Does Anxiety Plus Depression Equal Depression Plus Anxiety? How Clinicians Really Think
Imagine that you take your car into the shop because it's been acting a little funny lately. The mechanic listens to your concerns and takes a look at your vehicle. He tells you that your car has a dent in the fender and also a failing transmission. He suggests fixing the fender right away because that's the first issue you mentioned to him, so he assumes it's the most important to you. In other words, a fender bender plus a failing transmission is not the same as a failing transmission plus a fender bender.
How would you respond? My guess is that you would ask the mechanic if he'd been spiking his coffee that morning. A dented fender versus a transmission about to go kaput? Hmmm - although I'm not as knowledgeable as the guys on NPR's Car Talk, I certainly know that fixing a car's transmission is more crucial than pounding out a little dent. Luckily, this silly example is not very similar to how many clinicians approach their work in mental health.
I recently read about a fascinating study exploring how mental health clinicians conceptualize diagnoses, particularly when comorbidity exists. Comor-what? Comorbidity is a fancy word to describe two or more diagnoses existing at once. For instance, a person may experience generalized anxiety disorder as well as an adjustment disorder with depressed mood. Keep in mind that these are formal diagnoses found in the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR) - the book used by mental health professionals to code diagnoses on client records.
The study looked at whether clinicians used the commutative property implied in the DSM-IV-TR to make diagnostic decisions. The commutative property is an algebraic concept that purports that A + B = B + A. This works well for concrete subjects - for instance, oranges. Four oranges plus three oranges is the same as three oranges plus four oranges. Either way, you've got seven oranges.
But does this really work with phenomena as complex as mental health conditions? For example, if a person has a long-standing depressive disorder and then, after an acute trauma, also develops anxiety, is this person's experience the same as someone who has a long-standing anxiety disorder and then becomes depressed after the death of a spouse?
I don't think so - depression plus anxiety does not equal anxiety plus depression. The human spirit is too complicated to submit to the commutative property. Luckily, clinicians seem to feel that way, too. The study found that most clinicians place emphasis on a primary diagnosis and then also note secondary diagnoses in their case reports. Granted, this is the format often required on client records, but the DSM-IV-TR does not address how to "weigh" comorbid diagnoses or how to translate this equation to practice.
There are pros and cons to the fact that clinicians do not treat clients under the assumption that A + B = B + A. On the upside, clients are more likely to get the treatment they need for their most pressing conditions first, as long as an accurate diagnosis was made. On the downside, clinicians are subject to a host of judgment errors, such as over-emphasis or under-emphasis of certain conditions, which could result in inappropriate treatment.
The bottom line is that clinicians need to be aware of their values and tendencies when diagnosing comorbid conditions, and that clients need to advocate for themselves if they feel they are not receiving adequate treatment for their most salient mental health needs.
Keeley, J. W., DeLao, C. S., & Kirk, C. L. (2013). The commutative property in comorbid diagnosis: Does A + B = B + A? Clinical Psychological Science, 1(1), 16-29.