The troubling link between springtime allergies and suicide

Many allergy sufferers might, when their mucous membranes are burning and their sinuses feel like they’re clogged with Silly Putty, say they want to die. And indeed, some of Postolache’s studies have found links between increases in allergy symptoms, aggression, and mood disturbances. But the connection doesn’t seem to be driven by allergy-induced misery alone. Instead, it appears to be caused by an inflammatory chain reaction that allergens set off in the body.

There are several ways in which a severe reaction to airborne allergens might tip the scales for someone at risk for suicide, but here’s one. When a speck of pollen from the air comes into contact with immune cells in the nose, the cells release cytokines—molecules that cells use to communicate messages to one another. Postolache and others believe cytokines might drift through the nose to enter the brain. There, the cytokines might disrupt the brain’s delicate chemical soup, shifting the balance from feel-good chemicals to toxic ones that may trigger anxiety and impulsive behavior. Besides the nose, cytokines might also influence the brain by traveling through nerves, or by prompting immune cells to mistakenly attack healthy brain cells.

These cytokines, then, may play a role in the angst and impulsiveness that drives people to take their lives. Indeed, Postolache and others found elevated cytokine levels in the brains of suicide victims.