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The National Institute of Mental Health (NIMH) has begun a program to better study, prevent, and treat mental disorders.

National Institute of Mental Health

Classification of mental disorders in the United States relies on the Diagnostic and Statistical Manual of Mental Disorders (DSM), published by the American Psychiatric Association. The current version is DSM–5, which was published in 2013. DSM–5 uses very specific psychological signs and symptoms as the main determination for diagnosing a mental disorder.

As noted by Cuthbert and Insel (2013), whereas significant advances have been made recently in terms of reducing the rates of traditional medical problems such as cardiovascular disease, the same prevention and reduction have not been seen in relation to mental disorders. The National Institute of Mental Health (NIMH) has begun a program to better study, prevent, and treat mental disorders. One important aspect of this program is to develop a new way to classify mental disorders, referred to as Research Domain Criteria (RDoC).

In order to create a classification system, four steps were emphasized. The first was to identify the fundamental behavioral components such as affect regulation or executive functions that go across a number of disorders. The second was to identify the full range of human functioning. By doing this, variations in normal functioning can be used to identify psychopathology. The third step was to identify reliable and valid measures that can be used in research and treatment. The fourth step was to bring together components from a number of levels including genetics, brain functioning, behavioral aspects, and environmental aspects to describe the mental disorder.

In contrasting the NIMH RDoC approach to that of the DSM, Bruce Cuthbert and Tom Insel (2013) suggest there are seven significant differences.

1 Rather than beginning with a symptom-based definition as in the DSM, RDoC begins with the function of normal human processes. By examining the normal, it is possible to determine what is a variation from the normal range of functioning that would be considered a mental disorder. Also, by starting with normal functioning with its long history of research, it will be easier to identify underlying mechanisms seen when normal functions are no longer present.

2 Since RDoC emphasizes the full range of human functioning across a number of levels, mental disorders will be described in terms of dimensional components. In general, the DSM emphasizes categories such as major mood disorder, personality disorder, PTSD, or generalized anxiety disorder. DSM–5 has begun to consider dimensional aspects such as autism spectrum disorder, but a number of disorders remain as categorical; you either have the disorder or you do not.

3 The third point emphasizes the reliability and validity of measures of human functioning. By using a dimensional approach, research can better note changes along the entire range of human functioning. In medicine, presenting blood pressure measurements along a continuum has allowed for advancements in the field in terms of who needs to be treated and at what level. For example, research suggests that those over the age of 60 may experience a higher blood pressure before treatment is needed than those who are younger (James et al., 2014). Looking at levels of anxiety and depression by studying their underlying components on a continuum would better identify who needs treatment and at what age.

4 The fourth point is related to how the DSM–5 and RDoC dictate the type of research design that is used. DSM research typically uses the diagnosis category as the independent variable. For example, individuals with anxiety according to the DSM are compared with a control group of individuals without anxiety. RDoC does not allow this type of approach. RDoC begins with a selection procedure. You might begin by looking at everyone who presented themselves at a VA clinic focusing on the treatment of PTSD. Another approach would be to study those who had experienced a trauma in the past month. You would then choose one or more independent variables that fit your research hypothesis. It could be distress, sleep, brain imaging, and so forth.

5 The fifth point relates to a search for an integrated understanding of behavioral and brain processes. This is understood in the RDoC approach to mean that both the behavioral measure and the brain measure or other physiological measure would be valid in themselves as a component of a particular disorder. The DSM, on the other hand, emphasizes signs and symptoms, without using specific neuroscience measurement techniques.

6 The sixth point reflects the different development trajectories of the DSM and RDoC. RDoC began with a focus on those disorders with solid research. Although the DSM seeks to be informed by research, the disorders included began with historical precedence.

7 Since RDoC is an experimental approach to understanding mental disorders, it can change as new information is obtained. This has less of an effect on society in terms of insurance payments, legal considerations, and the collection of prevalence rates. That is, every time diagnostic criteria for a DSM disorder changes, older studies of a disorder with different criteria must be reconsidered.

Thought Question: What are the advantages and disadvantages of DSM–5 and RDoC?