Anyone who has taken high school science classes knows that human beings are made of chemicals and that the study of those chemicals and the structures in which they are configured is called biology. Everything that happens in the brain has chemical manifestations and sources. If you close your eyes and think hard about polar bears, that has a chemical effect on your brain. If you stick to a policy of opposing tax breaks for capital gains, that has a chemical effect on your brain. When you remember some episode from your past, you do so through the complex chemistry of memory. Childhood trauma and subsequent difficulty can alter brain chemistry. Thousands of chemical reactions are involved in deciding to read this book, picking it up with your hands, looking at the shapes of the letters on the page, extracting meaning from those shapes, and having intellectual and emotional responses to what they convey. If time lets you cycle out of a depression and feel better, the chemical changes are no less particular and complex than the ones that are brought about by taking antidepressants. The external determines the internal as much as the internal invents the external. What is so unattractive is the idea that in addition to all other lines being blurred, the boundaries of what makes us ourselves are blurry. There is no essential self that lies pure as a vein of gold under the chaos of experience and chemistry. Anything can be changed, and we must understand the human organism as a sequence of selves that succumb to or choose one another. And yet the language of science, used in training doctors and, increasingly, in nonacademic writing and conversation, is strangely perverse.
The cumulative results of the brain's chemical effects are not well understood. In the 1989 edition of the standard Comprehensive Textbook of Psychiatry, for example, one finds this helpful formula: a depression score is equivalent to the level of 3-methoxy-4-hydroxyphenylglycol (a compound found in the urine of all people and not apparently affected by depression); minus the level of 3-methoxy-4-hydroxymandelic acid; plus the level of norepinephrine; minus the level of normetanephrine plus the level of metanepherine, the sum of those divided by the level of 3-methoxy-4-hydroxymandelic acid; plus an unspecified conversion variable; or, as CTP puts it: "D-type score = C1 (MHPG) - C2 (VMA) + C3 (NE) - C4 (NMN + MN)/VMA + C0." The score should come out between one for unipolar and zero for bipolar patients, so if you come up with something else -- you're doing it wrong. How much insight can such formulae offer? How can they possibly apply to something as nebulous as mood? To what extent specific experience has conduced to a particular depression is hard to determine; nor can we explain through what chemistry a person comes to respond to external circumstance with depression; nor can we work out what makes someone essentially depressive.
Although depression is described by the popular press and the pharmaceutical industry as though it were a single-effect illness such as diabetes, it is not. Indeed, it is strikingly dissimilar to diabetes. Diabetics produce insufficient insulin, and diabetes is treated by increasing and stabilizing insulin in the bloodstream. Depression is not the consequence of a reduced level of anything we can now measure. Raising levels of serotonin in the brain triggers a process that eventually helps many depressed people to feel better, but that is not because they have abnormally low levels of serotonin. Furthermore, serotonin does not have immediate salutary effects. You could pump a gallon of serotonin into the brain of a depressed person and it would not in the instant make him feel one iota better, though a long-term sustained raise in serotonin level has some effects that ameliorate depressive symptoms. "I'm depressed but it's just chemical" is a sentence equivalent to "I'm murderous but it's just chemical" or "I'm intelligent but it's just chemical." Everything about a person is just chemical if one wants to think in those terms. "You can say it's 'just chemistry,' " says Maggie Robbins, who suffers from manic-depressive illness. "I say there's nothing 'just' about chemistry." The sun shines brightly and that's just chemical too, and it's chemical that rocks are hard, and that the sea is salt, and that certain springtime afternoons carry in their gentle breezes a quality of nostalgia that stirs the heart to longings and imaginings kept dormant by the snows of a long winter. "This serotonin thing," says David McDowell of Columbia University, "is part of modern neuromythology." It's a potent set of stories.
A Man Called Intrepid author dies aged 89(Dec 03 2013) William Stevenson, a journalist and author who drew on his close ties with intelligence sources to write two best-selling books in the 1970s, A Man Called...