“Woe to you, my princess, when I come. I will kiss you quite red and feed you till you are plump. And if you are forward you shall see who is the stronger, a gentle little girl who doesn’t eat enough or a big wild man who has cocaine in his body,” wrote Sigmund Freud to his future wife, Martha Bernays, on June 2, 1884. On February 2, 1886, toward the end of another letter to Bernays, Freud wrote, “Here I am, making silly confessions to you, my sweet darling, and really without any reason whatever unless it is the cocaine that makes me talk so much.” The two married later that year.

Overworked and suffering from chest and stomach conditions, Emperor Marcus Aurelius took a prescription from his physician, Galen, for opium. According to Galen, the emperor did not like that the drug made him drowsy, so he stopped taking it. Then he found himself unable to sleep, so he started taking it again.