Mechanisms Versus Diagnoses

Abstract

Science is a branch of scholarship: it provides explanations for material phenomena in terms of matter and energy. Medicine by contrast is a trade: it applies scientific knowledge but also requires nonscientific skills such as empathy. Neurochemistry is the science that deals with the molecules that make up nervous systems and with their interactions. Neurology and psychiatry are the trades of those who try to help people with diseases of the nervous system to heal. Scientists including neurochemists have the luxury of taking the time needed to probe deeply into the phenomena they study. Neurologists and psychiatrists more often face sharp constraints on how long they can take to try to help the sick human beings for whom they care. Examples used to illustrate this distinction include psychoses and demyelinating diseases. The existence of a large and often impressive body of scholarship in neurology and psychiatry can foster the illusion that these are scholarly rather than fundamentally practical activities. For convenience, modern physicians conceptualize the phenomena they see as discrete “diseases.” Sometimes their concepts turn out to be scientifically valid. Often, sadly, they do not. The current chapter deals with neurochemical mechanisms rather than listing abnormalities in molecules in clinically defined “diseases.” Neurochemical mechanisms in sick people are real-world entities that can be discovered by observation and whenever possible by experimentation. “Diseases” are abstractions constructed by physicians and others to help figure out what is wrong with patients and how to try to help. This chapter is on the chemistry of nervous systems of people whose actions are unusual enough to draw medical attention to them. It does not deal with such nonmaterial concepts as “free will” or “the soul,” nor with the relationship of mind to brain. This limitation is intentional and potentially powerful. A neurologist or psychiatrist armed with the array of chemicals that constitute the modern pharmacopeia can do much more than even the most sympathetic and understanding physician or other counselor who is limited to “talk therapy.” Sigmund Freud and his fellow alienists in Vienna at the turn of the last century yearned to have such medicines available. In general, the Viennese-trained psychiatrists who fled to the United States were perfectly willing to use psychotropic medications, although they made sure to talk extensively to their patients as well. Even the psychoanalysts in that group held to the slogan, “There is also a brain.” Despite the disputes among “schools of psychoanalysis” that went on with talmudic intensity, the able among those practitioners never forgot that their goal was to aid the troubled individuals who came to them for help.