If you suffer from seasonal allergies, you already know the pollen-rich blooms of spring and fall can usher in several weeks of watery-eyed, congested misery. Researchers at the University of Maryland School of Medicine have gone further and shown that seasonal allergies can deepen the misery of existing depression.
During the height of allergy season, the scientists monitored symptoms and took blood samples from people who had been previously diagnosed with depression. Their depression tended to worsen when they had observable allergy symptoms. The subjects also suffered more depressive symptoms when they didn't have allergy symptoms, but their blood still showed signs of an immune reaction to pollen.
The findings indicate that allergies can make depression worse in those who suffer from both conditions. It's the first time that's been shown. While more research is needed to understand how allergies may make depression worse, the findings also indicate that treating a depressed person's allergies may help improve their mood, even if they aren't actually experiencing symptoms of an allergic reaction.
Scientists have long suspected a link between depression and allergies, but they still don't know exactly how the former might cause the latter. A 2008 story in USA Today noted some theories that used inflammation and sleep loss to draw the missing links.
In the meantime, consider the possibility that your favorite antihistamine could function as an antidepressant, too.
Photo by Cordey