It is easy to become confused about the relationship between misophonia and anxiety. People often wonder if misophonia causes anxiety. And, people wonder if anxiety causes misophonia, or makes it worse! Whether you suffer from misophonia or have a loved one with the disorder (or are a clinician) thinking about the differences and similarities between anxiety and misophonia may be very helpful.
Preliminary research demonstrates that misophonia and anxiety are two separate disorders. However, the two conditions certainly interact (Cavanna & Seri, 2015). Both misophonia and anxiety tap into the same neurophysiological systems. That is, when one feels anxious the part of the brain that readies a person for flight/flight is activated (Ledoux, 2015). This is the same for misophonia!
When we feel anxious or when we react aversively to a misophonic trigger, we feel the effects of the nervous system being aroused. For example, one may feel their heart beating fast, their palms becoming sweaty and so on (Rouw & Erfanian, 2017). In both misophonia and with anxiety, as we experience this neurophysiological reaction, we simultaneously form thoughts about what is happening to us. However, there is an essential difference between misophonia and anxiety!
For the most part, misophonia begins with an external stimulus (usually a sound, and sometimes a visual cue). In misophonia if the sound or visual was not present, one would not react to it!  This is different from anxiety. With anxiety, an internal stimulus may bring about nervous system activation. Now, this is not “perfect science”. For some people with misophonia, just thinking about a trigger might cause reactivity. However, as a general rule, this is a good way to start understanding how anxiety and misophonia are similar and different.
For many people with misophonia, the aversive reactivity goes away as soon as the sound is no longer present, or at least one feels the responsivity abating in the absence of the auditory (or visual) stimuli. For example, if one is triggered and leaves the dinner table the nervous system calms very quickly, or at least soon after. This is because the misophonia trigger is coming from the outside world, it is for the most part, external.
Anxiety on the other hand, can be activated simply because a person is thinking about something they are concerned about. For example, one might feel anxious about a job interview or a school assignment that is due the next day, or one may evaluate the potential consequences of something from their past. For example, an individual may think, “I am very worried about how I did on my final exam”. Here, the internal stimuli (the thought) cause the reaction. In addition, anxiety may be long lasting because we can continue to think about that which we are worried about for quite some time. Again, this is not “perfect science” and is somewhat simplistic, but it helps to remember this:
Anxiety is often brought about by things we may think about or worry about. This is internal.
Sounds or sights bring about Misophonia as they enter our system through the outside world (external stimuli).
Of course this doesn’t mean that anxiety (or anxious feelings) doesn’t make the misophonic response worse. If one is anxious because they are thinking about something provocative, the nervous system is already on alert. The person is already “revved up”. Then, when the misophonic trigger occurs one will escalate more quickly and with more intensity. Similarly, an anxious person may react with more intensity to auditory or visual stimuli from the outside world.
Unfortunately, many of us also worry (or become anxious) about misophonia, and/ or about entering a place where we know triggers are present. This is anticipatory anxiety/
What can one do about this?
I always say that the first step to coping with misophonia is understanding what it is. Once an individual has a basic understanding of how sounds affect their nervous system, one may begin to feel a little less overwhelmed. Understanding your own responses to triggers is certainly not a “miracle cure”. However, we tend to be less overwhelmed by what we understand.
Once you have differentiated misophonia reactivity from anxiety it helps to clarify what you are experiencing with regard to both. Although, this may not significantly change the automatic nervous system response, "unpacking" your own experiences is a definitive step toward coping with the disorder.
 While most people with misophonia report that they feel much calmer when stimuli is removed, there are some for whom the stimuli persists in memory. This is true of both visual and auditory stimuli.
For more information about misophonia http://www.misophoniainternational.com and
Cavanna, A.E. and Neal, M. (January 2013). Selective Sound Sensitivity Syndrome (Misophonia) in a Patient with Tourette Syndrome. The Journal of Neuropsychiatry and Clinical Neurosciences. Vol. 25 (1). doi:10.1176/appi.neuropsych.11100235.
Ledoux, J.E. (2015). Anxious.: Using the Brain to Understand and Treat Anxiety. Penguin Press New York.
Rouw, R and Erfanian, M. (May 2017). A Large-Scale Study of Misophonia. Journal of Clinical Psychology. DOI: 10.1002/jclp.22500