Misophonia shares genetics with depression, anxiety and PTSD

A recent study published in Frontiers in Neuroscience shed light on the genetics associated with misophonia, a condition in which certain sounds—such as chewing or breathing—evoke strong emotions such as anger, anxiety or disgust. Researchers have found that misophonia shares genetic significance with psychological disorders, particularly anxiety and post-traumatic stress disorder (PTSD).

Misophonia, although increasingly recognized, is still poorly understood in terms of its causes and mechanisms. The condition is often described as a mental disorder or a broad medical disorder, but agreement on its classification has been difficult.

Although misophonia can be very disruptive to daily life, prompting some people to seek professional help, the biological and genetic basis of the disorder has not been fully explored. The researchers aimed to fill this knowledge gap by investigating the genetic origins of misophonia.

“As a researcher, when you explain what you’re working with – misophonia in this case – some get confused. But I was very surprised to hear that many would say, ‘Oh, I know someone who has that,’ or they say, ‘Oh, but I am,'” said study author Dirk JA Smit, associate professor of psychology and genetics at the University of Amsterdam Medical Center.

And they weren’t laughing—they admitted it was a real life-threatening problem. In some cases, this leads to families not eating together, or people avoiding co-workers at lunch, after drinking at work, or at other social events. Many didn’t even know the word ‘misophonia,’ so it’s something that’s underreported.”

To do this research, scientists used a genetic analysis method known as Genome-Wide Association Study (GWAS). GWAS examines the genes of a large group of people to find genetic variants associated with certain traits or disorders. In this case, the researchers analyzed the genetic information related to a symptom like misophonia: feeling strong anger caused by the sound of chewing. The researchers used data from a variety of sources, including 23andMe, UK Biobank, and the Psychiatric Genomics Consortium.

The sample included 80,607 people who self-reported whether or not they had experienced this anger response. Although this representative does not cover all aspects of misophonia, it provides an important starting point for genetic testing.

In addition to examining the genetic factors associated with this symptom of misophonia, the researchers also examined genetic relationships between this symptom and 44 other characteristics or problems. The research team divided the 44 traits into several groups: mental illnesses (such as depression and anxiety), hearing conditions (such as tinnitus), personality traits (such as neuroticism), and other factors such as achieving education.

Genetic testing has confirmed that misophonia has a genetic basis. A specific gene region (rs2937573) was identified to be strongly associated with feeling strong anger caused by the sound of chewing. This region is close to the TENM2 gene, which is involved in brain development and cell adhesion. Although the specific role of this gene in hearing or sensitivity to sounds is not yet fully understood, it is a promising area for future research.

One of the key findings was the strong genetic link between misophonia and mental illness, particularly anxiety and post-traumatic stress disorder. Misophonia has shown significant genetic association with major depressive disorder. These findings suggest that misophonia may share genetic factors with these psychological conditions, supporting the idea that misophonia can be classified as a mental illness.

In terms of personality traits, the study found that people with misophonia genes were also more likely to have traits such as neuroticism, guilt, irritability and anxiety. These characteristics are often associated with internalizing emotional reactions, which is consistent with previous theories that people with misophonia tend to internalize their suffering rather than express it externally.

“Most of the results are not surprising,” Smit told PsyPost. “Misophonia in its most common form provokes anger at the sounds of eating, although there are many different emotions and sound combinations. In line with this, we found that the genetics of misophonia are related to the genetics of the personality trait ‘irritability,’ which is the meaning of misophonia: you get irritated and angry when you hear a trigger sound, which can be traced are avoidance behaviors, feelings of guilt, and more. ”

“There has been genetic association with PTSD. This means that genes that confer susceptibility to PTSD also increase the likelihood of misophonia, and that may point to a shared neurobiological system that affects both. And that would suggest that the same treatment methods used for PTSD could also be used for misophonia.”

Interestingly, the study also found a moderate genetic link between misophonia and tinnitus, a condition characterized by persistent ringing or ringing in the ears. This suggests that while misophonia may not be directly related to hearing loss or poor sound processing, they may share some cognitive or neurological mechanisms.

“There was also an association with the risk of tinnitus,” Smit explained. “What makes this connection is not clear, but tinnitus almost always has a clear cause of hearing loss of some kind, which may be caused by exposure to loud music, ototoxic medications, infections, or aging. But psychological factors are also known to play a role in the condition, so this may be the link.”

However, no significant correlations were found between misophonia and other sensory characteristics, such as hearing or hearing loss, supporting the view that misophonia is closely related to psychological factors. than hearing problems.

Perhaps the most unexpected result of the study was the negative genetic link between misophonia and autism spectrum disorder. This means that individuals genetically predisposed to misophonia are less likely to have genes associated with autism. This result contrasts with earlier clinical observations that suggested some overlap between the two conditions. “There was a small but negative correlation between misophonia genetics and autism genetics,” Smit said. “Given that autism is often associated with hearing problems, that was unexpected. I expected a positive correlation.”

This study provides important information about the genes that cause misophonia and its genetic approach allows to clearly identify the basic biological pathways, reducing the risk of negative correlations caused by different factors that can advantages such as culture or economic conditions. In addition, by using data from major sources such as UK Biobank and 23andMe, the researchers were able to obtain a large amount of genetic information. This scale is very useful because it allows the assessment of many traits and problems at the same time.

But as with all research, there are some limitations to consider. One of the biggest obstacles is that research has focused on genetics in the general population rather than people diagnosed with misophonia. Although the use of genetic information provides insight into predispositions and risks, it does not directly diagnose disease in diagnosed individuals.

“Our study was based on the 23andMe model, where participants answered a few simple questions about misophonia and the taste of cilantro,” Smit explained. “Although this led to very interesting results, it did not include a validated questionnaire or a clinical evaluation through structured interviews. So the results will be somewhat affected by reporting bias.”

It is also important to note that genetic correlations reflect shared genetic risk factors but do not necessarily indicate direct causal relationships between traits. Therefore, although the study found significant associations between misophonia and conditions such as anxiety and post-traumatic stress disorder, it cannot definitively determine whether these disorders share common pathways. the same cause or whether they meet only for other genetic risk factors.

Looking ahead, the researchers suggest that future studies should investigate whether different emotional responses to misophonia-induced sounds (such as anxiety or fear rather than anger) are associated and different genetic profiles. This can help to clarify whether misophonia is the same disorder or if there are different types depending on the basic perception of sound production.

In addition to examining possible subtypes, the team also focused on how misophonia occurs in certain populations, such as people with autism.

“We continue with the report of misophonia in autism, a phenomenon that has not been studied in this group, although they have studied other auditory symptoms such as hyperacusis and phonophobia; hearing loss is a well-known symptom in many autistic people ,” Smit explained. “This study on the prevalence of misophonia in autism is important because many people with autism show symptoms of misophonia, but other treatments, such as cognitive-behavioral therapy, may it does not suit them.”

The study, “A genome-wide association study of anger-related misophonia symptoms and genetic associations with sensory, psychiatric and personality traits,” was written by Dirk JA Smit, Melissa Bakker, Abdel Abdellaoui, Alexander E. Hoetink, Nienke Vulink, and Damiaan Denys.