Misophonia

Misophonia (or selective sound sensitivity syndrome, sound-rage) is a disorder of decreased tolerance to specific sounds or their associated stimuli, or cues. These cues, known as "triggers", are experienced as unpleasant or distressing and tend to evoke strong negative emotional, physiological, and behavioral responses that are not seen in most other people. Misophonia and misophonic symptoms can adversely affect the ability to achieve life goals and enjoy social situations. It was first recognized in 2001, though it is still not in the DSM-5 or any similar manual. For this reason it has been called a "neglected disorder".

Reactions to trigger sounds range from annoyance to anger, with possible activation of the fight-or-flight response. Misophonia responses do not seem to be elicited by the loudness of the sound, but rather by its specific pattern or meaning to the hearer. Triggers are commonly repetitive stimuli and are primarily, but not exclusively, related to the human body, such as chewing, eating, smacking lips, slurping, coughing, throat clearing, sniffing, and swallowing. Once a trigger stimulus is detected, people with misophonia may have difficulty distracting themselves from the stimulus and may experience suffering, distress, and/or impairment in social, occupational, or academic functioning. The expression of misophonia symptoms varies, as does the severity, which ranges from mild to severe. Some people with misophonia are aware that their reactions to misophonic triggers are disproportionate to the circumstances. Misophonia symptoms are typically first observed in childhood or early adolescence. Studies have shown that misophonia can cause problems in school, work, social life, and family.

Origin of term
The term was coined in 2001 by professor Pawel Jastreboff and doctor Margaret M. Jastreboff, with the assistance of the classicist Guy Lee, introducing it in their article "Hyperacusis", with further explanation in the International Tinnitus and Hyperacusis Society's ITHS Newsletter.

The term "misophonia" was first used in a peer-reviewed journal in 2002. Before that, the disorder was more commonly called "Selective Sound Sensitivity Syndrome", or "4S", named by audiologist Marsha Johnson. Others have proposed "Conditioned Aversive Response Disorder" (C.A.R.D.) as a more suitable name.

"Misophonia" comes from the Ancient Greek words μῖσος (IPA: ), meaning "hate", and φωνή (IPA: ), meaning "voice" or "sound", loosely translating to "hate of sound", and was coined to differentiate the condition from other forms of decreased sound tolerance such as hyperacusis (hypersensitivity to certain frequencies and volume ranges) and phonophobia (fear of sounds).

Signs and symptoms
, the literature on misophonia was limited. Some initial small studies showed that people with misophonia generally have strong negative feelings, thoughts, and physical reactions to specific sounds, which the literature calls "trigger sounds". These sounds usually appear quiet or unnoticeable to others, but can seem loud, or at least unpleasantly magnified, to the person with misophonia. One study found that around 80% of the sounds were related to the mouth (e.g., eating, slurping, chewing or popping gum, whispering, whistling, nose sniffing) and around 60% were repetitive. But more recent research provides neural evidence for non-orofacial triggers. A visual trigger may develop related to the trigger sound, and a misophonic reaction can occur in the absence of a sound (examples include leg swinging, hair twirling, and finger pointing).

Reactions to triggers can range from mild (anxiety, discomfort, and/or disgust) to severe (rage, anger, hatred, panic, fear, and/or emotional distress). There may be unwanted sexual arousal. This latter symptom appears to have certain parallels to the corresponding subtype of obsessive-compulsive disorder  and is likewise often misunderstood and underreported for fear of misinterpretative stigma, but it is common.

Reactions to the triggers can include aggression toward the origin of the sound, leaving, remaining in its presence but suffering, trying to block it, and trying to mimic the sound. Reactions can also include physical responses, such as increased heart rate, tightness in the chest and head, and hypertension.

The first misophonic reaction may occur when a person is young, often between the ages of 9 and 13, and can originate from someone in a close relationship, or a pet.

Fear and anxiety associated with trigger sounds can cause the person to avoid important social and other interactions that may expose them to these sounds. This avoidance and other behaviors can make it harder for people with this condition to achieve their goals and enjoy interpersonal interactions. It can also have a significant negative effect on their careers and relationships.

Combined studies have illustrated that 45% of cases of misophonia became worse over time without treatment.

Mechanism
Misophonia's mechanism is not yet fully understood, but it appears that it may be caused by a dysfunction of the central nervous system in the brain and not of the ears. The perceived origin and context of the sound appears to play an important role in triggering a reaction.

A 2017 study found that the anterior insular cortex (which plays a role both in emotions like anger and in integrating outside input, such as sound, with input from organs such as the heart and lungs) causes more activity in other parts of the brain in response to triggers, particularly in the parts responsible for long-term memories, fear, and other emotions. It also found that people with misophonia have higher amounts of myelin (a fatty substance that wraps around nerve cells in the brain to provide electrical insulation). It is not clear whether myelin is a cause or an effect of misophonia and its triggering of other brain areas.

A 2021 study found that the orofacial motor cortex, a part of the brain representing lip, jaw, and mouth movement, has enhanced activation for typical trigger sounds much more than for aversive or neutral sounds in misophonia sufferers. It also found enhanced functional connectivity between orofacial motor cortex and secondary auditory cortex during sound perception for any sound. It further reported resting state fMRI functional connectivity between orofacial motor cortex and secondary auditory and visual brain areas as well as secondary interoceptive cortex (left anterior insula). This suggests that misophonia, which is typically thought of as a disorder of sound emotion processing, is a result of overactivation of the motor mirror neuron system involved in producing the movements associated with these trigger sounds or images.

Diagnosis
In 2022, clinical and scientific leaders convened to create a consensus definition of misophonia, agreeing that it is a disorder of decreased tolerance to specific sounds and their associated stimuli. Before this consensus definition was reached, scholars and clinicians debated how to describe and define misophonia, which has limited comparison of study cohorts and hampered the development of standard diagnostic criteria.

Misophonia is distinguished from hyperacusis, which is not specific to a given sound and does not involve a similar strong reaction, and from phonophobia, which is a fear of loud sounds, but it may occur with either. There are no standard diagnostic criteria, and many doctors are unaware of the disorder.

Studies show that misophonia often has related comorbid conditions, including anxiety disorders, post-traumatic stress disorder, OCD,  and depressive disorders. Some research supports the belief that misophonia is genetic, but more research is needed. It appears that misophonia can occur on its own or along with other health, developmental, and psychiatric problems. When attempting to diagnose a patient with misophonia, doctors sometimes mistake its symptoms for an anxiety disorder, bipolar disorder, or obsessive-compulsive disorder.

Despite misophonia's relative phenotypic distinctiveness, it has been suggested that it belongs to the spectrum of obsessive-compulsive-and-related disorders. Indeed, distinguishing certain elements of misophonia from those of obsessive-compulsive disorder and obsessive-compulsive personality disorder may be difficult, as many features often overlap.

Classification
The diagnosis of misophonia is not recognized in the DSM-IV or the ICD-11, and it is not classified as a hearing or psychiatric disorder. It may be a form of sound–emotion synesthesia, and has parallels with some anxiety disorders. A 2022 structured study of prominent researchers resulted in the creation of the consensus definition of misophonia, determining that misophonia should be classified as a disorder, and not a symptom of another condition or syndrome. During the early phase of research on misophonia, it was defined by different criteria with variable methods used to diagnose and assess symptom severity. As a result of lack of consensus about how to define and evaluate misophonia, comparisons between study cohorts were difficult, measurement tools were not psychometrically well-validated, and the field could not rigorously assess the efficacy of different treatment approaches. The creation of the definition serves as the foundation of future diagnostic criteria and validated diagnostic tools, and brings cohesion to the diverse and interdisciplinary misophonia research and clinical communities.

Management
Health care providers generally try to help people cope with misophonia by recognizing what the person is experiencing and working on coping strategies. A majority of smaller studies done on the subject have focused on the use of tinnitus retraining therapy, cognitive behavioral therapy and exposure therapy, which is believed to decrease the person's awareness of their trigger sounds. These treatment approaches have not been sufficiently studied to determine their effectiveness. Other possible treatment options have been theorized by researchers, including acceptance-based approaches and mindfulness. Ultimately, it is speculated that treatment methods may vary significantly in effectiveness from patient to patient.

Minimal research has been conducted on the possible effects of neuromodulation and pharmacologic treatments. A study published in 2022 suggests that some forms of misophonia treatment may vary in effectiveness based on the preference of each patient, particularly in cases of parents with children who have misophonia. In addition, the use of propranolol has also been found to be helpful in some patients.

Clomipramine has anecdotally been found to be of use in at least a certain subset of people suffering from disorders allied with hyperacusis; given its success in the treatment of obsessive-compulsive disorder, it may have a place in the treatment of misophonia, which appears to have parallels with both conditions. Clomipramine does appear to have a distinct potential mediating effect on auditory-tone processing. One specific phenomenon observed to this end with clomipramine in at least one instance is reduced electrodermal reactivity to innocuous auditory stimuli.

Whether pindolol (a beta-blocker with similar action to propranolol and augmentative therapeutic effects in obsessive-compulsive disorder ) and certain selective serotonin reuptake inhibitors (e.g., fluvoxamine, escitalopram, fluoxetine) can also prove effective in the treatment of misophonia likewise remains to be seen.

Large-scale research has not yet been conducted, but observation of coping strategies people with misophonia use has shown some consistent results. People with misophonia often cope by avoiding distressing situations and/or distracting themselves from such situations, for example by using earplugs or headphones, mimicking trigger sounds, and playing music.

Epidemiology
Research is still being conducted on misophonia's global prevalence, but a 2023 study found its prevalence in the UK to be around 18%. This study has been cited in popular outlets, including BBC, Medscape, and Medical Xpress. Studies of misophonia's global prevalence have found it to be as low as 5% and as high as 20%. Its prevalence and severity seem to be similar across genders. In the U.S., it is estimated that 3% of people are affected by misophonia. But in multiple studies, it was determined misophonia may be underdiagnosed (it is not yet an officially diagnosable condition), as it is correlated with other auditory disruptions; 92% of patients who are hyperaware of sounds also have misophonia.  There is evidence that significant numbers of undergraduate students in some psychology and medical-science departments suffer from misophonia. The University of Nottingham conducted a study of misophonia in one sample of undergraduate medical students. In 2017, similar rates were found in one university in China, suggesting that the disorder is not specific to a culture.

It may be the case that people with misophonia are more likely to have high fluid intelligence.

Associated symptoms
Some people have sought to relate misophonia to autonomous sensory meridian response, or auto-sensory meridian response (ASMR), a pleasant form of paresthesia, a tingling sensation that typically begins on the scalp and moves down the back of the neck and upper spine. ASMR is described as the opposite of what can be observed in reactions to specific audio stimuli in misophonia. There are plentiful anecdotal reports of people who claim to have both misophonia and ASMR. Common to these reports is the experience of ASMR in response to some sounds and misophonia in response to others.

Society and culture
People who experience misophonia have formed online support groups.

In 2016, a documentary about the condition, Quiet Please, was released.

In 2020, a team of misophonia researchers received the Ig Nobel Prize in medicine "for diagnosing a long-unrecognized medical condition".

The 2022 film Tár depicts a conductor with misophonia.

Season 1, episode 4 of Hulu's The Old Man has a brief discussion of misophonia.

Notable cases

 * Richard E. Grant
 * Barron H. Lerner
 * Melanie Lynskey
 * Laila McQueen
 * Kelly Osbourne
 * Kelly Ripa
 * Sarah Silverman
 * Lisa Loeb