Wayne State research reveals link between seasonal allergies and suicide risk

DETROIT - Wayne State University researchers have uncovered a striking new connection between seasonal allergies and mental health: spikes in pollen can increase the risk of suicide. The groundbreaking study, published in the Journal of Health Economics, suggests that even small health shocks - such as allergy flare-ups - can have profound consequences on mental well-being, particularly among people already vulnerable to mental health challenges.

The research team, led by Wayne State Associate Professor of Economics Shooshan Danagoulian, examined more than a decade of daily data from 34 U.S. metropolitan areas between 2006 and 2018. By combining pollen counts, suicide data and online search behavior, the team - including co-authors Owen Fleming, a Wayne State Ph.D. student in economics, and Joelle Abramowitz at the University of Michigan - demonstrated a clear and consistent relationship: as pollen levels rise, so do the number of suicides

"At the highest pollen levels, we observed up to a 7.4% increase in suicides," Danagoulian said. "What's particularly concerning is that individuals with a known mental health condition or treatment history had an even greater increase - 8.6% - on high-pollen days."

While itchy eyes and runny noses may seem like minor inconveniences, allergies can disrupt sleep, impair concentration and lower mood - well-known risk factors for suicide. To further validate their findings, the team analyzed Google Trends data and found a spike in searches related to both allergy symptoms and depressive thoughts during high-pollen days.

This evidence strengthens the case that allergies don't just affect physical health; they can tip the scales for those already struggling with mental well-being.

Climate change impact The study also warns of an escalating threat: climate change is intensifying and lengthening pollen seasons. Plants are blooming earlier and releasing more pollen into the air, meaning that what is already a seasonal burden may soon become a year-round risk. The researchers estimate that by the end of the century, the effect of pollen on suicides could more than double.

"This is an overlooked cost of climate change," Danagoulian explained. "We often focus on environmental damages, but here we see clear evidence that climate change may also worsen mental health outcomes in ways that haven't been fully considered."

Simple interventions

One of the most powerful takeaways from the study is that the risks identified are preventable. Unlike many mental health risk factors, seasonal allergies are highly treatable with safe, inexpensive and widely available options such as antihistamines, nasal sprays and allergy testing.

"Small, accessible health interventions could have lifesaving impacts," Danagoulian noted. "If managing allergies helps reduce suicide risk even slightly, it represents a meaningful step in addressing one of the most pressing public health crises of our time."

This research underscores Wayne State's leadership in addressing complex, real-world health challenges that affect both Detroiters and communities nationwide. By identifying a surprising yet actionable link between environmental health and mental health, Wayne State researchers are opening new pathways for prevention, treatment and policy.

The findings not only advance academic understanding but also offer concrete guidance for health care providers, policymakers and families.

Looking ahead

As suicide rates in the United States continue to climb - rising 37% from 2000 to 2018 - studies like this highlight the importance of examining not just long-term structural factors, but also short-term, everyday triggers that can tip someone into crisis. By shining a light on seasonal allergies as one such factor, Wayne State researchers have brought attention to the need to better understand the downstream effects of seasonal allergies.

"Our goal is to show that mental health is sensitive to seemingly innocuous health shocks," Danagoulian said. "Funded by a grant from the American Foundation for Suicide Prevention, our next step is to examine the relationship between pollen and mental health in rural communities experiencing challenges in mental health care and pharmacy access."