A moving new memoir about spitfire Swedish climate change activist Greta Thunberg and her family painfully delves into a troubled past when she stopped speaking and eating.

When Thunberg was 11 and in fifth grade, she “cried at night when she should have been sleeping. She cried on her way to school. She cried in her classes,” her mother, Malena Ernman, writes in “Our House Is on Fire: Scenes of a Family and a Planet in Crisis.”  

“We tried our best, but nothing helped. She was slowly disappearing into some kind of darkness, and little by little, bit by bit, she seemed to stop functioning,” according to excerpts of the book available on Amazon. 

“She stopped playing the piano. She stopped laughing. She stopped talking …. She stopped eating.”

Thunberg, who soon appeared to be on the brink of starvation, was later diagnosed with Asperger’s syndrome and obsessive-compulsive disorder. But part of the trigger for her mental health crisis that year — as well as the drive for her eventual recovery — was a video about climate change she saw at school, reports The Washington Post.

Thunberg, now 17, was searingly affected by what she learned. Eventually, an almost single-minded focus to do something to help mitigate climate change helped inspire a worldwide movement. She became Time magazine’s 2019 Person of the Year and was nominated for a Nobel Peace Prize. She spoke at the United Nations and determined it would be a “waste of time” to speak to US President Donald Trump. 

She and her family view her autism as both a challenge and a clarifying strength in her mission against climate change. “Neuropsychiatric functional impairments” can be a “superpower, that out-of-the-box thinking you so often hear performers, artists and celebrities talk about,” Ernman writes, reported the Times of London. “Greta has a diagnosis. It doesn’t rule out the fact that she’s right and the rest of us have got it all wrong.”

When Greta first found out about climate change, she recalls, “I remember thinking it couldn’t be true. Because if it were, we wouldn’t be talking about anything else.”

The book is due out on Tuesday. Ernman, Greta, her dad, Svante Thunberg, and her sister, Beata Ernman, are all authors.