What You Can Change _. And What You Can't - Martin E. Seligman [17]
Scientists then could not just look into the brain of one of these dead paretics and see if the syphilitic germ was present. In this era, microscopes were still primitive and tissue stains even worse. When you looked into the brain, what you saw was grayish-white mush. Moreover, the syphilitic organism was unknown—it was just a hypothetical germ; no one had ever seen it. The evidence was mounting, however, that paresis was a disorder of the brain: The pupils of paretics’ eyes didn’t contract when light was flashed on them, and the autopsied brains of dead paretics were shrunken.
It was not only Griesinger who denied that this mental illness is a disease of the body. Unlike today, when we argue that madness is either mental or physical, nineteenth-century common sense held otherwise. Madness was a moral defect, the outward manifestation of a bad character. Strange as this sounds to our ears, this belief was an advance over the common sense of earlier centuries, which had held that madness was possession by the Devil.
Krafft-Ebing changed all this. In one of the most daring experiments in psychiatric history, he showed that general paresis is caused by syphilis. He showed this without once looking at the brain, and he showed this thirty years before anyone was to glimpse Treponema pallidum, the syphilitic spirochete, through a microscope. He knew, as did all streetwise males, that syphilis, like measles or mumps, was a disease you could not catch twice. If you got a sore on your penis once after intercourse with an infected woman, you would be uncomfortable for a few weeks: Urination stung; you might run a fever. After that you seemed to be safe and could then enjoy unlimited pleasure with even the most notorious whores, and never get another sore.
Krafft-Ebing experimented on nine of his patients, all middle-aged men with delusions of grandeur, all of whom vehemently denied ever having had the shameful “French pox” (the Germans called it the French pox; the French called it the Italian pox; the Italians called it the English pox). He scraped material from the penile sores of men who had just contracted syphilis (no armchair science, this) and injected it into these nine paretics.
Not one of the nine developed a sore. The controversy was settled by one monumental experiment. All nine of these men must already have had syphilis, and the syphilitic germ must therefore cause, by some very slow process, general paresis.
Supporting evidence soon cascaded in. Treponema pallidum was discovered, and was found in the brains of paretics. A simple blood test was developed to detect syphilis, and “606,” so named because six hundred and five prior concoctions had failed, was created—it killed Treponema and thus prevented paresis.
So successful was Krafft-Ebing’s work that the most common mental illness of the nineteenth century was eradicated within a generation. (When we look for paretics in Philadelphia—where I teach at the University of Pennsylvania—to instruct present-day medical students, it is very hard to find one.) But Krafft-Ebing, this scientist of courage and genius, accomplished more than just discovering the cause of paresis. With this discovery, he convinced the medical world of something much more global: Mental illness is just an illness of the body. This became the first principle, the rallying cry, and the agenda for the new field of biological psychiatry. A century of research on schizophrenia, depression, Alzheimer’s, and many other problems hypothesized as stemming from some underlying brain disorder followed. Schizophrenia is now seen as caused by too much of a neurotransmitter in the brain; depression by too little of another neurotransmitter; Alzheimer’s by the deterioration of certain nerve centers; overweight by