Misophonia: Personality Quirk, Symptom, or Neurological Disorder?

When I first learned about misophonia, it was described as a severe annoyance by certain specific sounds, most commonly bodily sounds such as chewing, breathing and slurping, or repetitive sounds such as ceiling fans, beeping, etc.  A quick Wikipedia search described it as, “a form of decreased sound tolerance… believed to be a neurological disorder characterized by negative experiences resulting only from specific sounds, whether loud or soft.”

Immediately, I had a number of questions: if misophonia is just a hatred of certain sounds that leads to annoyance or anger, how is this classified as a neurological disorder?  Wouldn’t everyone have this disorder to some degree?  Everyone has their pet peeves as far as sound goes; I cannot stand the sound of people chewing, and while it is sometimes very irritating, I would by no means say that I have a neurological disorder.

The Wikipedia entry stated, “Intense anxiety and avoidant behavior may develop, which can lead to decreased socialization. Some people may feel the compulsion to mimic what they hear.”  If everyone has sounds that they hate, but some people get uncontrollably angry or anxious when they hear their hated sounds, then isn’t this disorder a behavioral issue?  I initially had two hypotheses about misophonia: 1) someone who cannot control their behavior in response to certain sounds probably has trouble controlling their behavior in response to other stimuli as well, and therefore misophonia is the side-effect of another neurological or psychiatric disease, not its own one.  And 2) misophonia is one of those “disorders” that just seems like a scheme to sell more drugs to hypochondriacs.  But this was Wikipedia, so I first looked to the DSM-IV to learn more about misophonia.

Misophonia is not classified in the DSM-IV, so even in the small pool of research available on the subject, there seems to be little agreement on what misophonia actually is and what causes it.  Some papers lump misophonia into the same category as tinnitus (hearing ringing sounds that are not there, usually due to cochlear damage or hearing loss) and hyperacusis (sensitivity to sound).  In a study of tinnitus patients, Sztuka et al [7] found that 10% of the patients they studied had misophonia.  However, other studies found that while hyperacusis, tinnitus, and misophonia are related, misophonia is not caused by auditory damage. Jastreboff and Jastreboff [3, 4], found that when a trigger sound is played to people with misophonia, it results in a larger activation of the limbic and autonomous nervous system, but not a larger activation of the auditory system.  The limbic system plays a part in other behavioral disorders such as OCD, so this suggests that misophonia could have an anatomical origin that may cause people with misophonia to react to sound differently.  Now that I had learned of an actual neurological difference in people with misophonia, I felt that my initial reaction - that misophonia is a ridiculous attempt to label something normal as a disorder - was false.  However, there is still evidence to support the position that misophonia is a symptom of a larger behavioral disorder, so I wondering about the legitimacy of misophonia as a stand-alone behavioral disorder.

A map of the misophonia activation pathway, from Tinnitus Retraining Therapy: Implementing the Neurophysiological Model [4]

Another study published in January of this year studied 42 patients with misophonia. [5]  The triggers for these patients were all human-generated noises; chewing, breathing, hand sounds, etc.  Some patients also reported visual triggers, simply referred to as “repetitive visual movements.”  This study conducted several personality tests and found that of their 42 patients, 35 had a comorbid disorder including mood disorders, panic disorders, ADHD, OCD, and OCPD, among others.  22 out of 42 patients were found to have Obsessive-Compulsive Personality Disorder (OCPD), a disorder characterized by “a chronic non-adaptive pattern of extreme perfectionism, preoccupation with neatness and detail, and a requirement or need for control or power over one’s environment.”  Since OCPD is estimated to occur in 7.88% the population [1], the extremely high comorbidity of misophonia and OCPD found in this study cannot be ignored.  Interestingly, in the discussion of this paper, Schröder et al. call to distinguish misophonia its own neurological disorder, explaining how misophonia is not a symptom of another disorder, but its own disorder [5].  They assert that misophonia, while similar to social phobia, is not a social phobia because patients do not feel anxiety, only anger and disgust.  Other studies [3, 4, 6]  found that misophonia patients do feel anxiety or fear as well as anger.  This paper also says that misophonia cannot be caused by OCD, because while they are both marked by obsession and avoidance, misophonia patients do not perform compulsions.  However, Hadjipavlou et al. found that misophonia patients will often mimic compulsively annoying sounds as a way to reduce the stress caused by them.

But to me it still remains unclear whether misophonia is a separate, distinct disorder.  Since misophonia is reported in people with auditory disorders as well as people with behavioral and mood disorders, it seems as though misophonia is a symptom, not its own disorder.  However, this begs the question, “How do we define a disorder?”  Many disorders are co-morbid with each other, yet we still classify them separately and we especially have difficulty with psychiatric disorders. These topics have also been discussed on this blog here, here, and here.

Right now, it seems that there are not many good treatment options for people suffering from misophonia.  Certain therapies including Cognitive Behavioral Therapy, and Tinnitus Retraining Therapy are options- while these options may improve symptoms, they are not a cure for the disorder.  In fact, in this blog submission, the patient’s therapist had not even heard of misophonia.  At this point it seems that whether it actually is its own disorder or caused by something else is less relevant than the problem that those suffering from the disorder are not getting the treatment they need.   However, it seems that providing misophonia with its own distinct identity might be part of the solution for helping these patients.  Hopefully the call to recognize misophonia as a disorder will spark interest in the subject, which will increase research on the neurological mechanisms of misophonia and innovation in treatment, so that patients will eventually be able to receive the treatment they need.

References
[1] Grant, Bridget F., et al., "Prevalence, Correlates, and Disability of Personality Disorders in the United States: Results From the National Epidemiologic Survey on Alcohol and Related Conditions." The Journal of Clinical Psychology 65 (2004): 948-58. Print.

[2] Hadjipavlou, G., S. Baer, A. Lau, and A. Howard. "Selective Sound Intolerance And Emotional Distress: What Every Clinician Should Hear." Psychosomatic Medicine70.6 (2008): 739-40. Print.

[3] Jastreboff, Margaret M. "Chapter 2: Decreased Sound Tolerance." Tinnitus: Theory and Management. By Pawel J. Jastreboff. Hamilton, Ont.: BC Decker, 2004. 8-15. Print.

[4] Jastreboff, Pawel J., and Jonathan J.P. Hazell. Figure 2.14. N.d. Tinnitus Retraining Therapy: Implementing the Neurophysiological Model. N.p.: Cambridge UP, 2004. 49. Print.

[5] Schröder, Arjan, Nienke Vulink, and Damiaan Denys. "Misophonia: Diagnostic Criteria for a New Psychiatric Disorder." PLoS One 8.1 (2013): n. pag. 23 Jan. 2013. Web.

[6] Schwartz, Paula, Jason Leyendecker, and Megan Conlon. "Hyperacusis and Misophonia The Lesser-Known Siblings of Tinnitus." Minnesota Medicine (2011): 42-43. Print.

[7] Sztuka, Aleksandra, Lucyna Pospiech, Wojciech Gawron, and Krzysztof Dudek. "DPOAE in Estimation of the Function of the Cochlea in Tinnitus Patients with Normal Hearing."Auris Nasus Larynx (2009): n. pag. Print.


About the author 
Emily Young is a third-year undergraduate Biology major at Georgia Tech.  She has participated in research at the Center for Advanced Brain Imaging at Georgia Tech, BRAIN, the United States Army Criminal Investigations Laboratory, and currently works in Dr. Maney’s lab at Emory University.  Emily is also the Vice President of marketing of GTNeuro, the neuroscience club at Georgia Tech.

Want to cite this post?
Young, E. (2013). Misophonia: Personality Quirk, Symptom, or Neurological Disorder? The Neuroethics Blog. Retrieved on , from http://www.theneuroethicsblog.com/2013/04/misophonia-personality-quirk-symptom-or.html

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