<strong>The Seasonal Allergy Side Effect That’s Flying Under the Radar</strong>

Reported by Women's Health Magazine.

Sneezing, itchy eyes, a nose that won't quit — seasonal allergies are miserable enough on their own. But there's a symptom most people never connect to their pollen count: a significant shift in mood. According to Women's Health Magazine, allergic rhinitis is associated with a higher incidence of depression than in the general population, and multiple studies show that depression symptoms measurably worsen during peak pollen seasons. One in four Americans deals with seasonal allergies — and a large chunk of them are suffering mentally without knowing why.

The mechanism comes down to inflammation, and it's more far-reaching than most people realize. When your immune system identifies an environmental trigger, it launches an inflammatory response — and that response doesn't stay neatly contained to your sinuses. "There seems to be some sort of inflammatory signal that we're releasing whenever we're in this state of chronic inflammation that feeds back to the brain," says allergist Meagan Shepherd, MD, founder of Shepherd Allergy. A 2026 study in the British Journal of Hospital Medicine backed this up, finding that patients with severe allergies had both worse depression scores and higher inflammatory biomarkers than those with mild symptoms. Research published in Brain, Behavior and Immunity adds another layer: pollen exposure in animal subjects triggered surges in stress hormones and inflammation-linked cytokines in the brain — what Chicago-based allergist and Northwestern clinical professor Priya Bansal, MD, calls your body's internal alarm messengers. When your immune system is overwhelmed, it tells your nervous system. Anxiety, irritability, and low mood can follow.

The Sleep Factor — and What to Actually Do About It

Layer a wrecked night's sleep on top of that inflammatory storm, and the mental health picture gets darker fast. A blocked airway forces mouth breathing, which degrades sleep quality, says immunologist Tania Elliot, MD, of NYU Langone. Research in Nature and Science of Sleep confirms the pattern: the worse your allergy symptoms, the more likely you are to experience insomnia and other sleep disruptions. Poor sleep then amplifies anxiety and depression — a brutal feedback loop that can stretch on for months. Dr. Bansal notes that some patients stop leaving the house entirely during peak season, and that social withdrawal only compounds the psychological toll. "This is not just a few days of a cold," she says. "This is lasting."

The good news: strategic choices make a real difference. Skip diphenhydramine (Benadryl) — it crosses the blood-brain barrier and has been linked to memory issues and cognitive decline — and use caution with montelukast (Singulair), which carries a black-box warning for psychiatric side effects. Second-generation antihistamines like Claritin, Zyrtec, or Allegra are better bets, per Dr. Shepherd. For sleep, try nasal rinses, dilator strips, and an elevated pillow position at night; if your wearable's sleep scores are tanking, that's data worth bringing to your doctor. Outside, aim for afternoons and evenings when pollen counts dip, shower when you return, and let any skin or hair products dry fully before heading out — they act as pollen magnets, says Dr. Elliot.

The bottom line: as Dr. Elliot puts it, "Allergies are not a nuisance — they're a disease," and treating them with that level of seriousness is the first step toward protecting both your physical health and your mental health through every brutal pollen season ahead.

Read the original at Women's Health Magazine.