Problems with the Diagnostic System for Personality Disorders

No diagnostic system is perfect. Therefore, it is no surprise to us that the current DSM-5, a diagnostic system for personality disorders, is identified with many diagnostic difficulties. In this blog, we will explore the limitation of a categorical approach and the disregard of the variability of symptoms.

The DSM-5 includes two types of diagnostic models for personality disorders; one is a categorical model which is the official diagnostic method and the other is the dimensional model which is the model presented for future consideration. In the official categorical model of disorders, an individual either has the disorder or not. In contrast, the dimensional model accounts for varying degrees of severity. Therefore, we can say that the categorical model is suitable for absolute conditions while the dimensional model is suitable for conditions with a range, that are on a continuum, such as personality. The categorical model assumes that each personality disorder is a distinct category, different from other personality disorder and from normal personalities. However, dimensional model views personality disorders as the extremes on the continuum of normal personality dimensions, therefore the disorder and normal personality are not separate entities. The benefit of the dimensional approach is that we many gain greater accuracy and precision when we distinguish individuals with and without disorders by viewing the degree of expression of a specific trait rather than looking them as separate entities. But the dimensional approach is more complicated; it is difficult to decide on which dimensions are important to take into account and what level does one has to reach to be diagnosed with a disorder. By following this dimensional approach, there is definitely a trade off between accuracy and simplicity.

In addition to being categorical, the DSM-5 uses a polythetic approach, which is a method where for an individual to be diagnosed with a personality disorder, one needs to meet a certain number of symptoms in the criteria. The first problem that arises from this approach is that this system assumes that all the diagnostic symptoms carry the same weight and are equally important in making a diagnostic decision. This equality among symptoms may make the diagnostic process simpler but it may be inaccurate and allow to miss important information about the individual. Another problem is the issue of high heterogeneity. This term means that there is a lot of variation among people with the same disorder. This is problematic because then the diagnostic label becomes less meaningful and less useful to the clinicians, researchers and patients. Therefore the diagnostic labels become unreliable indicators that a particular underlying problem is actually present in the individual with the diagnosis.

By identifying and acknowledging the diagnostic difficulties in the DSM-5, now the researchers and clinicians can improve on these aspects and produce more accurate and reliable diagnostic system for personality disorders.

Reference:

Hoermann, S., Zupanick, C. E., Dombeck, M. (n.d.). Problems with the Current Diagnostic System. Retrieved from http://www.sevencounties.org/poc/view_doc.php?type=doc&id=569&cn=8

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