Why is there a higher suicide rate in the spring?

The suicide rate goes up in spring and summer—not winter as many believe—and studies suggest a link between immune-system inflammation from pollen and seasonal depression.

Thanks to heightened public awareness of seasonal affective disorder, conventional wisdom now says that most suicides occur during the cold, dark months of winter, but that’s wrong — it’s actually the warmer months. It’s a serious problem, too: In the U.S. in 2015, for example, the CDC reports there were 44,193 suicides, or 13.7 for every thousand people. It’s been suggested that seasonal depression might have to to do with springtime taxes, but something more biological might be the cause. It could be pollen.


It would be understandable that paying one’s taxes could drive a person over the edge. According to statistics from 2017, the average American household is $137,063 in debt, a scary number made even more so with the realization that the average family income is only $59,039. This tax bill is low compared to other developed nations, by the way: A U.S. couple with two kids pays about 20.1% of their gross income, while in Belgium it’s nearly double that, at 37.8%. It needs to be said, however, that countries with higher taxes tend to have government-provided universal healthcare and other services that reduce citizens’ year-round expenses. And anyway, suicides actually peak beyond tax season, in July.

Inflammation may be the key

There’s a fair amount of research that links inflammation to depression. A 2016 study found that “Major depressive disorder may be due to psychoneuroimmunological dysfunction, as studies have documented increased levels of a variety of inflammatory mediators in depressed subjects.” This was a large study of 14,275 people, and the scientists found that 46% of those self-reporting as depressed had an increased amount of C-reactive protein (CRP), a marker for inflammation. Another study linked inflammatory cytokines to depression. As Marlynn Wei writing for Psychology Today puts it, “The theory that depression may be viewed as a psychoneuroimmunological disorder can also help explain why efforts to reduce chronic inflammation in the body also improves and helps prevent depression.”

(U.S. Marine Corps photo by Cpl. Russel Midori)

It’s a pollen time of year

One factor that’s certainly, um, in the air in spring and summers is tree pollen. Olga Khazan in The Atlantic reports on a study done in Denmark that found suicides going up by 13.2% when pollen was present. Japanese researchers also found that female suicides spiked in the presence of pollen. Another study considers pollen as a suicide trigger due to its production of “seasonally increased cytokine production in upper airways.” It also notes that experiments with rodents show the administering of tree pollen caused “behavioral alterations consisting of increased anxiety and disturbed social interaction.” Maybe the most convincing evidence cited in the study is this: “Finally, victims of suicide have an increased level of gene expression of allergy-related cytokines in the orbitofrontal cortex, a region of the brain manifesting histopathological abnormalities in suicide victims.”

Pollen: It’s not just for sniffles

More study is required to fully solidify the link between pollen, mood disorders, and suicide, but it makes sense: Pollen leads to inflammation which leads to depression. It’s difficult to imagine exactly what could be done to reduce exposure to pollen — other than staying inside — without disturbing its role in the germination of plants and crops. Inflammation, though, is something that can be treated, and confirming its role as a suicide trigger could mean a whole new way of helping.

--

LinkedIn meets Tinder in this mindful networking app

Swipe right to make the connections that could change your career.

Getty Images
Sponsored
Swipe right. Match. Meet over coffee or set up a call.

No, we aren't talking about Tinder. Introducing Shapr, a free app that helps people with synergistic professional goals and skill sets easily meet and collaborate.

Keep reading Show less

Think you’re bad at math? You may suffer from ‘math trauma’

Even some teachers suffer from anxiety about math.

Image credit: Getty Images
Mind & Brain

I teach people how to teach math, and I've been working in this field for 30 years. Across those decades, I've met many people who suffer from varying degrees of math trauma – a form of debilitating mental shutdown when it comes to doing mathematics.

Keep reading Show less

A world map of Virgin Mary apparitions

She met mere mortals with and without the Vatican's approval.

Strange Maps
  • For centuries, the Virgin Mary has appeared to the faithful, requesting devotion and promising comfort.
  • These maps show the geography of Marian apparitions – the handful approved by the Vatican, and many others.
  • Historically, Europe is where most apparitions have been reported, but the U.S. is pretty fertile ground too.
Keep reading Show less

How KGB founder Iron Felix justified terror and mass executions

The legacy of Felix Dzerzhinsky, who led Soviet secret police in the "Red Terror," still confounds Russia.

Getty Images
Politics & Current Affairs
  • Felix Dzerzhinsky led the Cheka, Soviet Union's first secret police.
  • The Cheka was infamous for executing thousands during the Red Terror of 1918.
  • The Cheka later became the KGB, the spy organization where Russia's President Putin served for years.
Keep reading Show less