The brain is also affected by the climate crisis

Are increasing rates of anxiety, depression, attention deficit hyperactivity disorder (ADHD), post-traumatic stress disorder (PTSD), and Alzheimer's disease linked to high temperatures and other extreme environmental changes? ?

At the end of October 2012, a category 3 storm named Sandy landed in New York (USA) and caused more than 60 billion USD in damage, killing dozens of people and forcing 6,500 patients to evacuate from hospitals and hospitals. nursing home. However, for one neuroscientist, the storm presented an opportunity.

Before the storm's unexpected visit, Ms. Yoko Nomura - who teaches psychology at Queens College, CUNY, as well as psychiatry at the Icahn School of Medicine - assembled a research team of hundreds of mothers. young in New York. Her 2009 investigation, entitled 'Stress during Pregnancy' , aimed to explore the potential risk of prenatal stress on the fetus. Ms. Nomura explores how stressors can cause changes in gene expression, factors known to influence the risk of neurological syndromes in children such as autism and schizophrenia. and ADHD.

However, the storm brought a new question to her research: Does the exposure of mothers to a catastrophic storm have a different impact on their children, compared with children born before or after the storm? after the storm?

More than a decade later, Ms. Nomura has the answer. The conclusions revealed a startling difference: children who were still in the womb during Hurricane Sandy were at extremely high risk of mental illness later in life. For example, girls who were exposed to Sandy, even before birth, had a 20-fold increase in anxiety and a 30-fold increase in depression later in life compared to those who were not exposed. Boys have a 60-fold and 20-fold increased risk of ADHD and conduct disorder, respectively. Children show symptoms of this condition as early as kindergarten.

Flooding in New York, in October 2012, after Hurricane Sandy.

Nomura and her colleagues' research also raises a new question in the climate crisis: that a changing climate not only shapes the environment we live in, but also our brains. Changes caused by fossil fuels – from rising temperatures to extreme weather, as well as rising atmospheric carbon dioxide levels – are altering our brain health, affecting every aspect of our lives. everything from memory and executive function to language, identity formation and even the structure of the brain.

Evidence comes from many different fields. Psychologists and behavioral economists have demonstrated how temperature spikes lead to an increase in everything from domestic violence to hateful comments on the Internet. According to cognitive neuroscientists, elevated temperatures and CO2 levels impair our ability to make decisions, solve problems and learn. Brain-related pathogens, such as ticks and mosquitoes, are expanding their range as the world warms.

Ms Burcin Ikiz, a neuroscientist at psychological health charity Baszucki Group, is particularly interested in the neurodegenerative impact of the climate crisis. Long-term exposure to high temperatures alone can activate countless biochemical pathways linked to neurodegenerative diseases such as Alzheimer's and Parkinson's. Air pollution does the same thing. Therefore, continued burning of fossil fuels, whether through direct or indirect effects, can lead to dementia. Warmer weather also worsens neurodegenerative symptoms.

Other scientists have also noted these factors. 'Signs of Progressive Alzheimer's Disease in Mexico City's Urban Infants, Children, and Young Adults' is part of the title of a recent article authored by Dr. Lilian Calderón-Garciduenas, a toxicologist with The University of Montana (USA) leads the way. Researchers investigated the harmful effects of urban air pollution on biomarkers of neurodegeneration, and found signs of Alzheimer's disease in 202 of the 203 brains they examined. , of people from 11 months to 40 years old. 'Alzheimer's disease, which begins in the brains of young children and affects 99.5% of urban youth, is a serious health crisis,' write Ms Calderón-Garcidueñas and her colleagues.

Smog in Mexico City, Mexico,

Ms Ikiz said the number of people with Alzheimer's disease is expected to triple by 2050 - and that's without taking into account the climate crisis. 'That worries me ,' she said. 'Because in 2050, we will think it's time to try to do something, but by then it will be too late for many people.'

'I think that's why the right thing to do now is to speak up and raise awareness about these issues, as the evidence is emerging and we understand more and more. Because no one wants the damage to go so far that it cannot be repaired ,' she said.

For Ms. Nomura, everything comes back to tension. According to her, under the right conditions, exposure to prenatal stress can have a protective effect. 'It's like a vaccination,' she explained. 'You are exposed artificially to something, and you learn how to handle it better – as long as it's not too toxic' . Stress during pregnancy, in moderation, can help the fetus resist the most harmful effects of stress later in life. 'But there are certain limits,' she said.