How We Think About Mental Health Disorders (Part 2): Categorical vs. Dimensional
As I mentioned in my first post on this topic, the way we talk about mental health disorders and their reality are often different. My last post discussed how we think about "normal" vs. "abnormal" in terms of thoughts/feelings/behaviors, and how that helps to determine what qualifies as a mental health disorder. But there is still a big problem that needs to be addressed: once something is found to be "abnormal," how do we define what condition is the best fit for a person? Here, I want to talk about the two main competing approaches in psychology.
The categorical approach is one that is familiar to most. This approach gets its name because people are put into pre-set categories; mainly, someone either has a condition or they do not. With this approach, there is little room for gray areas, and people are determined to fit into a category of a diagnosis based on pre-determined criteria (which are provided in the DSM).
Before we get into the obvious challenges that come with the categorical approach, let's consider how it is useful. After all, the categorical approach is still used today, so there must be a reason.
The main advantage of the categorical approach is the clarity (or at least it seems clear). By using the categorical approach, and the diagnoses that come with it, we can summarize the challenges a person is experiencing in a brief list. This can be considered as "getting to the point," and also helps to keep things streamlined. It's helpful for things like billing, but it can be problematic in clinical practice.
The main problem is that reality is much more inconsistent than the categorical approach would like to suggest. For example, two people struggling with depression can have very different symptoms, but still be classified the same way. Some people have more severe forms of conditions than others, but these levels of severity can be lost. (To be fair, the categorical approach allows for some indication of severity, such as mild/moderate/severe, but it still simplifies the reality).
There are also a lot of things that aren't taken into consideration with the categorical approach. For example, it doesn't communicate anything about the social situation a person is in, how their relationships and culture may play a role, and so forth. Ideally a clinician takes these into account when determining the category, but they aren't communicated to others well.
The main alternative to the categorical approach is what's known as the dimensional approach. In this framework, symptoms and conditions are viewed as being on a spectrum. Rather than people being reduced to categories, they are a combination of different symptoms with varying levels of severity among those symptoms.
A good demonstration of this idea is the Genderbread Person. In this diagram (see below), different components of gender and sexuality are shown as scales ranging from non-existent to high. In theory, each person has a slider somewhere along those dimensions, and that all combines together to form a part of who that person is.
The same can be thought of for mental health disorders. For example, with depression there can be varying levels of fatigue, sadness, anhedonia (lack of pleasure in things that used be enjoyed), sleep disturbance, and so forth.
As most psychologists will likely agree, the main advantage of the dimensional approach is that it allows us to think about a person in a much more realistic way. People suffer from different levels of symptoms at different times, and this framework allows for that shifting and inconsistency from person-to-person. In addition, there is some flexibility in what gets taken into consideration, so focus can more easily remain on the most important things.
Despite the attraction and utility of the dimensional approach, there are some challenges associated with it. For one, it's difficult to determine actual levels of where people are on any given scale. Second, it's difficult to communicate a summary of a person to other professionals, as the dimensional approach essentially requires a detailed explanation of everything happening (there are no groups of scales for professionals to use visually that I know of). Third, it allows for communication of more information than the categorical approach, but still does not necessarily make it easy to communicate more complex things like social situations.
Neither system is perfect, and there is definitely room for improvement. From my experience, the categorical approach is mainly utilized as a summary of patients (for other clinicians) and for billing purposes. The dimensional approach is useful for trying to think about a summary of a person clinically and to determine what treatments might be helpful. However, there is always a need to take into account the context of a person, which is done by the clinician and helps to determine the final treatment plan.
In the end, the different approaches are used at different levels of care, and they by no means represent the totality of any given person who comes in for therapy. So if you see people using categories/diagnoses and dimensional approaches to discuss clients, please don't get the impression that those summaries represent our full understanding of a client. There is always so much more to the picture.
Have questions about how we conceptualize clients? Do you have thoughts about how the system could be improved? Let me know in the comments!