At times, watching actress Chloë Grace Moretz rub her temples with bewildered eyes can be a bit repetitive. However, the 95-minute movie depicting Cahalan’s month-long demise is very engrossing.

After all, how many stories show doctors diagnosing someone with a psychiatric disorder like schizophrenia, when, in reality, the patient is dying from a rare neurological disease?

Before Cahalan’s book,“ Brain on Fire: My Month of Madness,” came out in 2012, hardly anyone had heard of anti-NMDA receptor encephalitis. The disease occurs when the body’s immune system attacks NMDA receptors, or proteins, which control electrical impulses in the brain.

When NMDA receptors are damaged, judgment, memory, personal interaction, perception and autonomic functions like swallowing and breathing become compromised. And so it was for Cahalan.

"Brain on Fire" portrays Cahalan's erratic behavior, from hallucinating bug bites on her arm to inappropriately bursting out into laughter during an interview. Her editor, once impressed with her stories, finds her recent assignments to be unreadable.

People begin to wonder if she’s drinking too much or on drugs; certainly, she looks hungover.

Just when you’d think Cahalan’s behavior stems from a mental illness, she has an intense seizure. Her boyfriend rushes her to the emergency room, where doctors test her and send her home with antiseizure meds and a recommendation to stop drinking.

Unconvinced, she uses her journalism skills to researches her symptoms. She's unable to concentrate, eat or sleep, leading a self-imposed diagnosis of bipolar disorder.

But Cahalan indicates no prior history of mood swings, and her new psychiatrist gives her a prescription for an antipsychotic.

Within hours of taking the new drug, Cahalan begins screaming about how the side effects are making her crazy. Her perception of reality disintegrates so intensely that she believes her dad is trying to kidnap her. That’s when her (divorced) parents admit her to a hospital, from which she tries to escape. 

After a battery of tests, including neurological exams, autoimmune indicators, blood work for infection, and toxicity and metabolic workups, Cahalan shows no abnormalities. Doctors settle on a “likely” diagnosis of schizophrenia and suggest moving her to a psychiatric hospital. 

But her boyfriend knows: “she’s still in there; she’s just trapped; when I look into her eyes I can see she’s just screaming to get out." Her mother insists on further tests. Fortunately, one of Cahalan’s doctors consults her former professor, Dr. Souhel Najjar.

When Najjar asks her to draw the face of a clock, she slowly constructs a messy oval and writes all twelve numbers... on the right side.

Najjar recommends a brain biopsy to confirm his suspicion that her right hemisphere is inflamed. He explains to Cahalan’s parents that her brain is “broken … on fire.”

“No one with a psychiatric disorder would draw a clock like this,” he said in the film, explaining that her right hemisphere is inflamed, making her visual perception lopsided.

Najjar successfully treated her, but she had to re-learn many life skills from scratch, including how to write, walk, talk and smile. Cahalan also re-learned how to be a daughter and a lover to her partner.

"I had to learn how to exist again,” Moretz said.

Cahalan was the 217th person to be diagnosed with anti-NMDA receptor encephalitis.

“I’m the lucky one,” Moretz narrates as the movie comes to a close. Speaking as Cahalan, Moretz describes how “the system is designed to miss people like me."

"How many people do you think throughout history," she added, "were diagnosed as schizophrenic, psychotic, bipolar, or maybe just plain crazy, when they had something that could have been so easily diagnosed?” 

Najjar opened one of the first clinics in the world devoted to treating complex autoimmune brain disorders: The Autoimmune Brain Disorder Center at Lenox Hill. He and Cahalan remain close friends, and Cahalan continues to raise awareness about physical brain disorders and the treatment of mental illness.

Cahalan released her latest book, “The Great Pretender,” in November 2019. Thousands of people have since been diagnosed with anti-NMDA receptor encephalitis.

Stream the film on Netflix.