Monday morning blues are to blame for a majority of suicides among middle-aged and older Japanese males, a study shows.

While it comes as no surprise that men with suicidal tendencies tend to take their lives on a Monday, compared with other days of the week, researchers found for the first time that older male company employees are more likely to commit suicide early on a Monday morning, or during the morning commute.

The study was done by Michiko Ueda, an associate professor of public health at Tokyo's Waseda University, and her colleagues at other institutions.

“Offering more help on a Monday morning and keeping a close watch over commuters at train stations during the morning commute could be effective in curbing suicides,” Ueda said.

Some hotlines set up to prevent suicides take calls only between the evening and late at night.

The team analyzed 900,000 suicides to ascertain which day and time zone was most common. The statistics covered the past 41 years through 2014.

The researchers discovered that suicides among male workers aged between 40 and 65 occurred most often between 4 a.m. and 8 a.m. on Mondays.

That was roughly 2.5 times higher than the figure between 8 p.m. and midnight on a Saturday, the time when suicide by men in that age group was least common.

The trend of middle-aged or older male employees committing suicide on Monday mornings emerged in 1995 and later after the asset-inflated economy collapsed in the early 1990s, according to researchers.

The study also showed that the percentage of their suicides in the morning rose when unemployment rates increased.

Records show that 21,321 people killed themselves in Japan in 2017.