Noah Cyrus had "one of the hardest years". Picture: AP

Noah Cyrus had "one of the hardest years" of her life in 2018 after being gripped by anxiety and depression.

The 19-year-old star has spoken candidly about the difficult period in her life that led to her writing her song 'Lonely' and called for people to speak openly about their mental health issues.

In a new PSA video for 'Seize the Awkward', she said: "I felt stuck in this place that I could not get out of..

I just needed to get it out; I needed the conversation because I couldn't take it in my body anymore, I couldn't take the feeling of anxiety circling in my chest. I couldn't take that anymore, or I was gonna explode."

Noah's turning point came when she received a kind phone call from her manager.

She recalled: "One day my manager called me, and he said 'I just talked to a friend for a really long time, and I now understand what you're going through, and I'm here for you if you need me.'

"And that shifted everything for me, just knowing that one person on my team understood."

The 'July' singer encouraged people who are not experiencing such problems to open up to those who need to talk and wants to be able to help others as much as she can.

She said: "Sometimes I don't know how to solve the problem -- I'm only 19, I don't know how to solve a problem, I'm a baby.

"But if somebody's struggling emotionally, I can come and help. I feel like that's my strength. I'm not gonna be able to ace a math test, but I can help someone out who's hurting or feeling the same emotions as me."