The mind-body problem is a very old philosophical dilemma. What is the connection between this enigma and the concept of mental disorder?
Stated briefly, the mind-body dualism could be explained in a form of a question: Is there a relationship between the mind and the body, and if there is some kind of a relationship, what is it?
The mind-body problem, of course, only exists if we subscribe to dualism as a philosophical perspective from which we construe the world and are trying to make sense of it. Contrary to monism, which tries to eliminate the mentioned dichotomy, dualism emphasizes how consciousness and brain are interwoven and separate at the same time. In modern times, this problem was addressed by René Descartes, who reached the conclusion that the nature of the mind (which is non-extended thus mental) is something rather different from nature of the body (which is extended and physical).
However, after defining such a problem, the burning question to this day remains: How can something non-physical and non-extended (the mind) cause change in something physical and extended (the body)? Also, vice versa: How can the body feel the sensations of the mind?
In order to interact with each other, extended and non-extended, body and mind, must come into contact at some point. The mind and the body must meet somewhere, otherwise it would be impossible to raise an arm when one has the intention to do so. The intention of movement, which is mental and subjective and unobservable from the outside, is somehow being transformed into the very act of body part movement—which is completely physical, objective and observable. For Descartes, this was quite a problem. He postulated the mind and the body as two clearly different and separate substances, but then the problem of interaction arose, and it seems that Descartes himself was not clear as to how immaterial soul (which was the same as the mind for Descartes) can have a point of contact with something material.
How is the mind-body problem relevant for the concept of mental disorder?
With somatic disorders, it is more or less clear how biophysical events cause biophysical illnesses. But in the case of mental disorders it is(still) not possible to determine how mental states and behavior correspond to biology and the physicality of the body.
In DSM-5, mental disorder is defined as follows:
“A mental disorder is a syndrome characterized by clinically significant disturbance in an individual’s cognition, emotion regulation, or behavior that reflects a dysfunction in the psychological, biological, or developmental processes underlying mental functioning. Mental disorders are usually associated with significant distress in social, occupational, or other important activities. An expectable or culturally approved response to a common stressor or loss, such as the death of a loved one, is not a mental disorder. Socially deviant behavior (e.g., political, religious, or sexual) and conflicts that are primarily between the individual and society are not mental disorders unless the deviance or conflict results from a dysfunction in the individual, as described above.”
Maybe the central notion in this definition is that of dysfunction. As stated above, dysfunction can be a physiological, biological, or developmental process, which underlies mental functioning, and the consequent disturbance in cognition, emotion regulation and behavior reflects that dysfunction.
Dysfunction itself can be a vague concept and the borderline between function and dysfunction changes over time; moreover, the borderline is relative to who tries to posit the line between the two and where. For example, it will probably not be the same for the psychiatrist after a 20-minute diagnostic interview and for the psychotherapist who has previously emphatically listened to their client for more than a year and has tried to understand their client’s ‘dysfunction’ from his/her point of view. And not only that. The notion of dysfunction can be viewed from rather different perspectives—it will not be the same if dysfunction is understood looking through the evolutionary lenses, seen from the statistical point of view or viewed simply as a biological flaw.
The notion of dysfunction, as defined in DSM-5, is important because it posits the problem somewhere between the mind and the body, but it is not clear where exactly. Psychiatry, as a branch of medicine, must be firmly rooted in anatomy and physicality of the body, so mental disorders, which are handled by the psychiatrists, are seen as a result of or at least as connected to some somatic dysfunction/organic aberration, although DSM-5 presupposes the existence of psychological processes along with the biological. The truth is that psychiatry rarely utilizes the methodology of somatic medicine and the main problem is that it is difficult to demonstrate the link between the vast majority of mental disorders/nosological entities from DSM-5 and corresponding organic aberrations.
Indeed, in what way are the body and the mind of a person with a diagnosis of severe mental disorder connected?
As we said before, in most cases of somatic disorders it is clear what has caused them, or we can at least discern the processes in the body that are connected/correlated with the disorder. Still, some argue that even the concept of somatic disorder always carries a value component. In that sense, it is virtually impossible to extract the value component from the definition of mental disorder. But this explanation does not bring us closer to the question of how the body and the mind of the person affected with the mental disorder interact. Although the value component will be recognized, psychiatry will continue to address the issue of mental disorder as something which is ontologically real as a somatic disease, with an underlying notion that there must be something wrong with the ‘mental apparatus’ of the individual in question. And that is exactly where we must bring our attention back to Cartesian dualism: As the psychiatrist makes observations about the behavior of the sick individual, they continue to assume that there are some processes analogous or the same as the bodily processes which are responsible for the symptoms of the diagnosed disorder.
The equivalence between body and mind ‘apparatus’ is not in line with the fundamental credo of Cartesian dualism: A clear distinction between extended and non-extended, physical and mental. These two substances are qualitatively different from each other. While the physical world, including the body, can be seen as a mechanism with strict mathematical laws underneath the manifest, it is totally opposite for the mental world, where no such laws could be applicable. So, if we equate the two substances and treat them as one, we are subscribing to one form of reductionism, where all psychological processes are reduced to biology of the individual and nothing else, or are parallel to physiological processes, even when we speak about cognition, behavioral changes and developmental processes (thus using mental concepts). In this manner, our philosophical stance is determining the way we perceive and think about a specific individual in question—a person who suffers from mental disorder.
This is especially important because it cuts to the core of our assumptions behind the concept of ‘the person’—and that is the agency and intentionality. If everything that we think and do can be reduced to biology or if it can be viewed mechanically as some sort of ‘mental apparatus’, then mental disorder is out of control of the individual who suffers from it, and the only way to help him or her is to treat them with pharmaceuticals. If, on the other hand, there is some sort of clear distinction between the mind and the body, although there are also connections between the two substances, then we can claim that people with psychiatric disorders can also help themselves, but we can also discuss the role of their unique autobiography and their past traumas in the creation of their mental disorder.
There is ample evidence now that the mind and the body are intrinsically intertwined in many complex ways and that simple causal connections (or mental-physiological parallelism) are not of much use. Of course that the changes in our brain and central nervous system (the body) can affect our behavior and mental states (the mind) and vice versa, but the connections, influences and cause-effect relationships are not as simple as people ONCE thought they were. In order to understand mental disorders, we have to put more effort into truly understanding mind-body as one single complex system, where it is not always clear how one influences the other. This also means that the meanings which a diagnosed individual ascribes to the specific mental disorder, along with his/her unique life history and personal narrative, are crucial for understanding the mental disorder and helping individuals who suffer to get better.