Psychiatry is the practice of treating mental disorders and psychiatric taxonomy is a branch of it. In their article “Psychiatric Disorders: A Conceptual Taxonomy”, Peter Zachar and Kenneth S. Kendler explain the following conceptual dimensions where psychiatric taxonomy, or psychiatric taxonomic syndroms can be located:
- Internalism vs. Externalism
- Objectivism vs. Evaluativism
- Casualism vs. Descriptivism
- Essentialism vs. Nominalism
- Entities vs. Agents and
- Categories vs. Continua
The aim of the authors has not necessarily been to establish their theory but to provide a frame work or guideline for future discussions on the subject. The article mainly describes Internalism vs. Externalism, viz.:
- Are psychiatric disorders occurring in organisms solely due to internal processes (Internalism) ?, or
- Are external occurrences playing any important role in psychiatric disorders (externalism)?
If one considers that external or environmental occurrences can cause psychiatric disorders, or mental illness, then he/she is a causal externalist. On the other hand, if one considers that the external occurrences affect one’s neurological state, which causes mental illness, he/she may be a proponent of constitutive internalist. In effect, according to the concept, while being a causal externalist, one can also be a causative internalist.
Review of the Article “Psychiatric Disorders: A Conceptual Taxonomy”
Internalism versus externalism and objectivism versus evaluativism are the two important dimensions stressed by the authors’ framework to analyze psychiatric taxonomy in this article. Internalism, as we saw, is the concept according to which psychiatric disorders occur solely due to internal processes. On the other hand, externalism concept states that external occurrences play an important role in a person’s psychiatric disorder. What are evaluativism and objectivism? Evaluativism is a particular type of constitutive externalism which essentially involves a value added judgment. Objectivism is just deciding whether a psychiatric disorder is a factual matter or not. For example, consider someone experiencing internal voices. While this is not a pathological case, from an objectivist angle, this is a factual claim. On an evaluative view, how experiences are valued forms a constitutive element. These dimensions lead us to constitutive externalism and constitutive evaluative externalism.
Zachar and Kendler explain that events within the body serve as critical factors to understand and define psychiatric disorders. While externalists believe that a person’s interaction with the world cannot be isolated from what goes on in his mind. Modern psychiatry largely believes in internalist theory. While medical models claim that mental illness is due to internal events, the externalistic model shows that there are several cases of mental illness arising from externally disturbed relationships. The constitutive internalist’s view holds good in this context, because this instance is consistent with the causation occurred due to the intervention of the brain. Similarly, one cannot rule out a brain-mediated central role in peoples’ interpersonal contexts as well as in their responses to the external world.
Constitutive externalism in mental health is radical in nature. The advocates of this theory hold that internal events are less relevant than what happens outside the skin. In the historical contexts, constitutive externalism is seen as psychogenic psychosis. Research shows that external events are definitional. As explained earlier, causative evaluativist externalism constitutes a value judgment. According to this school of thought, due reasoning is made and evaluated as to why something is a psychiatric disorder. As for value judgment, Zachar and Kendler take pain to explain how advocates of change and slaves, who had a compulsion to run away, were treated as mentally ill in the former Soviet Union. In the eyes of the objectivist, those classifications were based on bad values and were progressively eliminated. As this led to opposition, better values were adopted.
Based on the medical models of psychiatric disorders, the authors of the article have described four prominent disorders, namely the Organic Disease Model, the Altered Function Model, the Biopsychosocial Model, and the Harmful Dysfunction Model that adopt positions on any of the conceptual dimensions, such as internalism vs. externalism, essentialism vs. nominalism, causalism vs. descriptivism, objectivism vs. evaluativism, entities vs. agents, and categories vs. continua. Apart from these four medical models, there are several Alternative Models of Psychiatric Disorders, such as Dimensional Models, the Practical Kinds Model, the Inter Personal Models, etc., which also adopt positions on the dimensions.
This article by Peter Zachar and Kenneth S. Kendler has been exhaustive on the subject. They have made comprehensive analysis of dimensions along which the various models of psychiatric disorders have to be viewed. The authors also have described the dimensions of categorization and models of psychiatric disorders in a consolidated and balanced manner. They have gone very deep into history and genesis of psychiatric disorders. Their study has brought forth definitive criteria for diagnosis of psychiatric disorders. Although the study has been comprehensive, the authors still feel that psychiatric disorders have to be studied more usefully from an “essentialist perspective” in future (Zachar & Kendler, 2007).