Neuroscientist Dr Camilla Nord is reassuring me that it does not hurt – the electromagnetic pulses about to be zapped through her brain just feel like a strong tap on the head – over and over. When the machine is placed at the front of the brain, over the motor cortex, the pulses have the power to move her fingers. But when placed over the dorsolateral prefrontal cortex, the part of the brain that controls emotion, she believes they can do so much more.
This treatment is transcranial magnetic stimulation (TMS), and in the near future, Dr Nord thinks it might cure your depression. This year, the NHS announced that the new therapy would be rolled out in the west of England to treat those with severe depression. Previously, sessions were only available in private clinics and could cost a patient about £40,000.
This innovative type of brain therapy goes to the heart of Nord’s research. As a brain scientist at the University of Cambridge’s MRC Cognition and Brain Sciences Unit, Nord leads the Mental Health Neuroscience research programme. During her 10-year career researching the complexities of how the brain makes us feel, she believes we have fundamentally misunderstood depression. “We’ve been trying to find a single underlying biological cause,” says Nord. “If that’s what we were trying to do, we have failed.”
Nord’s laboratory researches the science of TMS, and its ability to combat depression. The electromagnetic tool acts like a gun to the brain, stimulating the nerve endings which can reduce symptoms of depression. “TMS is shallow and actually mostly only targets the outer regions of the brain,” says Nord. “That type of simulation typically takes several sessions for someone to feel better, a bit like if they have taken an antidepressant.”
A typical patient might have five sessions of TMS a week for several weeks but each session would involve 500 taps. For some, this therapy is revolutionary and its effects can be felt for several months. For others, it might be a waste.
“I don’t think there will ever be a silver bullet for mental health conditions that can combat all types of depression,” says Nord. “Each mental health condition is far too diverse and far too heterogeneous to have a single underlying cause or a single potential treatment.”
Not having a single cause isn’t necessarily bad news. Nord – who has written a new book, The Balanced Brain: The Science of Mental Health – believes that if there are many causes for poor mental health, then there are many ways to fight it. “Even if the latest, coolest treatment you’ve read about, whether that’s psychedelics or probiotics, doesn’t work for you. That doesn’t mean nothing else will,” she says.
The rate of depression is growing in the UK: 17 per cent of adults experienced depression in the summer of 2021, compared with 10 per cent in 2020, according to the Office of National Statistics. Despite the prevalence of this condition, Nord believes there are still several things science fundamentally misunderstands about mental health. Mainly the root causes. “We have two camps,” explains Nord. “First, there are the biological causes of depression, such as genetics, or metabolic conditions such as insulin resistance, and [secondly] there are social factors, such as trauma.”
Nord says “it is actively unhelpful to segregate these two types of explanations when, in fact, both social and biological causes all have effects on the brain and the body. Eventually, there’s a kind of common biological pathway for everything, whether that’s trauma or pain”.
What fascinates Nord the most is that neither of these factors is a perfect predictor for the development of depression. “People experience traumatic things, and yet, many of them never go on to develop a mental health problem,” she says. “There are obviously other things going on. There are events happening in the context of your particular brain and your particular brain circuitry. There are certain things that might make you more vulnerable, and more resilient.”
While we are still in the early days of this new approach to mental health treatment, Nord is excited about the future. She believes mindfulness, cognitive behavioural therapy and meditation, are effective ways of improving the brain’s resilience and rewiring thought patterns.
“The brain learns about the world by generating our sense of our body, which is called interoception, and also learns our motivation, and our drive to do things,” says Nord. “Then the brain is supported by chemicals like dopamine, and serotonin. Together, these myriad of things all have downstream effects on these common routes that may affect mental health, and then different treatments can affect these common routes in different ways.”
For this reason, Nord believes treatment for depression must be entirely personalised, but she admits, this dream is still years from becoming a reality. At the moment, antidepressants or even TMS can only target a specific part of the brain. If that isn’t the bit that is damaged in your brain, this treatment won’t help.
“I would hope we would be working on a way to match what’s going on inside someone’s brain with a treatment that we know targets that particular dysfunction,” says Nord. “That might not line up around what we currently call diagnosis.”
In the next few years, Nord hopes we will have a world where depression isn’t cured with a pill but with an arsenal of therapies, customised for the individual’s experience. “I’m not saying next year, but in the coming decade or two,” she says. “That would be my biggest ambition.”
