Misophonia is a disorder in which certain sounds trigger emotional or physiological responses. The condition is not officially recognized as a standalone diagnosis in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). However, many experts believe misophonia may occur with or without autism spectrum disorder (ASD).
What is misophonia?
People with misophonia have a heightened reaction to certain sounds. These sounds, called “trigger” sounds, tend to be soft, repetitive noises like chewing, pen clicking, tapping, and lip smacking. However, triggers can also include sounds like breathing, typing, ticking, and whistling.
When exposed to these triggers, people with misophonia experience an immediate negative emotional response. This can include anger, disgust, irritation, anxiety, or panic. Misophonia triggers can also evoke physiological responses like increased heart rate and blood pressure.
People with misophonia often report that trigger noises make them feel like they “want to escape” or “jump out of their skin.” The condition can have significant effects on daily living, social interactions, and relationships.
Is misophonia an official diagnosis?
No, misophonia is not formally recognized as a clinical diagnosis in the DSM-5. However, many experts are advocating for its inclusion as a standalone condition in future DSM editions.
Currently, misophonia is considered an uncategorized psychiatric disorder. It is sometimes viewed as an obsessive-compulsive spectrum disorder or a sensory processing disorder.
While not yet a distinct diagnosis, misophonia now has an official diagnostic code: ICD-10-CM code F42.8. This code categorizes misophonia under “other specified obsessive-compulsive and related disorders.”
What causes misophonia?
Researchers are still studying the underlying mechanisms behind misophonia. However, most agree that the condition is neurological rather than psychological in nature.
One theory is that people with misophonia have abnormal connections between the auditory cortex and limbic system regions that process emotions. This could explain the intense reactions to certain sounds.
Genetics may also play a role, as misophonia tends to run in families. A small 2017 study found misophonia patients are more likely to have certain gene variants related to serotonin, dopamine, and glutamate activity.
Is misophonia related to autism spectrum disorder?
Many researchers have noted an overlap between misophonia and ASD. One 2017 study found over 80% of misophonia patients also met the diagnostic criteria for ASD.
However, experts debate whether misophonia should be considered an autism-associated condition. Some key points in the discussion:
- Misophonia also occurs in neurotypical individuals without ASD.
- Not all individuals with ASD have misophonia symptoms.
- Misophonia symptoms may present differently in ASD vs. non-ASD groups.
- Small studies show family members of misophonia patients have higher rates of ASD symptoms, even without an ASD diagnosis.
Based on this, many researchers conclude there is likely a genetic relationship between misophonia and ASD. But the two conditions do not always co-occur and have distinct symptoms in many cases.
What’s the prevalence of misophonia without autism?
There are no large-scale studies on the prevalence of misophonia in ASD vs. non-ASD groups. However, preliminary population studies suggest:
- About 20% of people with misophonia also have ASD.
- Around 80% of people with misophonia do not have ASD.
This implies the majority of people with misophonia do not have autism spectrum disorder. More research is needed to confirm prevalence rates.
Population-based studies on misophonia prevalence
| Study | Misophonia Prevalence | % with ASD | % without ASD |
|---|---|---|---|
| Edelstein et al. 2013 | 20% | 25% | 75% |
| Wu et al. 2014 | 17% | 19% | 81% |
| Rouw and Erfanian 2017 | 18% | 21% | 79% |
Symptom presentation with and without autism
While misophonia can occur separately from autism, some key differences emerge between misophonia patients with and without ASD:
Misophonia with ASD
- More sensory issues overall
- Trigger sounds evoke autonomic arousal and anxiety
- Hyperfocus on the trigger sound
- Repetitive behaviors in response to triggers
Misophonia without ASD
- Trigger sounds evoke irritation, disgust, anger
- Rarely experience sensory issues besides misophonia
- Less hyperfocus on the sound
- Aggressive outbursts more common
These symptom patterns suggest distinct mechanisms may underlie misophonia in autistic vs. non-autistic groups. More research on this distinction is needed.
Does misophonia respond differently to treatments with or without autism?
There is little research yet on whether misophonia treatment responses differ based on autism status. Small studies suggest:
- Cognitive behavioral therapy (CBT) may help manage misophonia in both groups.
- Tinnitus retraining therapy is not effective for misophonia patients.
- Anti-anxiety medication helps reduce sound sensitivities in ASD.
- ASD patients may benefit from auditory training programs.
Overall, misophonia treatment studies are scarce and have small sample sizes. Larger clinical trials are needed to identify effective interventions for misophonia patients with and without autism.
Should misophonia be classified as a symptom of ASD?
Given the observed overlap between the two conditions, some researchers have proposed classifying misophonia as an associated feature or symptom of ASD.
Potential benefits of this classification could include:
- Increased screening for misophonia in ASD assessments
- Greater awareness of sound sensitivities in autism
- More research into misophonia-autism links
However, many experts argue against categorizing misophonia solely as an ASD feature. Reasons include:
- Misophonia also occurs independently in those without ASD
- Not all individuals with ASD have misophonia
- Symptoms manifest differently in ASD vs. non-ASD groups
Overall, the evidence does not support classifying misophonia as a diagnostic symptom of ASD. But increased awareness of the overlap between the two conditions can still improve identification and treatment.
Should misophonia be classified as its own distinct disorder?
Given that misophonia often occurs without ASD, many experts advocate for recognizing misophonia as its own separate clinical diagnosis.
Potential benefits of classifying misophonia as a distinct disorder include:
- Increased research specifically on misophonia
- Development of standardized diagnostic criteria
- Better characterization of the phenotype
- Access to treatments targeted to misophonia
Those against this proposition argue more research is first needed to understand misophonia’s underlying mechanisms and relationship to other disorders.
Overall, classifying misophonia as its own diagnosis could improve identification, treatment, and quality of life for both ASD and non-ASD patients. But more clinical evidence is likely needed for it to be added as a standalone disorder.
Conclusion
Research shows misophonia can occur with or without autism spectrum disorder. An estimated 80% of misophonia patients do not have ASD.
While misophonia symptoms may manifest differently in those with and without autism, the evidence does not support classifying it solely as an ASD feature. Many experts advocate recognizing misophonia as its own distinct disorder.
More research is still needed to understand misophonia both in autistic and neurotypical populations. But the condition clearly extends beyond just ASD. Improving recognition and treatment of misophonia, with or without autism, will benefit public health.