Most people commit suicide on a Monday, says study

In most countries, Mondays have the highest risk of suicide during weekdays, while New Year’s and the consecutive days are associated with a risk increase, according to a study. On the other hand, suicide cases on weekends and Christmas vary by country and territory.

"The results of this study can help to better understand the short-term variations in suicide risks and define suicide prevention action plans and awareness campaigns,” the investigators said.

This multi-country study employed a two-stage, time series design and obtained data from 740 locations in 26 countries and territories, with overlapping periods between 1971 and 2019, using the Multi-city Multi-country Collaborative Research Network database. A total of 1,701,286 suicide cases were registered and included in the analysis.

Suicide risk peaked on Mondays during weekdays (Monday-Friday) across all countries, with relative risks (RRs) ranging from 1.02 (95 percent confidence interval [CI], 0.95–1.10) in Costa Rica to 1.17 (95 percent CI, 1.09–1.25) in Chile. Such risk was lowest on Saturdays or Sundays in many countries in Asia, Europe, and North America but increased in South and Central American countries, Finland, and South America.

There was also a substantial increase in suicide risk on New Year’s Day in many countries, with RRs ranging from 0.93 (95 percent CI, 0.75–1.14) in Japan to 1.93 (95 percent CI, 1.31–2.85) in Chile, while that on Christmas day was low. [BMJ 2024;387:e077262]

Additionally, suicide risk correlated with a weak decrease on other national holidays, except for Central and South American countries, which had a generally higher risk 1 or 2 days after the holidays.

"Our findings contribute to the implications for national and global suicide prevention strategies in both industrialized and less-industrialized countries considering public health resource allocation and mobilization,” the investigators said.

Blue Monday

The findings on Mondays and New Year’s Day were consistent with previous studies and could be driven by the “broken-promise effect theory,” which suggests that suicides are usually postponed until after a holiday. [Affect Disord 2016;197:175-181; J Emerg Med 2014;46:776-781; Psychiatry Res 2008;157:139-146]

Another possible explanation was the “Blue Monday,” which indicates that the beginning of a week makes people distressed by work pressure. Moreover, the increased consumption of alcohol before and on New Year’s Day and weekends was found to heighten the risk of suicide. [J Affect Disord 2004;83:1-9; Ideggyogyaszati Szemle 2022;75:99-104]

“Regardless, we found different patterns of suicide risk by day of the week in several countries, where the risk peaked during the weekends, but not necessarily on Monday,” the investigators said.

Other studies reported similar results. For instance, studies in Colombia and Brazil noted higher suicide risks on weekends and holidays in relation to alcohol intake. This was also true in Finland, which could be linked to their drinking culture. [Br J Psychiatry 2012;34:34-37; Braz J Psychiatry 2016;38:222-230; Arch Suicide Res 2023;27:1-20; J Affect Disord 2004;78:11-9]

"Higher rates of alcohol consumption on the weekends in comparison to weekdays might be common across various countries; therefore, additional underlying factors, such as religion and working conditions might be at play,” the investigators said. [Prev Sci 2016;17:872-881]

“Our results support the necessity of in-depth studies to investigate these factors,” they added.