More frequent spells of intense humidity caused by the climate crisis are more likely than heatwaves to be linked to increased rates of suicide, according to new research.
The study found that women and young people were particularly affected by levels of humidity, the intensity and frequency of which are increasing because of global heating.
Based on data from 60 countries between 1979 and 2016, the study, by researchers at the universities of the UN, Sussex and Geneva, as well as University College London, found that periods of intense humidity were more strongly linked to suicide than high temperatures.
Dr Sonja Ayeb-Karlsson, who co-authored the research, said humidity interfered with the body’s ability to regulate its temperature and that this increased discomfort could exacerbate conditions for people already struggling with mental illnesses.
“If you talk about mental health there are quite a lot of links – there’s anxiety, it’s hard to sleep, it becomes unbearable,” she said. “Sleep deprivation is a massive thing … It’s difficult to sleep when it’s hot and even more when it’s humid.”
Those already struggling with their mental health could be more affected by increased humidity than other people because antidepressants can interfere with the body’s ability to regulate its temperature, she added.
According to the study, 40 countries had a particularly strong link between suicide and humidity. The list included hot countries such as Thailand and Guyana, but also European countries that were less used to higher heat and humidity, including Sweden, Belgium and Luxemburg.
“It’s the shock of going from colder temperatures to extreme temperatures that is dangerous to mental health,” said Ayeb-Karlsson.
Ayeb-Karlsson said this was the first time such a study had been carried out on a global scale rather than on a country basis. She said it showed the impact that the climate crisis had on mental health and the threat posed to the World Health Organization’s aim to reduce suicide rates by a third by 2030. There are currently more than 700,000 suicides every year.
“The study found interesting trends related to the increased suicide rates among, particularly, women and youth in relation to humidity. Women and children are known to be suffering disproportionately from the impacts of climate change and extreme weather events due to social structures and power relations. We need to look further into these relations and the contextual reasons behind this in diverse geographical areas and social groups,” she said.
In the UK and Ireland, Samaritans can be contacted on 116 123 or email jo@samaritans.org or jo@samaritans.ie. The charity Mind is available on 0300 123 3393 and ChildLine on 0800 1111. In the US, Mental Health America is available on 800-273-8255. In the US, the National Suicide Prevention Lifeline is at 800-273-8255 or chat for support. You can also text HOME to 741741 to connect with a crisis text line counselor. Other international helplines can be found at www.befrienders.org