Susannah Cahalan was moving up in the world. As an ambitious young reporter for the New York Post, she had a bright career ahead of her. She was in a new but serious romantic relationship. And she was renting a Manhattan apartment on her own, a point of pride signalling she had reached adulthood and independence.
But at the age of 24, Cahalan suddenly and frighteningly began losing her mind. She became disoriented and paranoid and suffered hallucinations and seizures. Doctors were at a loss to explain what was wrong, blaming mononucleosis, bipolar disorder and even drinking and working too hard. Meanwhile, Cahalan spiralled further into psychosis, eventually winding up in hospital for a month – at times, strapped in bed to restrain her deranged outbursts – with no recollection of her time there.
She was lucky. A prominent neurologist, Souhel Najjar, took an interest in her case, identifying her illness as a newly discovered autoimmune disorder called anti-NMDA-receptor encephalitis, a condition in which the body attacks the brain. In 2009, Cahalan was only the 217th person in the world to be diagnosed with the disorder. Since then, thousands have been found to have the same autoimmune encephalitis, raising questions about how many more cases go undetected, mistaken for schizophrenia, autism or other mental disorders.
Although what triggered her autoimmune reaction remains a mystery, Cahalan was treated and recovered. By poring through her medical records and interviewing her doctors, family members and friends, she pieced together the events she lost and wrote a book, Brain on Fire: My Month of Madness.
Speaking by telephone from her home in New Jersey, Cahalan told The Globe and Mail what it was like to descend into insanity and return.
How much do you remember about the onset of your illness?
Before being hospitalized, I do remember a good portion. I remember thinking I had bedbugs. That was kind of the first sign – a sign I didn't think much of because everyone was afraid of having bedbugs at the time. Then I had tingling and numbness in my left hand, which was very disconcerting. And then I had migraines, but I was told I had mono.
Then the other psychiatric symptoms came up: I was paranoid, I was jealous, I was snooping through my boyfriend's things, I was moody at work. Mono didn't explain that, but we all go through ups and downs emotionally, and, at first, I thought maybe I was just going through that.
When you see yourself in video footage taken at the hospital or hear accounts of how you behaved, is there anything you recognize as you?
She's so far removed, and I say "she"; I really do look at myself at the time as another person. But I've seen the video several times now, and it upsets me and it unnerves me. So there's something there. If I was totally distanced from it, I wouldn't have that feeling watching it.
Do you wish you remembered more, or is it a mercy to forget?
When I was writing the book, I wished I remembered more. I really did. I tried to access those memories. But at the end of the day, so much of it was lost and I don't think I will ever recover it.
But I do run into things, like I recently found a deck of cards with which my dad and I used to play in the hospital. I'm not sure if I played with him actively, but it was a weird moment when I saw them and recognized them. So there are times when things emerge and remind me of things I thought I had forgot.
How concerned are you of a relapse?
One in five people will have a relapse, and unfortunately, that risk follows you your whole life. But you have the same percentage chance of getting better. So if you survive the first time, you'll survive the second time.
Even though you've recovered, you say you don't quite feel the same. How would you describe the change in yourself?
I've struggled with this question. I'm different now because my life is more stable, I'm not in my early 20s any more. So I don't know how much of it is getting older. But also, I went through something very profound, so it had to have changed me. The question is did it change me on a biochemical level? I don't know. If you talk to the experts, they are pretty much shocked I have retained my sense of self from prior to the illness.
What do you hope readers will take away from this book?
First of all, I wanted to get the disease out there. Another thing is there's still a really huge stigma attached to mental illness, whether it's manifested in psychiatric behaviour disorders or through an autoimmune disease. I hope this book will help destigmatize this in a way.
You lashed out at those closest to you while you were ill, something you wouldn't ordinarily do. What advice can you give to people whose loved ones are suffering from mental illness?
It's so hard because I was the one being cared for. I don't know how I would be on the other side. Psychosis is so hard to deal with because someone's so volatile, you can't expect what's going to come out of their mouth next.
But during my recovery when I was more catatonic, less psychotic – similar to anyone recovering from a brain injury or on anti-psychotic medication – you're still in there and you're still an adult. I remember being treated with kid gloves and people talking to me very slowly and deliberately, like I was a child. And that bothered me deeply. It's not even their fault. You think this person's not following what you're saying. But what I learned from my experience is I'd never treat someone like that. I just know how demoralizing that is.
How has the experience changed the way you think about mental illness?
What I've discovered from just studying the disease and the effect on the brain is, at the end of the day, there's no difference between me and someone with a mental illness and psychiatric disorder. There's no difference except I was cured.
More common than thought
Experts believe that anti-NMDA-receptor encephalitis, discovered in 2007, is far more common than initially thought. As awareness spreads, the disorder has surfaced in populations never before considered, including in children as young as two years old.
In those with the disorder, the body's immune system produces antibodies that target and inhibit NMDA (N-methyl-D-aspartate) receptors in the brain, which are responsible for allowing nerve cells to communicate with each other. This causes encephalitis, or brain inflammation, and disrupts proper brain function, including such things as cognition, personality, behaviour and emotions.
Neurologist Souhel Najjar, a leading expert at New York University, suggests that other autoimmune disorders, such as lupus, and medical conditions that cause inflammation may be to blame for some psychiatric disorders. For example, he says, diabetes and multiple sclerosis increase the risk of depression, providing evidence of a link. And over the past three years, researchers have discovered a rapidly expanding spectrum of autoimmune encephalitis, beyond the anti-NMDA-receptor subtype.
"They're way more prevalent than anybody ever thought," he says. "And the sad part of this is some of those patients end up with permanent neurological deficit, permanent psychiatric deficit and permanent cognitive deficit."
Some people wind up institutionalized in psychiatric wards or nursing homes, while others die undiagnosed or misdiagnosed.
So when should doctors and family members suspect autoimmune encephalitis? Najjar says patients should be tested if they experience a sudden onset of unexplained psychiatric symptoms, especially psychosis, and are unresponsive to treatment.
This interview has been condensed and edited.