(Photo: David Senior/Pacific Standard)

As a five-year-old growing up in New York, Eric Finzi studied his mother’s face. She had a troubled, stormy, unpredictable mind, and he looked to her forehead to tell him what kind of day she was having. When her frown etched an omega-shaped collage of wrinkles on the bridge of her nose, or when the shadow cast by her brows darkened her eyes, he knew her depression was worse.

Finzi grew up and became a doctor specializing in dermatological surgery. In his spare time, trying to understand his mother, he read about psychology and mental illness, and he painted. Over the years, his mother’s condition worsened. When Finzi was 36 years old his father died, and his mother plunged into a depression so severe Finzi feared he’d never reach her again. He was right. She suffered—her glabella etched, her brow furrowed—until she died at the age of 74.

Soon after his mother’s death, Finzi painted a series of portraits from photographs of French women who had been institutionalized in the 19th century. By this point in his life, Finzi was a face expert. He spent his days in his dermatology clinic scrutinizing frown lines and injecting Botox, a paralytic, into the procerus and corrugator supercilii, the frown muscles beneath the glabella. Something about the French women’s expressions reminded him of his mother, and he began to wonder about the connection between expression and feeling—in particular, between expression and depression. Could the two be separated? Could eliminating the face of suffering help eliminate the suffering itself?

Finzi began musing on the facial feedback hypothesis, which holds that physical expression is an integral component of emotion. You can feel sad or angry without moving your face, but, the theory holds, those emotions will not be as strong or persist for as long if your face is not moving in the expected manner. Put another way, relative to emotion, the face and its muscles are a privileged area of the body. Whatever you do with your face transmits feelings back to your brain.

In 2003, Finzi treated several subjects suffering from moderate to severe depression with Botox, paralyzing the muscles in their brows that create expressions of sadness, anger, and fear. The results were astonishing.

At the time Finzi was painting the institutionalized French women, no one had tested the facial feedback hypothesis in conjunction with depression treatment, because no one had yet devised an effective experiment. How could a researcher know if a possible frown-inducing thought had gone unmanifested? After all, expressions begin under the skin. But Finzi realized he had a solution right in his hands, at least during his workday: Botox. If he could find a group of patients who were depressed and inject some of them with Botox, he’d be able to see, if any among them went into remission, whether paralyzing the brow helped eliminate or decrease their depression. So in 2003, Finzi launched a small pilot study. He treated several subjects suffering from moderate to severe depression with Botox, paralyzing the muscles in their brows that create expressions of sadness, anger, and fear. The results were astonishing. Nine out of 10 patients reported a complete remission of their depression.

The study was published in the Journal of Dermatological Surgery in 2006 to widespread incredulity and a few late-night talk show jokes. Despite Botox’s proven value beyond smoothing wrinkles—it’s known to help alleviate headaches, excessive sweating, even bladder incontinence—it’s still mostly associated with vanity. Then, in May 2014, in the Journal of Psychiatric Research, Finzi published the results of a second, much larger study, this one double-blind and randomized, with the results co-authored with Dr. Norman Rosenthal, a professor of psychiatry at Georgetown Medical School. (The project was also funded by Finzi’s clinic.) The study found a 47 percent reduction in scores on the Montgomery-Åsberg Depression Rating Scale among those injected with Botox. The members of the control group, who were injected with saline, exhibited a 20.6 percent reduction.

AS A LOS ANGELES woman who, perhaps, has her own share of wrinkles and her own share of depression, I found this intriguing. I have a big smile, a hard frown, and eyebrows that dance all over my face. No one has ever accused me of being stoic. Over the years, I’ve found peace in therapy and, on occasion, in antidepressants. I liked the idea that a person could Botox away her frown lines and feel better, but it also raised a serious question: If your feelings are written all over your face, what happens when you erase them?

The facial feedback hypothesis isn’t new. It goes back to Charles Darwin, who believed the “outward signs of an emotion intensifies it” and “the repression, as far as this is possible, of all outward signs softens our emotions.” The psychologist William James agreed: “Refuse to express a passion, and it dies.” The idea is that you’re not just frowning because you’re sad; you’re also sad because you’re frowning. Emotions aren’t emotions at first; they’re thoughts, and the physiological reactions to those thoughts shape and magnify how we feel.

In the 1970s, psychologist James Laird performed a clever experiment: He tricked people into animating smile muscles or frown muscles without implying any sort of emotion, and they reported feeling happier when a smile was enacted, and sadder when a frown was. In regular life, Laird told me recently, “The free expression of emotions increases the strength of the feeling.” Conversely, he said, “Reducing the expression is one way of reducing or perhaps even completely halting a feeling.”

But some believe the results of Laird's experiment have been misinterpreted or overblown. “Most of the important emotions don’t even occur on the face,” says Jerome Kagan, a pioneer in developmental psychology and the author of The Human Spark: The Science of Human Development. “Guilt doesn’t appear on the face. Lust doesn’t. People who have Bell’s palsy, a state where the facial muscles are paralyzed, report all these emotions.” He sees the idea of facial feedback as “just an old theory from Darwin, made popular by Paul Ekman”—the former University of California-San Francisco psychiatry professor and leading authority on the connection between expression and emotion—“and it’s just not true.”

BETTER LIVING THROUGH FACIAL paralysis? I decided to give it a try, making an appointment at my local Botoxerie during a moderate depression in which my face was hiding nothing. I normally do an OK job of masking my depression with exuberance, but I had sunk to the point where my husband would look at me and sigh. I began wondering if my children, like little Eric Finzi, were scanning my face to take my emotional temperature. I knew Botox could mask my feelings from those who encountered me, but could it mask them from myself as well?

THE BOTOX ARTIST: Dermatologist Eric Finzi noticed a resemblance between the unhappy faces of his portrait paintings and the unhappy face of his mother. It made him wonder if medically preventing melancholy expressions could prevent melancholy feelings.

Within a week of administration, the Botox began to kick in. I’m not the first person to get Botox, so I’ll spare you the wide-eyed details, but it was pretty strange. At the beginning, I could still move my brow, but it felt increasingly heavy, until I was no longer able to lift it. I felt like I’d received a facial epidural. It was the emotional equivalent of wanting to sneeze but not being able to.

By two weeks in, I had no real recollection that I had ever been able to move my eyebrows. You might as well have asked me to shrug my fingernails or flare my hair follicles. What surprised me most was the number of people I know who get Botox regularly, none of whom ever thought to say, “I tell you, it’s really great because you can’t see any flaws on your forehead—but it’s crazy the way you can’t move half of your face.”

Having read Finzi’s studies, I expected that the emotional impact of the Botox would be internal—that I would feel different inside. But I also noticed a reaction to the Botox in the people I encountered. My mother had always told me that if you’re not frowning more people will want to talk to you, and she was right. As David Matsumoto, a professor of psychology at San Francisco State University and a renowned expert in expression, says, “If your expression changes, then of course how people are perceiving you will change.” Finzi once told me about an older female patient of his who hadn’t socialized in years because of her depression. After Botox, she felt well enough to attend her high school reunion and ended up in a relationship with her high school boyfriend.

But paralyzing the brow doesn’t just eliminate a person’s ability to frown, thereby causing that person to make a cheerier impression. It takes away a key communication tool—facial postures are called expressions for a reason—and this interferes with the ability to empathize. If you were telling me a sad story, my face typically would reflect the expressions on your face. My eyebrows would knit together and rise, even if only slightly; my lip might jut out a little. Those reactions, created by what are called mirror neurons—the neurons responsible for reflecting the expression, and therefore the mood, of the person you're interacting with—wouldn’t just tell you that I was listening. They would help me feel what you were feeling.

I liked the idea that a person could Botox away her brow lines and feed better, but it also raised a serious question: If your feelings are written all over your face, what happens when you erase them?

“Empathy and social communication are such delicate things that they break down very easily,” says Dr. Marco Iacoboni, a professor of psychiatry and bio-behavioral sciences at the University of California-Los Angeles and the author of Mirroring People: The Science of Empathy and How We Connect With Others. “If you can’t respond with your face to other people with emotion, that will become a vicious circle.” People will believe you are detached or don’t care. In fact, in animated films, faces look inhuman and horrifying when they don’t move as we expect—particularly when the forehead doesn’t react as expected in emotional situations. A detached-looking mien may be a problem for treating depressed patients with Botox. “They are already so wrapped up on themselves,” says Iacoboni, disconnected from the world. One of the last things they need is a treatment that socially isolates them further.

But I found Botox wasn’t all bad. After my injections, the too-cool people at the coffee shop where I sometimes work began to smile at me, perhaps because I seemed less needy. I went to a SoulCycle class, and presumably because I could no longer knit my eyebrows in the face of suffering, I had an uncharacteristically easy time. The next day, I did my first Pilates class. Pilates, reader. Botox!

But then a friend who, last year, following years of harrowing fertility treatments, had a stillbirth, told me she was pregnant again. I knew this was good news. I smiled. I assured her that I was elated, even though the truth is I was only sort of thrilled. I couldn’t feel the same depth of joy I would have a few weeks prior. When she raised her eyebrows and twisted them in the relieved sadness that comes with good news that recalls bad, I could only watch, a step removed, using words I hoped were emphatic enough to convey how pleased I was for her.

This detachment persisted for the four months that the Botox remained active. Recognizing news as happy isn’t the same as feeling joy. Sure, I appreciated not becoming emotional at a contentious parent-teacher conference. (Often I tear up, eroding respect from the other side.) But I also didn’t feel the expected level of worry when my children cried out in pain. I cared for them, of course. But I was cut off from feeling the hurt they felt. Even movies that would have hooked me emotionally seemed to be dubbed over in a language I couldn’t be bothered to understand. More disturbing: My friends (and husband! and children!) stopped reacting as they usually did to me, making our interactions feel leaden and boring. Ironically, the flatness mirrored that of my worst depressions. My children, whom I’d once been so worried I was traumatizing with my sad expression, were confused by my lack of one.

As the weirdness subsided, I realized I wouldn’t characterize myself as less emotional with the Botox. I had the same emotions I'd always had; I just didn’t care about them. And then I wondered what this meant. We are our feelings, after all. The rest is just blood and tissue. I felt diminished by feeling less deeply, and that, to me, was the most compelling result. We think that the opposite of depression is elation, but that isn’t exactly correct. Happy people don’t walk around ecstatic the way depressed people walk around sad. No, the opposite of depression is the absence of depression—and I suppose, in those terms, the Botox worked. I did experience an absence of depression. But Botox also took away other feelings, the ones we need to make us whole: joy, jealousy, frustration, triumph. Feeling leap-in-the-air excited—that was gone, too.

My Botox did wear off, first on the left side, then the right. By the time my friend’s baby was born and she posted pictures to Facebook, I was able to smile-cry for a good, long time—primarily with true joy for my friend, but also with relief for myself; relief that I was still here, alive and feeling. I walked to the bathroom, looking for tissues, and saw in the mirror the same face I’ve always made, the one Finzi saw on his mother all those years ago—lined, expressive. I watched this face in the mirror, my most human one, and I promised myself it would be OK.

This post originally appeared in the July/August 2014 print issue ofPacific Standardas “Botox Nation.” Subscribe to our bimonthly magazine for more coverage of the science of society.