Camilla Nord, neuroscientist: ‘Being sad is normal, but depression is debilitating’

Camilla Nord, 36, directs the Mental Health Laboratory at the University of Cambridge, where she is a professor of cognitive neuroscience. Bearing a certain resemblance to a grown-up Hermione Granger, she greets us between classes in a glass-walled office overlooking a garden, in which squirrels dart around. Nord was born in France and raised in Washington, D.C., the daughter of an American father and a Dutch mother, as evidenced by an accent that is difficult to pinpoint. In her book The Balanced Brain: The Science of Mental Health (2023), she argues three points: that there is no single cure for depression, that medications are not as harmful as many people claim, and that the nervous system strives for stability throughout life, a stability that, unfortunately, will always be difficult to achieve.

Q. This morning at Tate Britain, I saw a painting by Ithell Colquhoun titled Depression: a bundle of stretched and tangled threads. Does that say anything to you?

A. It says a lot to me. It describes depression’s cage: the feeling of not being able to escape. But that door can be opened. There are always ways out, even if they’re not the same for everyone.

Q. Unlike other experts, you don’t pick sides: you accept multiple treatments and consider most of them valid.

A. A single treatment doesn’t work for everyone. Research shows the opposite: disorders are diverse, causes are multiple, and therefore there must be several ways to treat them. Scientists are already past that stage. Now we need to explain it better to the public.

Q. Some people use depression as a synonym for sadness. How do you respond to that?

A. Depression is a profound alteration of emotional — and partly physical — experience that impairs basic functioning. We need to distinguish normal variations in mental health — because we don’t have to be happy all the time — from illness, which requires treatment to restore those functions. Being sad is normal, but depression is debilitating.

Q. There’s a lot of distrust about the relationship between scientists and the pharmaceutical industry.

A. It’s a legitimate concern, born of biases, the concealment of adverse results, and the unfair promotion of certain drugs. I don’t collaborate with industry, though I know of solid work funded by pharmaceutical companies. We shouldn’t exclude medications, but neither should we make them the only path. Biology can also be modified by experiences and habits.

Q. You argue that having a coffee in the sun or laughing at a movie can act on the brain in a way comparable to a drug.

A. Our experiences change how the brain works. There are lovely studies: watching a comedy with friends activates the endogenous opioid system and raises the pain threshold. Its effect resembles, on a smaller scale, that of an analgesic. It shows there can be common biological roots via different routes: the pharmacological one, of course, but also the experiential.

Q. Spain is among the European countries with the highest number of mental health diagnoses. Why do some countries have more cases of depression than others?

A. There are large geographic and temporal variations. Part of it is explained by access to care: the more access, the more diagnoses. But, given equal access, environmental factors — poverty, perhaps pollution — small genetic differences and, above all, different cultural expressions of emotion play a role. Different cultures express distress in different ways, so even psychiatric disorders can differ somewhat depending on their cultural context. Stigma also matters: where there’s more shame, there are always fewer diagnoses.

Q. Are we more depressed today, or do we just talk about it more?

A. There’s no definitive answer. Part of the visible increase is due to better access. But there are also signs of a slight decline in well-being, especially among young people. Greater awareness has a flip side: it encourages monitoring symptoms and attributing them to the clinical realm, when sometimes they’re the normal ups and downs of life. On the other hand, the state of the world has an impact. The pandemic harmed mental health, and so do the climate crisis or the proximity of war, especially among young people, though this still needs to be confirmed at the population level.

Q. You study the balance of the nervous system. What is a stable brain, and how do you achieve it?

A. The brain constantly readjusts. It’s a predictive organ that aligns what’s lived and what’s expected with the environment to maintain homeostasis — the body’s ability to keep internal conditions stable despite external changes. We don’t achieve brain equilibrium once and for all. We’re obliged to readjust it throughout life.

Q. Electroshock therapy has a bad reputation. You say that, unfortunately, it works.

A. I hesitated to include electroconvulsive therapy because of its dark history, but the data show great efficacy in the most severe cases of depression. The problem is side effects, especially on memory. But models don’t point to brain damage, and cellular increases have even been observed in specific areas. Still, if someone experiences memory loss, that must be taken very seriously. That’s why it’s reserved for cases where no other solution has worked, always with consent and close follow-up.

Q. The hypothesis that medications compensate for a serotonin deficit has been discredited, yet you maintain that antidepressants work in about half of patients. How do you explain that?

A. During the second half of the 20th century there was misleading marketing: people spoke of correcting that supposed deficit without sufficient evidence, and adverse effects were downplayed. Even so, those medications work for many people, without a clear explanation. I wouldn’t dismiss them — but not because they correct a supposed deficit. Rather, because they alter how we process the ambiguity of certain emotions, which we can decode as good or bad.

Q. How do antidepressants act if they don’t correct a deficit?

A. By changing serotonin levels — without any need for a prior deficit — they alter the processing of emotional signals and shift us toward a more neutral or positive stance. They don’t lift your mood all at once; they adjust the bias with which we interpret those interactions and ambiguous signals. It’s like changing the filter you look through.

Excluding medication isn’t the solution. There are people who, after trying everything, climb out of the hole thanks to a drug. I believe they should be able to access it

Q. What do you say to people who oppose overmedication and quick diagnoses?

A. I understand: with health systems so overstretched, prescribing is more immediate than offering psychotherapy, which requires time and resources. I would also prefer more tailored decisions, but excluding medication isn’t the solution. There are people who, after trying everything, climb out of the hole thanks to a drug. I believe they should be able to access it.

Q. You dedicate the book to your daughter and your wife, and open it with a scene from your wedding. Why expose yourself so much, something many scientists avoid?

A. In my scientific papers, I never talk about myself. In the book I wanted to open up the world of those of us who do science: why we think what we think, where the vocation comes from, and when we change our minds. If I wanted people to look at the world like a scientist, I had to show a bit of who’s doing the looking.

Q. Have you experienced depression yourself?

A. I haven’t, but people very close to me have. Perhaps that’s why I’m obsessed with understanding it. A luminary in the field, Nolan Williams, recently died by suicide. It was devastating. It reminds us that, however close we may be to science’s solutions, it’s never enough to face a depression.

Q. Would you be a better scientist if you had been depressed?

A. My science would be worse if I didn’t work side by side with those who have lived it, or if I didn’t listen to them.

Q. And lastly: I hear that you’re a big fan of Buffy the Vampire Slayer. Did it influence you?

A. For me, it’s an ethical model: doing the right thing and thinking of the common good, even when it doesn’t benefit you. In academia, you can advance at others’ expense. Running a lab entails receiving credit for work that is always collective. I try never to put myself before the team. You can be both successful and supportive.

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