A new Diagnostic and Statistical Manual of Mental Disorders (DSM) is in the works and will be ready for publication in 2013. The DSM is used by mental health professional primarily in the United States to diagnose patients with mental health disorders, such as schizophrenia, bipolar, and depression. Dr. John Sorboro, a psychiatrist, wrote an article for Skeptic Magazine1 questioning the need for a new DSM (the DSM V) while criticizing the current one (the DSM IV-TR). His problems with the DSM are many, and he uses some analogies to incite a reaction, even if negative (e.g., comparing the DSM to the ‘Malleus Maleficarum’ aka ‘The Hammer of Witches’), but he does also make some valid points. In my opinion, the most important problem he points out is that there is an issue with a manual that uses strictly symptomology (most of it revealed subjectively) to diagnose a disorder, which is how the DSM works. Here’s his basic argument. Psychiatric disorders are constructs, models based on observations that fit a specific theoretical framework. In psychiatry, the Major Depressive Disorder (MDD) construct is defined by its symptoms2 (shown below):
Must have at least 5 of these symptoms for at least two weeks:
- Depressed mood for the majority of the day on most day
- Loss of interest in most activities (otherwise known as adhedonia)
- Insomnia or hypersomnia
- Decreased concentration
- Increased fatigue or decreased energy for the majority of the day on most days
- Feelings of worthlessness
- Psychomotor agitation or retardation
- Suicidal ideation
Dr. Sorboro points out that several of these symptoms overlap with symptoms of other disorders, for example, Attention Deficit Hyperactivity Disorder (ADHD). A symptom of MDD such as decreased concentration could be misconstrued as being caused by ADHD, inaccurately assumed to fall under the category of inattention (with symptoms such as distractibility, difficulty finishing tasks, not engaging in tasks requiring significant effort and attention, etc). Even a symptom of MDD such as psychomotor agitation could look like a form of hyperactivity (also found in ADHD). The point that Dr. Sorboro makes is that there are good constructs and bad constructs. For example, the good ones are like Parkinson’s disease, where the symptoms are specific, such as tremor, rigidity, and bradykinesia and are associated with the loss of neurons in the Substansia Nigra. The bad ones are like fibromyalgia with more vague symptoms such as muscle pain, fatigue and insomnia but not accompanied by specific pathology. With such general symptomology and no specific pathway, fibromyalgia suffers from validity issues. How do we know that the symptoms are in fact caused by fibromyalgia and not something else? The same goes for depression. How do we know that these are symptoms of depression rather than ADHD or something else? This is one reason why Dr. Sorboro says these disorders are bad constructs. With good constructs like Parkinson’s, there is research showing that some anti-psychotic drugs, which target dopamine and inhibit its release, produce Parkinson-like symptoms. We treat Parkinson’s with L-DOPA, which when given systemically, is broken down in the blood brain barrier into dopamine, which reduces these symptoms to a certain extent. In the case of fibromyalgia, general muscle pain, fatigue, and insomnia are not uncommon to other disorders, as well. Dr. Sorboro in his article says that one of the doctors, Dr. Frederick Wolfe, that helped define the diagnostic guidelines for fibromyalgia actually now denies that this disorder is a valid construct, and he supports the idea that it results from stress, depression, and social anxiety. Dr. Sorboro contends that groups within the field and outside the field of psychiatry question psychiatric constructs in the same manner as fibromyalgia is questioned.
I’m not denying that these disorders exist. I think they do. In reality people really do feel different, meaning that something is occurring in those afflicted with mental health disorders that is not occurring in those who are not afflicted. What the underlying factor is, however, remains to be elucidated. That said the real key is to discover neurobiological underpinnings and target biomarkers in order to aid in the process of diagnosis.
When I go to a medical doctor, I describe my symptoms, which help the doctor to diagnose my illness. However, it does not stop at my subjective experience. The doctor will then check for physical signs of illness and maybe even take some samples of blood or saliva to send to the lab for analysis. All of these together (subjective experience, doctor examination, and lab tests) are considered in the final diagnosis. Sure, assumptions are made almost immediately as to what the illness is, based on the doctor’s experience with these symptoms previously seen in other patients or based on an educated guess by the doctor formulated from material studied at some point or another, but the tests either confirm or don’t confirm the assumption. There are no physical evaluations or lab tests in psychiatry to confirm the assumption. There is only the experience and the observation leading to an assumed diagnosis. This is a problem. We should not continue to rely on symptomology to be the main tool in diagnosing a patient. There needs to be a shift in focus to underlying pathologies of mental health disorders. Dr. Sorboro’s article in Skeptic seems to deny (or possibly just ignore) that there has been significant progress in the pathology of mental health disorders, and that there has only been progress strictly in the efficiency of diagnosing and number of diagnoses we have at present. However, this is mainly an attack on psychiatry and the DSM, but the research community has made significant progress discovering pathology in mental health disorders.
For example, Sharpley and Bitsika, in a review3, report the findings from several years of research on the neurobiology of depression. They report that depressed patients have been found to have an insufficient supply of monoamines (e.g., serotonin and noradrenaline), which are broken down in the synaptic cleft by monoamine oxidases. This led researchers to develop anti-oxidising agents for depressed patients, revolutionizing the treatment for MDD. Further research found that specific neurotransmitters could be targeted (e.g., serotonin re-uptake inhibitors or SSRIs), inciting the production of even more medications for MDD. Sharpley and Bitsika talk about other research showing that depressed mood may be associated with dysfunction in the lateral prefrontal cortex, hopelessness with dysfunction of the hypthalamic-pituitary-adrenal axis, and psychomotor agitation and sleep problems with dysfunction in the thyroid axis. In addition to this research, a recent review by Schmidt et al.4 outlines some biomarkers that are found at abnormal levels in the depressed individual. These include growth factors, cytokines, endocrine factors, and metabolic markers. They claim that these are potential targets for tests of confirmation in patients seeking help for depression. Of course, they admit to some limitations, and that time, money, and effort are needed to be able to use these biomarkers as diagnoses tools, however, this type of research could be groundbreaking in how we diagnose and treat patients in the future.
Even though I see significant research strides in the area of mental health disorders, I share the frustration of Dr. Sorboro regarding the field of psychiatry and the DSM. One of the main problems I see is that the new DSM V will be published before any of these biomarker tests are ready, and it will not focus on the neurobiology of these disorders. The new version appears only interested in revisions of criteria for existing disorders and adding even more additional, more specific disorders, such as ‘Internet Addiction Disorder’ and ‘Compulsive Shopping Disorder’ as examples. True, this may lead to better, more personalized cognitive therapy treatment, however, it is completely disregarding that these two disorders listed above may have very similar neurobiological pathways related to addiction in general. Therefore, they would be treated similarly at a pharmacological level, although there may be different behavioral therapy interventions utilized. Regarding the field of psychiatry there is another issue. As a neuroscientist in training, I tend to think in terms of underlying neurobiology, at least partially, causing whatever abnormal behavior is present in an individual, however, a psychiatrist trained as a medical doctor wouldn’t necessarily think in this manner. They have minimal training in neuroscience, and since psychiatry is concerned with abnormal behavior that, from what I’ve learned, originates in the brain, it might be helpful to have medical students who want to become a psychiatrist focus on neuroscience classes and research during their early years. I went to the psychiatry website for the university I attend. Taking a look at the psychiatry requirements5, I found out that psychiatry med students do not differ that much (besides a 27 hr course in year one and a 20 hr course in year two) from other colleagues until residency. Residency lasts four years, and during this four-year period the resident’s first two years focus on inpatient and the third year on outpatient. Then, during the fourth year, there is an opportunity for an “intensive research experience.” But, I think that’s too late in their training. By that time, I would think there would be little interest in research, and I would be curious to know the percentage of medical school residents that choose that option in their fourth year.
In any case, I would hope that diagnoses by psychiatrists using symptomology alone won’t last. Too much research is being done that will continue to be covered in mainstream media as hot topics leading to patients wanting to know more about specific physical tests that can be used to really pinpoint the problem. This is especially true of fMRI research. Until the time when physical tests are used for confirmation we, like Dr. Sorboro (a psychiatrist in the field), should remain questioning of symptom-based diagnoses and continue to push for the uncovering of core mechanisms contributing to the abnormal behavioral state of individuals with mental health issues. They deserve to be treated in the most effective way possible. Mental health abnormalities are not like cancer, where we know the enemy well, yet just haven’t yet developed the most effective weapon. With mental health disorders, it is as if we don’t know our enemy but are still developing weapons and using them blindly; hoping to hit our foes while missing our allies.
References:
1. American Psychiatric Association (2000) Diagnostic and statistical manual of mental disorders. Fourth Edition. Text Revision. p. 356
2. Schmidt, HD, Shelton, RC, Duman, RS (2011) Functional biomarkers of depression: diagnosis, treatment, and pathophysiology. Neuropsychopharmacology, Aug. 3, 1-20.
3. Sorboro, John (2010) Prognosis Negative: Psychiatry and the foibles of the diagnostic and statistical manual V (DSM-V). Skeptic, 15(3), 44-49
4. Sharpley, CF, Bitsika, V (2010) Joining the dots: neurobiological links in a functional analysis of depression. Behavioral and Brain Functions, 6:73, 1-9
5. University of Minnesota. Department of Psychiatry. http://www.psychiatry.umn.edu/education/home.html
No comments:
Post a Comment