Deep brain stimulation has been used for years to diminish tremors in people with Parkinson’s disease, but it’s experimental and controversial as a treatment for psychiatric disorders.* Only a few OCD patients have undergone it (roughly two dozen so far in the current, FDA-approved study, and no more than a hundred in the U.S. total), and like many historical attempts to alter the mind, it seems halfway magical because no one really understands its mechanisms. Obsessive-compulsive disorder is not like Parkinson’s disease—the symptoms aren’t visible and physical (trembling hands) so much as experiential and behavioral—so neurosurgery-as-treatment becomes more existential in its implications. Compounding this is the fact that, neurochemically, obsessive-compulsive disorder bears a conspicuous resemblance to falling in love. Scientists have scanned the brains of the pathologically obsessive and held them up next to brain scans of the love-struck, and the images turned colors in the same places. Doctors drew blood and found the same chemical imbalances—namely, a serotonin deficit. The philosophical distinction between deactivating a part of someone’s brain and deactivating some part of their mind or self begins to blur.

  I’ve done months of research about deep brain stimulation—reviewing articles, deciphering studies, interviewing physicians, scrolling through procedure videos on YouTube—for no special reason other than what you might call—ahem—a persistent curiosity. While reading the literature, it’s easy to think in clinical abstractions, but then I watched a video of an older woman undergoing the procedure and was struck by the way her voice was muffled by the nest of equipment. The doctors kept having to ask her to speak up during the adjustment phase, when she was supposed to be reporting changes in her psychological state. “I said I almost just laughed,” she repeated, gazing at the equipment before her with an expression of wonder. “I haven’t laughed in . . . a very long time.” The doctor nodded dispassionately. “Can you describe that for us?”

  It seems important to cling to the concrete, to remember that illness is not a metaphor or a study but a phenomenon unfolding in (and on) real bodies in real rooms. Its qualia, the crinkly paper hospital gown and metallic adrenaline taste, the mutable and inexpressible shades of pain, demand articulation because they matter. We work so hard at telling others what it is like to be sick in whichever particular way we are sick; we are reassured to hear that our particulars fit within larger known narratives of illness. With sickness as with anything else, communicating what it is like so others can know, or understanding others in precisely the way they wish we could, is next to impossible. We try anyway.

  Admittedly, most OCD patients are not like my imagined girl. Usually, the disease is damaging but not devastating in a relationship-ruining, inpatient-care, life-disintegrating way. It is considered a less challenging diagnosis than, for example, bipolar disorder, schizophrenia, or any of the personality disorders.* It is “neurosis,” not “psychosis,” “mental illness” as opposed to “insanity.” The existence of the DBS study, though, and the interest it draws from patients and practitioners alike, subtly undermines this differentiation. Extreme treatment reflects the disease’s extreme power to cripple. Neurologically, OCD seems to act on similar parts of the brain as schizophrenia; experientially, both diseases are marked by foreign-seeming intrusions on the mind. Both patients are overcome with thoughts, images, and impulses that are, to use the clinical word, ego-dystonic: they feel alien to and in conflict with the self. They feel other. In obsessive-compulsive patients, these thoughts tend to be violent or violating, obscene, immoral, or some other shade of horrifying.

  What distinguishes obsessive-compulsive patients from schizophrenic patients is their ability to live inside a paradox: the thoughts hijacking their minds feel urgently not “theirs,” but the thoughts are nevertheless something going on in their own minds and bodies. These thoughts are alien, but they have not been planted by aliens. In the medical community, this is known as “insight.”

  Having insight is not enough to make the thoughts go away. A little while ago, I was talking to a writer who has to touch things—all the slats on the staircase, all the poles as he walks down the street. He knows this doesn’t make sense. Sometimes, though not terribly often, he has to go back home to make sure that he didn’t leave a cigarette burning, even when he can remember perfectly well that he didn’t. He only has to do this when alone. When he’s with people, he doesn’t have to touch anything.

  He told me that since childhood he’s been fascinated with the idea that everyone is God. I asked him what he meant, and he said that he had a suspicion that God was everywhere and everyone, and all our souls are the same soul, God’s soul, but we’re just walking around in different meat suits. That’s how he said it: “We’re all stuck in our own meat suits.”

  I suddenly felt very aware of how different he and I look—his height and beard and age, his ruddiness, his tie; my stringy arms, bitten nails, and freckles. He is older than I am, and bigger, and embodied in a sort of ragged, robust way that I am not. At first I couldn’t quite tell whether he was fucking with me when he leaned in and looked into my brown eyes with his blue ones and said, “What I’m saying is that maybe we’re all the same, we just don’t know it because we’re separated into our own bodies,” but then I decided that he was not fucking with me and was serious, at least partly, about this hypothetical.

  And part of me was thinking, Get a grip.

  Another part was thinking, Well, exactly.

  Which did not signal that I was on board with the meat-suit theory per se, only that I was not surprised, even a little, to discover another person with OCD who’d been worrying his whole life about the distinctions and correspondences between himself and other people, and between himself and God. You don’t have to have OCD or any mental illness to have concerns like this, but the urgency of locating the boundaries of the self, the distinction between what is inside and outside, you and not-you, becomes particularly acute when your mind seems a little too permeable.

  Obsession was initially a term of warfare. In Latin, obsessio indicated the first phase of a siege on a city, when the city was surrounded on all sides but its citadel remained intact. Obsessio was followed by possessio, when the attacker breached the walls and took the city from the inside. In Obsession: A History, Lennard Davis explains the way these two words were adapted to explain demonic possession in the third century: “In the case of obsession, that person was aware of being besieged by the devil since the demon did not have complete control, had not entered the city of the soul, and the victim could therefore attempt to resist.” Demonology was, for many centuries thereafter, the only language available for explaining obsession and other insanities. Obsession was understood as a torment of the soul and, often, a spiritual punishment. The cure was exorcism.

  This went on for more than a thousand years, until some Protestant churches began to retreat from the idea of possession (piqued at the way the Catholic Church had, per Davis, “the inside track on exorcisms”). In 1731, the English Parliament repealed laws banning witchcraft, which had been the most common grounds for exorcism. Modern medicine was in its nascent stages, and as it developed it annexed mental affliction, recategorizing madness as a physical rather than a spiritual problem. The demonological model was replaced by the medical model. Scientists discovered the nervous system and, with it, “nerves,” and the possibility of a physiological source of mental states.* Davis notes, “The nerves are the physical link to the mental—they are dissectible, discernible, and physical, yet their effects are metaphysical, symbolic, and affective.”

  In the same era, roughly the late seventeenth to early eighteenth century, the notion of “partial madness” emerged to accommodate people who were mentally ill but tethered enough to reality to recognize their illness or sane enough to function within society. One could be “a conscious ‘I’ who is watching an obsessed self instead of a deranged and unconscious self dwelling in a lunatic.” Sanity went from a binary category (sane/insane) to a triad:
you could be lucid, a lunatic, or a neurotic. The “monomaniacs,” as obsessives came to be known, were the stars of this new formulation. The monomaniac tended to be high functioning and highly thought of. Davis writes, “A certain cachet developed, a notion of being fashionable, in having one of these partial, intermittent conditions.” Neurosis was constructed as intrinsic to character, but as a possible asset. It was a sign of advancement, complexity, genius, cosmopolitanism, and, so to speak, heightened sensibilities.*

  Such was the case with Sigmund Freud’s most famous obsessive. The Rat Man, as Freud nicknamed him to protect his identity, was clever and charming, a successful professional man who was nevertheless ruled by disturbing fantasies of rodents attacking his father and fiancée. Freud, writing in 1909, took a therapeutic approach to the Rat Man that became typical for a time: the man’s problems were purely issues of the psyche. His obsessions stemmed from the fact that he’d been punished for masturbating as a child, and had formed as a defense mechanism against the anger, aggression, and anxiety he felt in his adult relationships. The cure: analysis.

  A hundred years later, we don’t think of the mind as something that can be entered, invaded, or deciphered so much as something that can be altered and adjusted. The mind is less the point, actually—Freud’s methods have become passé. Now we talk about the brain, which is not parametric in that our metaphors for it do not indicate that the brain has parameters that can be violated. Insanity is now more biological than spiritual. “Mental illness” is no longer a breach of the self but a neurochemical event happening to—but separate from—the self. Like hypertension, it happens in our cells, and we swallow pills to get rid of it.*

  This is more or less how grown-ups talked about what was wrong with me for several years after I was diagnosed with OCD at thirteen. I was, clinically, a nervous wreck, and many of my fears were about the transformation of my own mind. Was I insane? Was I doomed? Was this who I really was? Therapists and my parents were ready with reassurances that what was happening was only an accident of serotonin, a mysterious but correctable “imbalance” no more essential to who I was than a flu or a sunburn. I balked at taking medication, worried it would change who I was. “You have an illness, and this is just medicine to correct that illness,” I was told. “It’s like having diabetes. You wouldn’t refuse insulin because your body’s ‘authentic’ state is to have diabetes.” In the end, I couldn’t take the panic attacks, so I took the Prozac and, with it, this narrative of what was happening. It worked. The pills made my hands shake, but my mind was transformed back, more or less, to the healthy, stable state I remembered.

  When I was seventeen, not long after weaning myself off Prozac, I relapsed. It happened sort of slowly. The thoughts came back, but at first I could fend them off. I blew past them with the buoyancy of a teenager whose life was going well. I was a few months away from leaving for what seemed like the most exciting college in the world, and I had my first boyfriend. Gradually, though, I stopped being able to ignore the thoughts. They came too quickly, and one day they seemed to bring real danger with them. Something darkly magical began to happen: I would gaze out at sunny days, beach days, Southern California sunsets, and feel the sidewalks begin to warp. The sky was cloudless, but something was terribly wrong. This feeling would steal an hour one day, and then I’d be myself again. The next day, two hours. As weeks passed, the sinister entered, and sick fear took over.

  At the time I worked as a barista for a local breakfast-and-lunch place on the beach, pulling espresso and pouring green-tea lattes in an eight-by-eight-foot alcove off the restaurant’s kitchen. A wall obstructed my view of the line cooks, so I spent my shifts in isolation, handing cup after cup out a window the size of a cereal box to a man named Fernando who ate toast with whipped cream for breakfast. I’d be pouring cappuccinos and humming in my little wall-hole and then suddenly, as if from nowhere, a terrifying sentence would appear in my mind. Then another. Then a dozen. Panic attacks rolled in hourly. I began taping poems to the espresso machine to memorize, figuring that if I had to entertain thoughts that weren’t mine I might at least try to make them beautiful. I knew what was happening, but knowledge didn’t help. Diagnostic categories, the language of treatment—they weren’t enough. My teenage hair started to gray; my hands shook at the machine. I was growing desperate. One afternoon, I stepped into the back alley behind the restaurant, dialed my therapist, and told her that I thought I might not survive it.

  I was understudying Juliet that summer for a local production of Romeo and Juliet, which meant sitting in on rehearsals and learning the lines and blocking. This should have been fun and exciting—and it was some days, particularly when the handsome blue-eyed actor playing Romeo made a point of flirting with me. (The regular Juliet was sleeping with Mercutio.) But most days it felt like something was very, very wrong. People often describe the way your body senses instinctually that you’re in the presence of a sociopath or in physical danger. The feeling can be confusing at first, because your body is telling you something that your rational mind doesn’t yet know. Why do I feel so unsettled and skin-crawly when she’s so nice? This party is so fun; why do I feel like I have to get out of here? I spent benign afternoons in rehearsal forcing myself not to bolt from the room. The theater, the restaurant, my bedroom—every place seemed menacing and uncanny. I spent hours in complex, circuitous rationalizations and self-assurances that boiled down to, in endless repetition: “But nothing’s wrong, but nothing’s wrong, but nothing’s wrong.”

  Of course, something was wrong. The imminent danger was my misfiring sense of imminent danger, the revelation that the stability and habitability of the world can change as the mind changes. Minds are not reliably stable or habitable. They are subject to radical and sometimes horrible transformation. This is a danger of the world that is, as I was discovering, intangible but absolutely real.

  Juliet has a monologue in the fourth act, spoken alone in her bedroom as she prepares to take a potion that will plunge her into a sleep so profound she’ll appear dead. She and Romeo have agreed that she’ll drink this potion, and once she’s been mourned and entombed in the family mausoleum he’ll come to wake her, and they’ll sneak out of Verona under cover of night and begin their life together. She’s resolved, even impatient, to go through with the plan and reunite with Romeo, but as she uncorks the vial, a thought occurs to her. “What if it be a poison, which the friar subtly hath minister’d to have me dead?” Fairly quickly she dispenses with this anxiety (the friar is a holy man and a trustworthy friend), but another pops up to fill its place: What if she wakes up before Romeo arrives? What if she suffocates in the tomb? Her nervousness takes on a tinge of panic. What if, worse yet, she wakes too early but does not suffocate, and is left alone in the vault “where, for these many hundred years, the bones of all my buried ancestors are packed: where bloody Tybalt lies festering in his shroud?” Then she strikes on the most frightening thought: what if she, surrounded by bodies and smells and “shrieks like mandrakes torn out of the earth, that living mortals, hearing them, run mad,” is so overwhelmed that she loses her mind? Will I “madly play with my forefathers’ joints,” she wonders,

  And pluck the mangled Tybalt from his shroud?

  And, in this rage, with some great kinsman’s bone,

  As with a club, dash out my desperate brains?

  O, look! Methinks I see my cousin’s ghost

  Seeking out Romeo—

  Quickly, she is hallucinating with panic. The loss of her own mind, imagined in the grotesque vision of herself fondling dead bodies in the dark, is made real by her own terror. The figure of Tybalt rises before her to kill Romeo. Desperate to make Tybalt—and the vision—stop, she seizes the potion bottle and, in a gesture that’s not a little suicidal, swallows it all. She collapses. End scene.

  I dreaded this monologue, but I memorized it, made notes on it, even diagrammed it. I was convinced that the young woman playing Juliet, beautiful as she was in the balcony scene
, failed to capture this movement from nervousness to wild, unhinged fear. But I also hoped I’d never have to perform the scene myself. It felt too close. Acting demands letting go of the self in a way that is usually considered self-destructive or pathological in real life; acting demands that you make way for other selves.

  But then there’s the trick of coming back, of reconstructing the boundaries between your mind and your character’s mind. Sometimes this is hard to do. There are characters you don’t want to play because you know they’ll be frightening to expand into or difficult to come back from.

  That summer when I was feeling very much like Juliet holding the potion, the therapist would tell me, “Just know that those thoughts aren’t you. That’s the OCD, it’s not you.” It was a kind gesture—she was offering me the illness narrative that reigns now, the one that constructs very, very firm boundaries between brain and self, illness and consciousness, self and other. I clung to that for a while, the notion that the maelstrom happening in my brain was not of me but outside me, happening to me. That there was a tidy line dividing “me” from “disease,” and the disease was classifiable as “other.” But then it became difficult to tell whether certain thoughts should go in the me box or the disease box—where did “I want to throw a rock through the kitchen window” belong? Eventually I could no longer avoid the fact that mental illness is not like infection; there’s no outside invader. And if a disease is produced in your body, in your mind, then what is it if not you?