Was Abraham Lincoln's legendary temperament actually a side effect of mercury poisoning?

Cultures · Published 10 October 2026 Swipe more like this →

In short: Abraham Lincoln is remembered for his melancholy and occasional outbursts of rage. While historians have long debated his mental health, some suggest his erratic behavior and physical tremors were not psychological, but the result of mercury poisoning from blue mass pills he took to treat his persistent constipation and depression.

Abraham Lincoln’s health has been the subject of intense scrutiny, ranging from his well-documented struggles with depression to theories about rare genetic disorders. Throughout his life, Lincoln suffered from periods of profound melancholy, which contemporaries and modern professionals alike have linked to significant personal traumas, including the deaths of his mother, sister, and two sons. To manage these moods and chronic constipation, he frequently took blue mass pills—a common 19th-century remedy containing elemental mercury. Researchers have noted that when Lincoln was taking these pills, he exhibited symptoms consistent with mercury poisoning, such as insomnia, memory loss, and sudden outbursts of rage. After he stopped taking the medication in August 1861, his temper reportedly became much more controlled.

Beyond his mental state, Lincoln’s physical appearance has fueled decades of medical speculation. His six-foot-four stature, thin frame, and facial asymmetry led some historians to propose he suffered from Marfan syndrome or multiple endocrine neoplasia type 2B (MEN2B). However, these theories face significant challenges. Marfan syndrome is often questioned due to Lincoln’s unremarkable cardiovascular history and normal vision, while the MEN2B hypothesis is contradicted by his longevity; the condition typically leads to death by age 21, yet Lincoln lived until his assassination at 56. Recent research and genetic testing attempts have failed to provide conclusive evidence for these genetic diagnoses.

Lincoln’s medical history also included several acute illnesses and injuries. He contracted malaria in 1830 and 1835, and he suffered from smallpox during an epidemic in Washington, D.C., in 1863. While he survived these, his valet, William H. Johnson, died from the smallpox he contracted while caring for the President. Other physical traumas, such as being kicked in the head by a horse at age nine and suffering frostbite in 1830–1831, marked his early life. Despite these challenges, historians generally agree his health was fairly good for his era until his assassination in 1865.

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