• Changes to the Motor Disorders in the DSM-5

    This post is part of a series of guest posts on GPS by the graduate students in my Psychopathology course. As part of their work for the course, each student had to demonstrate mastery of the skill of “Educating the Public about Mental Health.” To that end, each student has to prepare three 1,000ish word posts on a particular class of mental disorders, with one of those focusing on changes made from the DSM-IV to the DSM-5.


    Motor Disorders in the DSM-IV and DSM-5 by Tyler Whitehead

    The Diagnostic and Statistical Manual of Mental Disorders (DSM) recently underwent revisions, which changed many of the clusters of disorders.  The revisions affected some of the areas more than others.  However, motor disorders, while sustaining a few changes, did not experience extensive such alterations.  In the DSM-5, there are three main disorders: developmental coordination disorder (DCD), stereotypic movement disorder (SMD), and tic disorders, which are a subcategory of disorders of their own.  The cluster of motor disorders now fits under neurodevelopmental disorders, a new cluster of disorders.  Previously in the DSM IV-TR, developmental coordination disorder, stereotypic movement disorder, and tic disorders were under the cluster of Disorders Usually First Diagnosed in Infancy, Childhood, and Adolescence.  Additionally, the only disorder that was under the category of “motor disorders” was developmental coordination disorder.  Tic disorders were their own category and stereotypic movement disorder but didn’t really seem to have a place anywhere else, somewhat like a “not otherwise specified.”

    dcdIn addition to changes to the categorization, there were some minor changes to the criteria within each disorder.  DCD, also commonly known as dyspraxia, has the fewest of the changes.  In the DSM-IV-TR, developmental coordination disorder was diagnosed if a child’s behavior met the certain criteria: a) the child had to have significantly lower motor coordination skills than his/her chronological age; b) this had to be interfering with the child’s life; c) the lack of motor coordination skills could not be attributed to another medical condition and the diagnosis could not meet the criteria for Pervasive Developmental Disorder (PDD); and d) if the child presented with mental retardation, then the motor problems had to be excessive for MR alone.   Now the term “mental retardation” is no longer being used (according to the DSM-5 the preferred label is “intellectual disability” or ID), as it possesses some rather nasty connotations (but that is neither here nor there for this discussion).  The two main differences between the DSM IV-TR criteria and the DSM-5 criteria for this disorder are: a) there is no such statement about PDD in the DSM-5 and b) the latest revision explicitly states that the disorder onsets in early childhood.  Clearly, this disorder is associated with certain other disabilities or impairments, such as ID and autism spectrum disorders, which may be why the exception for PDD was removed.  Moreover, the statement that the disorder begins in early childhood could be due to the nomenclature emendation of the general class to which motor disorders belongs.

    Stereotypic movement disorder (SMD) shares a revision to the criteria with DCD, such that, the DSM V states that it begins in early childhood.  SMD is a repetitive, seemingly purposeless motor behavior, which may involve self-harm and interference with various aspects of the individual’s life (e.g. school, work, social, etc.)  The other major differences for SMD criteria is that the DSM IV-TR stated that the behaviors had to persist for four (4) weeks at a minimum before a diagnosis could be assigned, assuming all the other criteria were met, of course.  Also, there are now specifications for the criteria in the DSM-5, which assess severity, self-injury, and other factors, such as medical or environmental conditions.  This disorder too is highly associated with other disorders like ID and ASD’s and can be a meaningful indication of a serious underlying condition that has yet to be diagnosed or possibly even manifest.  However, beyond being a potential indication of underlying problems, it does seem arbitrary to have the specification for self-injury.  The DSM IV-TR stated in the criteria that the individual needed to be hurting himself or herself (or potentially so, in that, if preventive methods weren’t applied, the individual would be self-harming) or for there to be disturbances in school, work, play, etc.  The DSM IV-TR also stated that the individual had to have caused enough harm to seek medical attention.  This seems to conceivably excluded those who may have hurt themselves but not “required” medical attention, which could be problematic for several reasons, one of which could be lack of access to proper medical care or the child’s caretakers views being such that they do not seek care for these types of quandaries.

    ticsUnlike the other two disorders, there were minimal “structural” changes to the tic disorders criteria, save for the fact that the whole section was moved under the motor disorders instead of being their own category.  Tics are involuntary, sudden, and repetitive muscle contractions, which may result in observable movements or audible vocal expression. The tic disorders is a subcategory of disorders and were hierarchal in nature, remaining so with the new revisions.  The subcategory contains Other Specified and Unspecified Tic Disorder, Provisional Tic Disorder, Persistent Motor or Vocal Tic Disorder, and Tourette’s Disorder.  The biggest change to this category is that the DSM IV-TR required the sufferer to not have a period of more than three (3) months tic-free.  The DSM-5 does not have this requirement in the criteria.  This difference is most likely an improvement, in that, the tics may “wax and wane” according to the DSM.  This older criteria would have excluded someone from diagnosis or redacted a diagnosis (perhaps) if the tics were in a waning period more than three (3) months, but not extinct.  Further, the criteria for tic disorders according to both versions of the DSM stated that the individual had to be under the age of 18 when the tics manifested, with the exception of Other Specified Tic Disorder and Unspecified Tic Disorder.  This is a marked difference between the Tic Disorders and the other two disorders.  One final (relatively small) divergence is Transient Tic Disorder was renamed to Provisional Tic Disorder.

    It is important to remember that culture plays a critical role in the diagnosis and treatment of any psychological disorder, but particularly with motor disorders, as the individuals being diagnosed and treated are not the ones seeking diagnosis and treatment.  They are minors and are subject to the limitations of their caregivers.  This could still be so for those who are adults and severely ID, which again is heavily associated with the motor disorders.  For the vast majority of individuals who are diagnosed with these disorders, they will “grow out of it,” but not everyone does.  Treatment is still necessary and will help these individuals cope with their challenges.

    Category: Mental HealthPsychologyScienceTeaching


    Article by: Caleb Lack

    Caleb Lack is the author of "Great Plains Skeptic" on SIN, as well as a clinical psychologist, professor, and researcher. His website contains many more exciting details, visit it at www.caleblack.com