Blue Monday

Researchers found suicide risk varies by day of the week and holiday, with certain days correlating to higher risk globally. They used data from 1971 to 2019 and from 740 locations in 26 countries, collected from the Multi-City Multi-Country Collaborative Research Network database to assess short term variations in suicide risk related to the day of the week and national holidays. They found Mondays and New Year’s Day universally correlated with elevated risk, whereas weekends and other public holidays, or the days after them, varied by region. These findings could help both individuals and mental health professionals.

Every year, millions of people the world over suffer the loss of someone due to suicide. In 2019 alone, over 700,000 lives were lost to suicide, according to the World Health Organization, and it ranks as the fourth-biggest killer amongst 15- to 29-year-olds, ahead of even malaria. The factors behind one’s reason for suicide are known to be various, ranging from individual to social factors. But it has also been known for some time that certain time patterns seem to affect suicide rates.

“Our study examines how the risk of suicide varies by day of the week and compares holidays, such as New Year’s Day, Christmas and national holidays, to regular days,” said Associate Professor Yoonhee Kim from the Department of Global Environmental Health at the University of Tokyo. “We found that Mondays and New Year's Day were associated with a higher risk of suicide in most countries, likely due to increased stress corresponding to the start of new cycles. However, the risk on Christmas was generally less pronounced and varied across regions. Other national holidays, aside from New Year's Day and Christmas, were generally linked to a lower risk of suicide.”

Previous studies on this very sensitive topic mainly focused on individual countries, and typically Western cultures. However, Kim and her team felt inspired to perform a study that compares results across global regions with different lifestyles and cultures using a consistent method — their logic being, by applying a consistent approach across multiple countries, it could provide clearer, more directly comparable results. For example, suicide risks were lower on weekends in many countries in North America, Asia and Europe, but increased in South and Central American countries, Finland and South Africa.

“We hypothesize this may be linked to differing weekend drinking cultures, though further studies are needed because other factors, such as religion and work conditions, might also play a role,” said Kim.

Although their findings provide novel scientific evidence from an international perspective, this is an observational study with several limitations. The team hopes further studies, including those more in depth and with broader interdisciplinary clinical aspects will be conducted to validate findings. The study also considers only a selection of locations within a selection of countries; but despite this, the results have important implications for suicide studies and relevant public health policies.

“We must be aware of temporal fluctuations in risk and pay close attention to them. This awareness is crucial not only for vulnerable populations, but also for those working in mental health services,” concluded Kim. “By recognizing periods of higher risk, such as around certain days of the week and holidays, both individuals and mental health professionals can take preventive actions, provide timely support and create a safer environment for the vulnerable.”

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Journal article:

Whanhee Lee, Cinoo Kang, Chaerin Park, Michelle L Bell, Ben Armstrong, Dominic Roye, Masahiro Hashizume, Antonio Gasparrini, Aurelio Tobias, Francesco Sera, Yasushi Honda, Aleš Urban, Jan Kyselý, Carmen Íñiguez, Niilo Ryti, Yuming Guo, Shilu Tong, Micheline de Sousa Zanotti Stagliorio Coelho, Eric Lavigne, Francesca de'Donato, Yue Leon Guo, Joel Schwartz, Alexandra Schneider, Susanne Breitner, Yeonseung Chung, Sooin Kim, Eunhee Ha, Ho Kim, Yoonhee Kim, “Association of holidays and the day of the week with suicide risk: multicountry, two stage, time series study”, The BMJ, http://dx.doi.org/10.1136/bmj-2024-077262

Useful links:
Department of Global Environmental Health
https://sites.google.com/m.u-tokyo.ac.jp/envhealth
Department of Global Health Policy
https://www.ghp.m.u-tokyo.ac.jp/
Graduate School of Medicine
https://www.m.u-tokyo.ac.jp/english/

Research contact:
Associate Professor Yoonhee Kim
Graduate School of Medicine, The University of Tokyo,
7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan
yoonheekim@m.u-tokyo.ac.jp

Press contact:
Mr. Rohan Mehra
Public Relations Group, The University of Tokyo,
7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan
press-releases.adm@gs.mail.u-tokyo.ac.jp

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