sense of myself. I had a bit of an identity crisis where I was playing all these people and I'd grown up faster than I probably should have done. I hadn't been able to experience university, or just spend a lot of time with friends, so for a while, I kept thinking, 'Who am I?' A lot of [my happiness now] is to do with being with a person I've fallen in love with, who loves me more than he loves himself, and who wants to see me find my own happiness. That was probably the biggest thing that pushed me to find who I am - and find my happiness in things other than acting."