The Shocking Cause of Depression
Before the modern, randomized clinical trial was routine, around 1907, American psychiatrist Henry Cotton began removing decaying teeth from his patients in hopes of curing their mental disorders. Based on observations that patients with high fevers sometimes experience delusions and hallucinations, Cotton had become convinced that psychiatric illness is the result of chronic infection.
If the teeth pulling didn’t work, Cotton moved on to more invasive excisions: tonsils, testicles, ovaries and, in some cases, colons. The rogue doctor’s mortality rate hovered around 45 percent, and many of the ill never had their psychological symptoms alleviated. By 1933, the doctor and the belief that mental disorders were associated with infections were dead.
This belief was revived in 2014, when Turhan Canli, as associate professor of psychology and radiology at Stony Brook University, published a paper in the Biology of Mood and Anxiety Disorders journal asserting that depression and infectious disease were linked.
“The idea that depression is caused simply by changes in serotonin is not panning out. We need to think about other possible causes and treatments for psychiatric disorders,” says Canli.
His assertion that depression results from infection might seem far-fetched, but there are some data to bolster his claim.
Numerous pathogens have been associated with mental illnesses in the past, including Borna disease, Epstein-Barr and certain strains of herpes, including varicella zoster, the virus that causes chickenpox and shingles.
In a study done using the medical records of over three million people, researchers found that any history of hospitalization for infection was associated with a 62 percent increased risk of later developing a mood disorder, including depression and bipolar disorder.
While more studies are needed to make a conclusive decision about precisely what infection’s influence on depression is, the overwhelming amount of research has placed serious doubt in the the minds of many in the psychological community. Henry Cotton, a man who had became a pariah within his own field, might have been onto the truth.
