Research Shows Link Between Heat, Mental Illness

FireBeing hot is uncomfortable and aggravating, especially when humidity tags along with the heat and hangs heavy in the air. So it’s hardly surprising that a study conducted in a Vietnamese mental hospital during a five-year span showed hospitalizations spiked considerably during heat waves.

The study was published in the form of a thesis by Phan Minh Trang at Umea University in Sweden. Trang looked at admissions at Hanoi Mental Hospital from 2008 to 2012. During the summer, cases of mental disorders spiked 24 percent, he found. As the mercury rose from Hanoi’s mean temperature, hospital admissions rose two percent with each degree. 1

The study was meant to illustrate how the extreme weather conditions in sub-tropical Vietnam have walloped the country with a mental health crisis. Natural disasters in southeast Asia and around the world creates “psychiatric trauma (and) includes severe anxiety reactions such as post-traumatic stress, and longer-term impacts such as generalized anxiety, depression, aggression and complex psychopathology,” Trang writes.

Depression Rises With the Heat

The study was the first to look at an entire hospital population as opposed to at-risk groups such as the elderly, who are especially vulnerable to the heat.

“There were associations between hospital admissions for depression and other mental disorders and seasonality, weather patterns, elevated temperatures and heatwaves,” Trang concluded. “The associations grew stronger with the length of the heatwaves and particularly the elderly appeared more sensitive to seasonality, hot weather and heatwaves.”

Global warming has resulted in natural disasters that have left poor Asian countries devastated. Their citizens have been traumatized by natural disaster, live in sweltering heat and are unable to get the treatment they need, let alone afford air conditioning.

“The poor and more vulnerable population could have improved opportunities and capacities to overcome physical health problems if they had a healthier mental life,” Trang argues.

Alcohol, Drug Use Spike With Heat

But this isn’t just a problem in third world countries. Studies on how heat impacts mental illness have shown similar results in developed nations such as Australia and the United States. Data from the US has shown an association with heat waves and reported mental illness even more so than Australia. At the same time, Vietnam is dealing with some of the same problems the US is in terms of co-occurring conditions affecting the mentally ill, such as heroin abuse and alcoholism.

“Substance abuse consumptions such as alcohol and drugs have been importantly potential risks, causing an increase in mental disorders in Vietnam,” Trang writes. “It may be a genuine concern for health managers in Vietnam to develop programs and solutions aimed at helping young populations so as to avoid substance abuse, because youth are a major human resource for social and economic growth as well as for the flourishment of Vietnam.”

Again, the same could be said for the United States.

Why Air Conditioning is Important

Unfortunately, due to the disabling effects of mental illness, many who live with mental disorders are unable to work. Others are on fixed incomes such as SSI or underemployed.

Most communities do have organizations that provide cooling assistance in the form of electric bill payments for people who meet certain income qualifications. Inexpensive air conditioners in good working condition often can be found at second hand stores or sites like Craigslist.

People with mental illness often have difficulty sleeping. Sweltering temperatures only worsen insomnia issues. It’s also important for people who have animals to remember that if you’re uncomfortable, your pet probably is too. You can always justify spending the money for an air conditioner on your cat if it makes you feel better.

Research has shown that when temperatures go up, so does drug abuse, alcohol abuse, dementia (particularly in the elderly) and anxiety, according to Trang.

But why?

“Results from previous research on associations between physiological-psychological mechanisms and high temperatures as well as brain temperature may provide more evidence to explain the assumption that exposure to heat/heat waves may trigger or exacerbate hospital admissions for mental health disorders among populations at risk in northern region of Vietnam,” he writes. “However, further studies on bio-psychology are needed to confirm the exact mechanism of high temperatures influence on neurotransmitters in treating mental disorders.”


1. Trang, P. (2017). Weather and Extreme Heat in Association to Mental Disorders. The case of Hanoi, Vietnam. Department of Public Health and Clinical Medicine, Epidemiology and Global Health, Umea University, Sweden.

Written by David Heitz


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