In the News: Depression An “Allergic Reaction”?

Earlier this month (January 2015), the Guardian published an article entitled “Is depression a kind of allergic reaction?” In it, author Caroline Williams explained that an increasing number of scientists are suggesting that is how we all should start thinking about it. But what, exactly, does this mean?

In order to understand the basis of this new(ish) theory it is important to understand what, precisely, an allergic reaction is. While most of us associate an allergic reaction with allergies—i.e. sneezing, watery eyes and a runny nose—or hives, an allergic reaction is a “hypersensitive response of the immune system of an allergic individual to [any] substance” (medicinenet.com). In the case of depression, the assumed “substance” is stress while the bodies “response” is inflammatory and, it is believed, this inflammatory response is directly linked to depression.

To be clear: Some scientists are now suggesting depression is a physical ailment—an allergic reaction of sorts—and not a mental illness. That is not to say depression does not affect one’s mental health; it does. It simply implies that depression may be caused by more than imbalanced neurochemicals. George Slavich, a clinical psychologist at the University of California in Los Angeles, explains it best: He states that he doesn’t “even talk about it [depression] as a psychiatric condition any more…[i]t does involve psychology, but it also involves equal parts of biology and physical health.”

This idea is hardly foreign. Individuals struggling with alcoholism or drug addiction are said to be allergic to their substance of “choice,” [I use “choice” for lack of a better word only], and “according to Dr Kramer, the theory connecting infection and psychiatric illness dates back at least to the 1990s.” But what makes this new study groundbreaking is the idea that depression, while affecting your mental and emotional faculties, is a physical illness and—as such—can be treated in a revolutionary new way. Not only has dual drug therapy shown promising results, “the few clinical trials done so far have found that adding anti-inflammatory medicines to antidepressants not only improves symptoms, it also increases the proportion of people who respond to treatment,” preventative treatment options are also being explored—and that is huge.

That said, it is important to note that this theory and these trials are still only in their preliminary stages. Pauline Anderson points out that even though “investigators at the Icahn School of Medicine at Mount Sinai, in New York City, recently linked differences in the peripheral immune system in a mouse model to susceptibility to social stress, findings they correlated with serum cytokine levels in patients with treatment-resistant depression,” actual human trials have been limited. That said, the ever-evolving research “could have huge implications for depression treatment.”

Hooray for science!