The 35-year-old Frozen star was in her teens when the mental disease first took hold, and she turned to her mother for some life-changing advice.

In a new essay published on Time Magazine's website Motto on Tuesday (31May16), Kristen writes: "When I was 18, my mum sat me down and said, 'If there ever comes a time where you feel like a dark cloud is following you, you can get help. You can talk to me, talk to a therapist, talk to doctor. I want you to know that there are options'."

The advice helped her when she suffered a low while studying at New York University.

"I’m so thankful for her (mother's) openness on this predominantly silent subject because later, when I was in college, that time did come. I felt plagued with a negative attitude and a sense that I was permanently in the shade."

Kristen could not understand the sudden depression she felt in her late teens and early 20s, because there was "no logical reason" for her to feel down. To work through her issues, she started speaking with a psychotherapist, something she still does to this day.

"Here’s the thing: For me, depression is not sadness," she shares. "It’s not having a bad day and needing a hug. It gave me a complete and utter sense of isolation and loneliness. Its debilitation was all-consuming, and it shut down my mental circuit board. I felt worthless, like I had nothing to offer, like I was a failure."

Kristen admits she stayed silent on her battle with depression for the first 15 years of her career, but after achieving worldwide fame, she believes it's her duty to speak out in an effort to remove society's "extreme stigma" surrounding mental health issues.

"It’s a knee-jerk reaction to judge people when they’re vulnerable," she states, "but there’s nothing weak about struggling with mental illness."

Kristen urges people battling with mental health issues to speak up and seek help.

"In order for all of us to experience the full breadth of team human, we have to communicate," she stresses. "Talking about how you’re feeling is the first step to helping yourself. Depression is a problem that actually has so many solutions. Let’s work together to find those solutions for each other and cast some light on a dark situation."