July 17, 2001 - Cast in bronze, Abraham Lincoln's likeness gazes at tourists over the Washington Mall. The weight of Civil War America forever rests on his narrow shoulders.
Lincoln's steadiness during national turmoil covered his own internal battle with depression. But a new study suggests that for a brief time during his pre-presidential years, colleagues saw him fly into uncharacteristic fits of rage.
Mercury poisoning -- caused by a treatment for depression -- may have triggered these bizarre mood swings, says the study's author Norbert Hirschhorn, MD, a retired public health physician and medical historian. His paper is published in the recent issue of Perspectives in Biology and Medicine.
In his paper, Hirschhorn sifts through numerous historical accounts of the late president's actions during the late 1850s, tying them with new information on medicine Lincoln took during those years -- something called "blue mass" or "blue pill," he tells WebMD. "It was quite commonly prescribed in the 19th century for a number of ailments, everything from pain to liver problems to migraine headaches and melancholia."
Most historians have assumed that Lincoln took the pills daily for constipation, says Hirschhorn. But in his paper, he provides the first chemical analysis of those pills, showing that they contain extremely high levels of mercury -- nearly 40 times higher than current Environmental Protection Agency standards allow. And the mercury was ground into very fine particles, so it was absorbed quickly into the intestine.
"It was a very poisonous dose, very toxic," Hirschhorn tells WebMD.
In following the medical logic of 19th century America, any disorder was treated with an irritant like mercury, which even then was recognized as a poison, he says. "It was called alterative medicine, the theory that a poison would stimulate and flush out the liver and the brain, generally get things moving."
In Lincoln's case, the high daily doses of mercury backfired, "made his melancholia, his depression, worse," he tells WebMD. It took him from someone with mood swings -- who could change from a jovial storyteller to "the very picture of dejection and gloom" -- to a man capable of angry outbursts and "bizarre behavior," says Hirschhorn.
One example: during the 1858 Lincoln-Douglas debate, when Lincoln was said to reach over, pick a man up by the coat collar, and shake him "until his teeth chattered." Lincoln supposedly became so angry "his voice thrilled and his whole frame shook," and only stopped when someone broke his grip.
Other accounts of Lincoln in 1859 describe him becoming "so angry that he looked like Lucifer in an uncontrollable rage" or that his face became "lurid with majestic and terrifying wrath."
"He himself said that [the medicine] was making him cross," Hirschhorn tells WebMD. "Within a few months of becoming president, he stopped taking it. That's the more interesting point, that he realized the effect it was having, stopped taking it, and was able to lead the country during its most critical time in history."
"Some of what we're saying here is uncomfortable for traditional Lincoln historians," says co-author Ian A. Greaves, MD, associate professor and associate dean for research in the School of Public Health at the University of Minnesota in Minneapolis. "But it does help explain this period in Lincoln's history when he was quite erratic, when his behavior was not consistent with what we see in him as president."
While the dosage seems very high, "it was not unusual," Greaves tells WebMD. "In fact, it was recommended that people take these pills until their gums got sore or teeth became loose, which are also signs of mercury poisoning."
Dementia, too, can be the long-term effect of mercury poisoning, he says. "It's a fascinating story that fits into a much broader picture of how mercury was used in the 19th century. It was fortuitous for Lincoln that he was sufficiently self-aware and quit taking [the pills] when the nation needed him to function optimally."