Thursday, September 24, 2009

Psychotherapy Brown Bag - A dimensional model of mood and anxiety disorders: Moving towards DSM-V

Michael D. Anestis takes an intriguing look at some possible changes in the DSM-V views of mood and personality disorders. As someone who will be coming into the field just as the DSM-V is released, I find this all very interesting. These are only proposals, so what do you think about them? Are they useful?

The first article, which I am posting here in full, looks at mood disorders (Axis I), the second one, which I am only linking, looks at personality disorders (Axis II).

A dimensional model of mood and anxiety disorders: Moving towards DSM-V

New M.Anestis Photo Compressed

by Michael D. Anestis, M.S.

In May 2012, the fifth version of the Diagnostic and Statistical Manual of Mental Disorders (DSM-V) is due for publication. As has been the case each time the DSM - our guideline for mental health diagnostic decisions - has approached revision, substantial controversy exists regarding the changes that should be made. In the first two versions of the DSM, mental illnesses were described in vague paragraphs that made assumptions regarding causes (e.g., unconscious conflicts from childhood) often based upon the scientifically weak theories of psychoanalysts. Beginning with DSM-III in 1980, a greater emphasis was placed upon reliability, with specific symptoms based in large part upon observable behaviors taking precedent in an atheoretical system. The system was further refined in subsequent years, leading to our current version, the DSM-IV-TR. Despite substantial improvements in the validity and reliability of diagnoses, the DSM still has many problems and, as a result, researchers and clinicians have been campaigning for various shifts, some more radical than others, in our approach to conceptualizing mental illnesses.

This article will by no means touch upon all of the controversies surrounding the creation of the DSM, nor will it effectively summarize all of the strengths and weaknesses of our current system. Instead, the goal is to provide a description of an article recently published in Psychological Assessment by the eminent scholars Timothy Brown and David Barlow (2009) of Boston University that details their proposal for a new diagnostic system for anxiety and mood disorders.

The Problem - Weaknesses in the Current Diagnostic System

Brown and Barlow (2009) opened their article by explaining the various weaknesses of the DSM-IV-TR, with the aim being to emphasize the areas in which DSM-V needs to provide tangible improvements. Along these lines, the authors noted that, while the reliability of the current DSM is a marked improvement over earlier versions, there are still several sources of problems in this area. They cited a study by Brown, DiNardo, and colleagues (2001) in which participants were administered structured clinical interviews by two different clinicians in order to determine the degree to which the clinicians would agree on diagnoses. The goal, of course, was to determine how reliable the DSM diagnoses actually were. Although the results were fairly strong, they noted six distinct sources of error:

  1. Clients often reported different information to the different clinicians. This reduces reliability because the clinicians are not left with the same information from which to work.
  2. Clients reported identical information to each clinician, but the clinicians disagreed on whether or not the symptoms caused sufficient distress and/or impairment to justify a diagnosis
  3. The clients' symptom levels actually changed between interviews, thereby leading to legitimate disagreements
  4. The clinician improperly applied the DSM diagnostic rules and thereby arrived at improper diagnostic decisions
  5. The clinicians disagreed on whether symptoms of one disorder were better accounted for by another diagnosis
  6. The DSM itself was unclear in its description of symptoms, thereby hindering differential diagnoses

In addition to reliability problems, Brown and Barlow (2009) noted that the current DSM exhibits problems with comorbidity. When an individual has comorbid diagnoses, this means that they meet criteria for more than one diagnosis at the same time. As it turns out, comorbidity is the rule, not the exception. In other words, clients meet criteria for multiple diagnoses more often than they meet criteria for only one. At first glance, this might not seem like much of a problem. After all, this might simply reflect the fact that different disorders often cluster together. A closer examination of the phenomenon, however, reveals several problems that emerge from this situation. For instance, Brown and Barlow (2009) noted that the comorbidity of social anxiety disorder (SAD) and depression is, in large part, accounted for by the fact that both disorders are characterized by low trait levels of positive affect. In other words, it might not be that these two distinct phenomena co-occur but rather that both the symptoms of depression and SAD are, in large part, accounted for by the general tendency to experience chronically low levels of positive emotions and that making the distinction between the two different disorders is less important than emphasizing the shared characteristic.

Brown and Barlow (2009) also noted that the high levels of comorbidity in the current DSM might actually cause clinicians to understate the presence of certain symptoms. For instance, Brown, Campbell, and colleagues (2001) found that the presence of panic disorder was predictive of decreased risk for SAD and specific phobias. Given that all three disorders share several important characteristics, including avoiding feared situations, this was surprising. The explanation, however, is quite simple, The DSM diagnostic rules often lead clinicians to assume that symptoms of diagnoses such as SAD and specific phobias are better accounted for by other diagnoses such as panic disorder and, as a result, the client's list of diagnoses does not make any mention of clinically impairing symptoms that are associated with the other disorders.

Brown and Barlow (2009) saved their strongest criticism of the current DSM for last. As it currently stands, the DSM calls for categorical diagnoses. In other words, you either have a diagnosis or you do not. With the exception of depression, which allows for specifiers such "severe" or "mild," there is no description of severity in any DSM diagnoses. Importantly, the decision to use a categorical system and the number of symptoms required to meet the cut point for each diagnosis are not based on empirical research. In other words, an arbitrary line was drawn by a committee to determine whether or not an individual meets criteria for a mental illness. Now, to be fair, the DSM also includes "not otherwise specified" diagnoses, which allow clinicians to still provide a recognized diagnosis to an individual who is obviously distressed or impaired but who does not meet criteria for a mental illness, but the arbitrary nature of the cut points is an obvious issue nonetheless.


The Proposed Solution - Brown and Barlow's (2009) Idea for a New Approach

Having established that the current version of the DSM is imperfect, Brown and Barlow were left to offer up something better. After all, it is easy to be a critic, but the real value rests in the ability to provide incrementally valuable alternatives capable of improving the situation. Simply tearing apart imperfections does little to help anyone and, remember, this entire field exists to provide effective care to individuals suffering from very real problems. Fortunately, neither Brown nor Barlow were interested in being mere critics and, while we can certainly debate the value of their proposed system, it is worth taking a look at what they propose in order to figure out where the field might be heading and what the best possible solution might be.

Quite frankly, the system proposed by Brown and Barlow (2009) is complex and the article in which they described the system was fairly dense, so my efforts to explain their thoughts here come with the disclaimer that, in order to fully understand the concepts, your best bet is to read the actual article. That being said, their system essentially boils down to ditching our current system of diagnostic categories for mood and anxiety and instead measuring the degree to which individuals exhibit elevations on particular variables known to relate to mood and anxiety disorders. Specifically, they propose considering:

  • Anxiety/neuroticism/behavioral inhibition (A/N). In other words, the degree to which the individual experiences chronically elevated levels of negative emotions and demonstrates a tendency to inhibit prepotent responses.
  • Behavioral activation/positive affectivity (BA/P). In other words, the degree to which an individual tends to engage in approach behavior and to experience chronically elevated levels of positive emotions.

Research has shown that individuals experiencing anxiety disorders as well as depression tend to exhibit highly elevated levels of A/N. Additionally, depression and SAD tend to involve low levels of BA/P and mania involves high levels of BA/P. In other words, all of these disorders are related to particular combinations of these variables and, as such, developing a profile of the degree to which an individual exhibits high or low A/N and BA/P could provide a more comprehensive picture of what is going on with a client than we can get from a simple yes/no decision regarding whether or not the client meets criteria for one or more diagnoses.

Simply looking at these two variables, however, does not give us enough information. After all, if SAD and depression are characterized by similar patterns of A/N and BA/P but are also characterized by different symptoms and outcomes (e.g., suicide risk profile), then we need to know more about what is going on with the client. Brown and Barlow (2009) thus propose that we further assess the presence, severity, and frequency of avoidance behaviors and examine the functional relationships of A/N with the characteristics traditionally associated with particular diagnoses.

So, Brown and Barlow (2009) see mood and anxiety disorders unfolding as follows: an individual has genetically predetermined levels of A/N and BA/P. In the presence of life stress, specific features of classic diagnoses are triggered and become evident, resulting in clinical distress and impairment. Importantly, although specific factors (e.g., intrusive thoughts) are often associated with one particular diagnosis (e.g., OCD), they often appear in other disorders as well, so assessing for their presence instead of just assessing for diagnoses would allow clinicians to better understand everything going on with each client. Brown and Barlow (2009) listed the following as specific features that should be assessed:

  • Fight or flight response: when triggered inappropriately, this results in panic attacks. Panic attacks themselves often become the central focus of A/N.
  • Somatic symptoms: the degree to which the individual is focused on unexplained physical symptoms and/or sensations of unreality associated with dissociation.
  • Ego-dystonic intrusive thoughts: the degree to which an individual experiences unwanted and aversive thoughts (e.g., thoughts of harming one's own children).
  • Social evaluation: the degree to which an individual exhibits a fear of being negatively evaluated by others
  • Past trauma: the degree to which an individual focuses on or responds strongly to (e.g., flashbacks) cues of a past traumatic event

Pulling it All Together

Brown and Barlow (2009) thus propose that, when a client presents at a clinic, he or she should be assessed for levels of A/N and BA/P. This will provide a basic profile of their vulnerability to traditional mood and anxiety disorders. Furthermore, the clinician should assess the presence, severity, and frequency of avoidance behavior and the degree to which the client is exhibiting the specific features listed above. So, in the end, the client does not receive a diagnosis, but rather a description of the degree to which he or she maintains particular levels of negative and positive emotions as well as the specific manner(s) in which his or her emotions manifest in response to stress.


What is the Purpose of All This?

The idea here is to ensure that our assessment provides us with the optimal amount of information about the client and his or her struggles rather than focusing too narrowly on arbitrarily designed categorical diagnoses that might leave out important information relevant to treatment approaches. This system would remove the need to make differential diagnoses that cause one diagnosis to be subsumed within another and would no longer overlook the clinical implications of subthreshold symptoms.

Are there potential pitfalls to this system?

Here is where my article diverges a bit with the Brown and Barlow (2009) one. The authors noted that clinicians might be hesitant to utilize this system because it is relatively complex and unfamiliar. They also noted that, as of now, there is no single empirically tested assessment measure capable of performing the tasks they recommend and, as such, we have no research upon which to base the cut points that would be needed in order to inform insurance companies regarding the need for services. I agree with all of these critiques.

What they did not spend much time discussing - and to be fair, they could not discuss everything in depth in a single article - was the impact this would have on empirically supported treatments (ESTs). ESTs have been developed for several disorders. Although various forms of cognitive behavioral therapy (CBT) work for essentially all of the disorders involved in this new system, other forms of therapy such as interpersonal psychotherapy (IPT) have not been validated on all of the diagnoses. As such, it becomes unclear when each treatment would be most useful. The authors proposed that we develop transdiagnostic treatments and noted that they had developed one based upon CBT, but in doing so, we will be left without the mountains of prior work implicating particular treatments for specific diagnoses. We would have to essentially start over, which can take a very long time. The end result might be better, but we would be assuming substantial risk and would be left with a transition period certain to cause a significant amount of confusion and unrest both within and without the professional community.

So is this the answer?

Well, Timothy Brown and David Barlow are both substantially more informed on these matters than I am, but I find myself undecided on the best course. Data indicate that many disorders are dimensional in nature, so I am very much in favor of a system that measures severity of illness and assesses all symptoms. At the same time, I am a huge proponent of ESTs and am skeptical of any approach that would leave us without the benefit of all the work that has led us to this moment. Additionally, I am not convinced that a dimensional system will result in cut points that are any more valid that those that have currently been established and I can not help but fear that insurance companies would utilize their own cut points that minimize the likelihood of clients receiving effective mental health care.

The bottom line is, there will be no perfect answer. The question is how to best ensure incremental improvements in DSM-V that allow for more valid and reliable diagnoses and an easier path toward empirically supported care.

Your thoughts?

Where do you see the DSM-V going? Do you like Brown and Barlow's model? What do you think are its pros and cons? Even if you think it is the best system, do you think it could be effectively implemented in every day practice?

If you would like to learn more about the DSM and current conceptualizations of mental health and psychotherapy, we recommend the following resources, all of which are available through our online store:

Mike Anestis is a doctoral candidate in the clinical psychology department at Florida State University

Now, go read A dimensional model of personality disorders: Moving towards DSM-V, the more interesting of the two articles for me.

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