You may know that Sigmund Freud, the famed founder of psychoanalysis, had a fascination with cocaine and abused it for many years.

But you might not know these three facts that relate to Freud’s longstanding interest in cocaine. Howard Markel, M.D., Ph.D, professor of medical history at the University of Michigan, documents all this and more in his comprehensive, beautifully written book An Anatomy of Addiction: Sigmund Freud, William Halsted and the Miracle Drug Cocaine.

1. Freud was initially attracted to cocaine because he wanted to help a close friend.

One of Freud’s dearest friends, Dr. Ernst von Fleischl-Marxow, was heavily addicted to morphine, and Freud initially believed that cocaine could cure him. A brilliant man and talented doctor, Fleischl-Marxow had an accident while doing research at the age of 25. He “accidentally nicked his right thumb with a scalpel he was applying to a cadaver,” according to Dr. Markel.

This seemingly minor wound turned into a horrible infection and the thumb had to be amputated.

But that wound didn’t heal well either:

Healthy skin had a difficult time filling in the ends of the opening of the incision line, setting up a vicious cycle of skin ulceration, infection and more surgery. To make matters worse, below the gnarled scar tissue, abnormal growths of sensory nerve endings called neuromata formed around the stump of what had formerly been his opposable digit. To say neuromata are painful is an insult to the power of pain…

To quell his constant excruciating pain, Fleischl-Marxow began his descent into a devastating morphine addiction. During this time, cocaine was viewed as a panacea for everything from headaches to indigestion to aches and pains to depression. So Freud started researching cocaine in hopes that it’d also become an amazing antidote to addiction.

In May 1884, Fleischl-Marxow agreed to try cocaine to help him cure his morphine addiction. According to Markel, it’s possible that Fleischl-Marxow was “the first addict in Europe to be treated with this new therapeutic.” And the results were disastrous.

2. Like many doctors, Freud researched cocaine by experimenting on himself.

As Markel writes:

Over the span of several weeks, Sigmund swallowed cocaine dozens of times, in doses ranging from .05 to .10 grams. From these experiences, he was able to compose an accurate précis of the drug’s immediate effects.

(On a side note, he even gifted cocaine to his friends, colleagues, siblings and his fiancée, Martha, “to make her strong and give her cheeks some color.”)

3. Freud wrote a medical analysis on cocaine entitled Über Coca (On Coca) in July 1884.

According to Markel, “the bulk of Über Coca is a well-written, comprehensive review of cocaine in concert with substantive, original scientific data on its physiological effects.” What’s most striking about this work, Markel writes, is that in addition to the science, Freud also “incorporates his own feelings, sensations and experiences.”

This also was Freud’s first major scientific publication. Interestingly and inaccurately, Freud stated that cocaine was an effective remedy for morphine and alcohol abuse. He also glossed over its addictive properties. But this wasn’t his only mistake.

Unfortunately, for Freud, this publication didn’t provide him with the acclaim he’d imagined. The problem? He failed to report, except for a measly postscript, the drug’s anesthetic abilities. His colleague, however, ophthalmologist Carl Koller, did. Through experiments on animals, Koller found that solutions of water and cocaine worked as an effective anesthetic on the eye. He received all the acclaim, and Freud essentially got nada.

After 12 years of “compulsive cocaine abuse,” Markel writes, Freud supposedly stopped using cocaine in the fall of 1896. But:

The precise details of his cocaine use both before and after 1896 may well be among those secrets. Such elusive puzzles recall the historian’s basic dilemma: the absence of evidence does not always signify evidence of absence. In the end, we will likely never know.

What do you know about Freud and his fascination with cocaine or his many years of abuse?

3 Facts You Might Not Know about Freud and His Biggest Addiction