Neurological and mental health conditions like dementia, epilepsy, and depression could become more widespread and severe as global temperatures rise, according to a study released Wednesday by University College London researchers.
The researchers reviewed neuroscience literature to examine how extreme heat and climate change-related disasters affect neurological diseases and mental health disorders. They found that environmental factors not only increase disease prevalence but also raise the risk of hospital admissions, disability, and death.
While the health impacts of climate change have been well documented, particularly for infectious and respiratory diseases, its effects on neurological health are less understood. The body’s temperature regulation appears to play a significant role in worsening conditions triggered by extreme heat.
“The brain needs to be kept within a narrow temperature range to function properly,” explained Sanjay Sisodiya, a professor at UCL Queen Square Institute of Neurology who led the research. “If someone has a neurological disease, their ability to regulate temperature is compromised. Exposure to extreme heat can therefore worsen their condition.”
Sisodiya emphasized the need for more research to understand how higher temperatures specifically affect neurological disorders. This is especially important as extreme weather becomes more frequent, impacting the most vulnerable populations, including the youngest and oldest.
The study reviewed 332 reports on the environmental impacts on 19 neurological conditions, such as Alzheimer’s, dementia, migraine, stroke, multiple sclerosis, and meningitis. The research also included psychiatric disorders like depression, anxiety, and schizophrenia, which often co-occur with neurological diseases. The findings showed that weather affects each condition differently, but generally, higher temperatures are linked to increased prevalence and worsening symptoms.
For example, people with Alzheimer’s and other dementias struggle to make adaptive choices during extreme heat, like seeking help, wearing lighter clothing, and drinking more water. Hotter weather can also lead to more severe or fatal strokes and exacerbate epilepsy, which is worsened by sleep deprivation. High nighttime temperatures, a hallmark of climate change, disrupt sleep patterns and thus impact conditions like epilepsy.
Mental health disorders, hospitalizations, and death risks are strongly associated with increased ambient temperatures. One study included in the review found that US health insurance claims for mental health-related emergency room visits rose on days with extreme heat between 2010 and 2019. Extreme weather events, such as storms and wildfires, can trigger acute anxiety, post-traumatic stress, depression, and suicidal thoughts.
Burcin Ikiz, a neuroscientist studying environmental impacts on the brain, warned that heat-induced brain stress can lead to inflammation and degeneration, affecting cognitive health. She expressed concern that by 2050, neurological disorders could become more common in people in their 40s and 50s, rather than 70s and 80s, due to the cumulative stress from heat, pollution, and microplastics.
Ikiz and Sisodiya called for more research and policy actions to reduce the economic impact of climate change on public health, especially in poorer countries. As the world faces record-breaking summer heat, individuals can also take steps to protect themselves from extreme heat.
“We need to stop burning fossil fuels and reduce emissions,” Sisodiya advised. “But we can also ensure that weather alerts are effective and that people take simple measures like staying out of the sun during peak hours, keeping windows closed, staying cool and hydrated, and having enough medication.”
