Hot weather is linked to an increase in suicidal thoughts and behavior in young people, researchers said. The new study adds to existing evidence that rising temperatures also affect the mental health of adult men and women.

There are several well-known risk factors associated with youth suicidality and suicide: a recent or serious loss, such as the death of a parent; stressful life events such as bullying; psychiatric illness, especially a mood disorder such as depression; trauma; and problems with substance abuse.

But new research conducted by the University of New South Wales (UNSW) Sydney has added another risk factor. A link has been found between high temperatures and an increase in suicidal thoughts and behavior in young people.

Researchers examined 55,000 emergency department (ED) suicidal presentations made by people aged 12 to 24 in the state of New South Wales during the Australian warm months (November to March) between 2012 and 2019.

When they compared this data to daily mean temperature (DMT) and heat waves, they found that the odds of teens going to the emergency room for suicidal tendencies were significantly higher on hot days. The relationship was linear: For every 1 °C (1.8 °F) increase in DMT, youth emergency room visits for suicidal ideation or behavior increased by 1.3%.

“The impact of the first day when the temperature is higher than normal is just as bad as each subsequent day, with the impact starting at a more moderate temperature than expected,” said Dr Cybele Dey, a psychiatrist and lecturer at UNSW Sydney. leader of the study and corresponding author.

For example, on days when the 24-hour average temperature was 21.9 °C (71.4 °F), the average DMT for the study period, there were an average of 45.7 youth suicidality incidents statewide. Presentations at this temperature were 4.7% higher than they would normally be at the cooler DMT of 18.3 °C (64.9 °F), the state’s spring average.

When DMT rose to 25.2 °C (77.4 °F), the onset of a heat wave, presentations were approximately 9% higher than in spring DMT. Presentations were approximately 15% higher when DMT reached the ‘overheat’ temperature of 30 °C (86 °F).

“There was an increase in presentations on the first moderately warm day, which tells us that this is a biological effect rather than a flow-on effect resulting from factors such as poor sleep,” Dey said. “The heat itself seems to do something to increase people’s distress, and this is supported by other literature. We know that calls to mental health crisis lines increase with temperature, and there are overseas studies that show a link between heat exposure and suicidality, as well as a link between increased fever and death by suicide.

Inside August 2024Curtin University-led research found that over an almost 20-year period, around 0.5% of suicide deaths in Australia (264 people) were associated with unusually high temperatures caused by climate change. Suicides associated with temperature abnormalities were statistically significant among men aged 55 and over. Seasonality was an important factor; There were more deaths in the spring (September to the end of November) and summer (December to the end of February).

A few months ago, AprilResearch led by the University of Sydney found a link between high fevers and mental health conditions at a Sydney hospital, particularly for women, where the risk increased significantly at temperatures of 29.2 °C (84.6 °F) or above.

Researchers in the current study said socioeconomic disadvantage associated with lower quality housing and air conditioning ownership and use is a relevant consideration, as is more limited access to green spaces and waterways.

Psychiatrist and senior lecturer at the UNSW School of Clinical Medicine and a collaborator on the study, Dr. “Independent access to green space, cooling off with sea breezes at night and the quality of your housing are important factors that determine how people cope with the heat,” said Iain Perkes. – responsible author. “We will need to do more research on these possible mediating factors, but that shouldn’t stop us from making sensible changes to reduce exposure to higher temperatures that we know work more broadly.”

Improving the quality of housing and giving young people access to cool environments at home and at school would help better protect them from the mental health effects of high temperatures, they said.

“Public health messages about heat are often limited to heat waves and focus on the very young and elderly,” Dey said. “But we need to do more to warn and protect the entire population about the impact it can have on both their physical and mental health.”

Environmental Doctors Australia A group of medical doctors (DEA) who are calling for climate action to reduce health harms have called for an urgent phase-out of fossil fuels, based on the study’s findings.

“Our research shows that the mental health of young Australians is damaged by the heat, and we know that climate pollution is contributing to increased weather extremes, including heat,” said James Scott, professor of child and adolescent psychiatry and DEA spokesman. “We need an urgent and rapid transition from fossil fuels to clean energy to reduce heat-related mental health harms and emergency room visits for children and young people,” study co-author said.

More research is needed on the link between young people’s mental health and fever to confirm whether high temperatures cause the increase or are coincidental with it.

“It’s pretty surprising,” Perkes said. “Although we have not been able to establish causality here, the type of pattern…suggests a cause-and-effect response.”

The study was published in the journal Australian and New Zealand Journal of Psychiatry.

Sources: UNSW Sydney, DEA