Studies have shown that the climate crisis can trigger anxiety and depression. But the stress caused by the occurrence of extreme climate events, which are constantly increasing, could impact the mental health of individuals in other ways, and, in particular, be the cause of neurological disorders.
This is what has emerged from research by Yoko Nomura, professor of psychology and psychiatry at Queens College and the Icahn School of Medicine at Mount Sinai, over the past 15 years.
Working on the topic of prenatal stress since 2009, the New York-based researcher decided to take her work in a new direction when one of the most devastating hurricanes in history hit the eastern seaboard of the United States. It was October 2012, and this climate disaster is now known as “Superstorm Sandy”.
Of those in the female cohort studied by Nomura, 690 were pregnant. The researcher included the occurrence of this hurricane in the criteria of stressful events (on the same level as a divorce or job loss).
The aim was to understand how environmental stressors can alter gene expression and influence the risk of specific neurobehavioral disorders in children such as autism, schizophrenia, or attention deficit disorder with or without hyperactivity (ADHD).
Nomura, therefore, investigated whether the prenatal stress of living through an extreme climatic event could have consequences for the brains of unborn children, compared to those conceived before or after Superstorm Sandy.
The results of her study suggested that children exposed in utero to the hurricane are now at greater risk of developing psychiatric disorders. In particular, girls who were exposed to Sandy prenatally experienced a 20-fold increase in anxiety and a 30-fold increase in depression later in life, compared with those who were not exposed.
The boys had 60- and 20-fold increased risks of ADHD and conduct disorder, according to the study, originally published in 2017 and updated in 2022, with annual follow-up on children conceived during Superstorm Sandy aged three on average.
Nevertheless, “more attention is needed to understand specific parent, child, and environmental factors which account for this increased risk and to develop mitigation strategies”, Nomura wrote.
This isn’t the only research that suggests a link between extreme climate events and mental health consequences. Previous studies have shown that forest fires were associated with a 6.3% increase in emergency room visits for severe anxiety disorders, particularly among women and the elderly.
Separate findings have also indicated that the inhalation of smoke fumes could result in damage to brain health.