Have you ever been gripped by the suspicion that nothing is real? A student at Stevens Institute of Technology, where I teach, has endured feelings of unreality since childhood. She recently made a film about this syndrome for her senior thesis, for which she interviewed herself and others, including me. “It feels like there’s a glass wall between me and everything else in the world,” Camille says in her film, which she calls Depersonalized; Derealized; Deconstructed

Derealization and depersonalization refer to feelings that the external world and your own self, respectively, are unreal. Lumping the terms together, psychiatrists define depersonalization/derealization disorder as “persistent or recurrent … experiences of unreality, detachment, or being an outside observer with respect to one’s thoughts, feelings, sensations, body, or actions,” according to the Diagnostic and Statistical Manual of Mental Disorders. For simplicity, I’ll refer to both syndromes as derealization.

Some people experience derealization out of the blue, others only under stressful circumstances—for example, while taking a test or interviewing for a job. Psychiatrists prescribe psychotherapy and medication, such as antidepressants, when the syndrome results in “distress or impairment in social, occupational, or other important areas of functioning.” In some cases, derealization results from serious mental illness, such as schizophrenia, or hallucinogens such as LSD. Extreme cases, usually associated with brain damage, may manifest as Cotard delusion, also called walking corpse syndrome, the belief that you are dead; and Capgras delusion, the conviction that people around you have been replaced by imposters.

I’m glad Camille has drawn attention to the disorder, because derealization raises profound philosophical questions. Sages ancient and modern have suggested that everyday reality, in which we go about the business of living, is an illusion. Plato likened our perceptions of things to shadows cast on the wall of a cave. The eighth-century Hindu philosopher Adi Shankara asserted that ultimate reality is an eternal, undifferentiated field of consciousness. The Buddhist doctrine of anatta says our individual selves are illusory.

Modern philosophers such as Nick Bostrom postulate that our cosmos is probably a simulation, a virtual reality created by the alien equivalent of a bored teenage hacker. The philosophical stance known as solipsism insinuates that you are the only conscious being in the universe; everyone around you only seems conscious. As I mention in a recent column, some interpretations of quantum mechanics undermine the status of objective reality. Could derealization have inspired all these metaphysical conjectures?

Many people, Camille suggests, undergo episodes of derealization without knowing what it is. The feeling disturbs you, so you suppress it. You try to put it out of your mind, and you don’t mention it to others. “You’re afraid that if you do tell people, they won’t know what it is,” Camille explains, “and you don’t want people viewing you differently.” I understand these reactions, because derealization can be unsettling, even terrifying.

My most serious, sustained bout of derealization occurred after a drug trip in 1981, which left me convinced that existence is a fever dream of an insane god. For months the world felt wobbly, flimsy, like a screen on which images were projected. I feared that at any moment everything might vanish, giving way to—well, I didn’t know what, hence the fear. These feelings over the years have lost their visceral power over me, but their intellectual aftereffects linger.

Pondering derealization leaves me conflicted. I have moral misgivings about claims that reality isn’t, well, real. These assertions, whether Platonism, the simulation hypothesis or my insane-god theology, can easily become escapist and nihilistic. Why should we worry about poverty, oppression, environmental destruction, pandemics, war and other sources of suffering if the world is just a video game? I reject any philosophy that undercuts our responsibility to care for each other.

I’ve nonetheless come to value derealization as an antidote for habituation. Our brains are designed to accomplish many tasks with minimal conscious effort. As a result, we get accustomed to things; we take them for granted. We become like zombies or automatons, carrying out chores and interacting with other people—even those we supposedly love—without being fully aware of what we are doing.

Derealization is like a slap across the face. It cuts through the monotony of life and wakes you up. It reminds you of the weirdness of the world, of other people, of yourself. By weirdness I mean infinite improbability and inexplicability. Weirdness encompasses all the bipolar properties of our existence, its beauty and ugliness, kindness and cruelty, good and evil.

Seeing the weirdness doesn’t negate our moral responsibility to others. Far from it. By estranging me from the world, derealization, paradoxically, makes it more real. It helps me see humanity more clearly and care about it more deeply. What once felt like a curse has become a gift.

That’s what I tell myself, anyway. Others, including those Camille interviewed for her film, and Camille herself, experience derealization differently. She sees the syndrome as “your brain’s way of taking a break. It thinks you can’t handle certain things, and so it turns everything off.” She has learned that “just letting the feelings flow” rather than fighting them helps her get through episodes. Whatever derealization means to us, however we cope with it, we’re surely better off if we can talk about it openly, as Camille and others do in her brave, revealing film.

This is an opinion and analysis article, and the views expressed by the author or authors are not necessarily those of Scientific American.