Mental Illness and the Mind-Body Problem

The stuff of love, I’m hearing rumors,May comprise a hundred humors,Numerosity enough To call reductionism’s bluff And yet permit analysis,When things go wrong, of what’s amiss.

“There is no mental illness,” writes Thomas Szasz in a recent article in Reason, repeating for the nth time his mantra of the past four decades. “Bodily diseases-pneumonia, cancer, and so on–are real,” he told the interviewer, “but mental diseases are metaphoric diseases, in the sense of a ‘sick’ joke. They are problems, but they are not medical problems in that they do not involve somatic, organic etiologies and are not amenable to a somatic, organic resolution. They are essentially conflicts within oneself and conflicts between oneself and other people.”²

Dr. Szasz seemed unimpressed by recent MRI and PET data indicating physical brain disorder in schizophrenic and manic-depressive states, apparently because the tests lack sufficient specificity. However, if schizophrenia were eventually proven to arise from some kind of neurological defect, Szasz admitted that this would not change his view of mental illness. Part of his reason appears to be that having a physical disease (which category would then include schizophrenia) should not absolve one of responsibility for one’s actions.

The ruminations of an aging iconoclast find ready acceptance in libertarian journals, probably because he tacitly assumes the existence of free will, and also because he concludes that governmental coercion should not be used against the “mentally ill” by reason of their non-existent illness. However, some forms of intimidation seem acceptable in the Szaszian world view, such as capital punishment for a delusional schizophrenic who has, quite irresponsibly, committed murder.

Szasz’s unique perspective is useful to orthomolecular physicians for the same reason that pathology benefits medical students and mutations aid geneticists: the bizarre, warped and unexpected define the boundaries of that which is normal or at least preferable. Szasz’s views invite us to reconsider the definitions of “mental” and “illness”, and to recast the ancient mind-body problem in modern terms. They also touch upon the issue of biological determinism vs. free will, but I shall defer the latter discussion to a future essay.

One can scarcely doubt that mental and physical phenomena exist in the world, and that these categories exist largely separately from one another. Physical things include water, electricity, the human body, pencils, mass; mental things include pain, love, belief, rage, intentionality and kindness. How are the two categories related, and how do mental things fit into our general world view? That is the nub of the mind-body problem, which Schopenhauer rightly referred to as “the world knot.”

The philosopher Michael Huemer has summarized the various philosophic approaches to this classic issue.³ First there is parallelism, the view that both types of phenomena exist but are utterly independent of one another. Then there is Cartesian dualism: body and soul co-exist and interact with one another causally, though it is not known how. Property dualism holds that mental properties represent a distinct aspect of certain physical objects (for instance, people) although not requiring a distinct entity (soul) to harbor the mental ones. Epiphenomenalism says that physical events cause mental events and physical events cause behavior, but mental events themselves don’t cause anything.

(The first and last of these seem quite counterintuitive to a writer whose mental events are presently causing symbols to materialize on a computer screen.)

To round out the list there are two extreme views–either physical phenomena do not exist at all, or there are no mental phenomena–and one moderate view, the mind-brain identity theory. In the latter, mental phenomena are considered to be a subset of physical phenomena; namely, they are states of the central nervous systems of animals. “Pain,” for example, refers to a certain kind of mental state, and “depression” to another.

Szasz would appear to be approaching the problem from one of the dualistic viewpoints or perhaps parallelism. (One would need to read a lot more Szasz than one has time or appetite for, in order to be sure about that.) He cannot, in any case, be a proponent of the mind-brain identity theory that underlies, at least tacitly, biological psychiatry, and more particularly orthomolecular psychiatry.

Under the mind-brain identity theory, mental illness not only exists, it is in principle definable with considerable precision in physical terms. Mental illness is a form of behavior with which we take issue (a nod to Szasz, here), intimately associated with aberrant central nervous system function, conveniently defined (for now, at least) by biochemical parameters lying outside species norms.

It may come as a surprise to the readers of Reason, though not to those of this Journal, that mental illness has been describable in this manner for many years, longer in fact than the duration of Dr. Szasz’s doubting-Thomas status. The bio-chemical view goes back to the pioneering work of Hoffer and Osmond in the late 1950s, and was strongly reinforced by Pauling’s seminal 1968 paper on orthomolecular psychiatry. Surely even the most pedestrian parallelist ought to have stumbled over Pauling’s rather large milestone.

It may be that understanding mental illness in physical terms would be deplored by Szasz’s disciples as supporting the “therapeutic state” and “pharmacrasy”, but there is nothing inherently anti-libertarian about it. It is merely an attempt to explain how things work. From this position it does not automatically follow that the mentally ill should be treated against their will. (On the other hand, the position does not exclude coercion; but at least, if a government psychiatrist were to mandate my institutionalization, I would prefer having niacinaminde shoved down my throat rather than phenothiazines.) The mind-brain identity theory may or may not be true. It cannot be proven formally any better than the alternatives. If true, it conflicts with some widely held, reasonable assumptions, such as reductionism, with its implication that the whole is no greater than the sum of its parts. If reductionism is true, and people are made entirely of atoms, and no atoms possess mental properties, then people cannot have mental properties. Since they obviously do, at least one of the preceding premises must be false. The converse of reductionism is emergentism, the idea that complex systems possess properties that are not predictable from knowing everything about the component parts. Emergentism is inherently attractive to holistic practitioners, and it does permit human beings to be made of non-sentient atoms, but it brings its own set of philosophic headaches.⁴ Fortunately, as the history of science has amply demonstrated, a theory does not need to be perfectly true in order to be useful, that is, to provoke thought and stimulate research. The mind-brain identity theory has done just that. We may never know exactly what stuff our minds are made of, but we know how to use them. Using them in the framework of the brain-mind identity theory has yielded an understanding of mind-body interactions that has had the practical result of making us better doctors.

In addition to giving physicians sharper tools, another consequence of viewing mental phenomena as subsets of physical phenomena is blurring of the distinction between mind and body. Findings from the nascent science of psychoneuroimmunology, such as the pervasive non-neurologic relevance of neurotransmitters, underscore the artificiality of the mind-body distinction. In recent years, more than a few orthomolecular psychiatrists have widened their compass to the point of calling themselves orthomolecular physicians. Even the title of this Journal, which used to be Journal of Orthomolecular Psychiatry, reflects the trend.

That trend will accelerate as we become more informed on how mental and physical phenomena influence each other. We might come to regard Schopenhauer’s “world knot” as an entertaining but fairly irrelevant diversion for philosophers. Ironically, we could even end up agreeing with Szasz about mental illness, but not for his reasons: the qualifying word “mental” might someday seem just too trivial and too narrow for discussing the health of the mind-body unit.

References:

Melnechuk T: A diagnosis and a prescription. Advances, Spring 1984; 1(2):61-63
Sullum J: Curing the therapeutic state: an interview with Thomas Szasz. Reason, July 2000; 32(3):26-34
Huemer M: What is the mind/body problem? [Undated], http://www.rci.rutgers.edu/~owl/ mind.html
Huemer M: The philosophical complaint against emergence. 1992, ibid., /emergence.html