Introduction
Misophonia is a disorder characterized by over-responsivity to certain repetitive stimuli, particularly sounds, which are often produced by humans, including chewing, breathing, humming, and sniffling [
1]. These sounds, referred to as triggers, elicit feelings of irritation, anger, and sometimes disgust, anxiety, sadness, helplessness, or other emotions. Individuals with misophonia tend to avoid exposure to their triggers, and when avoidance is not possible, they experience intense distress [
2,
3]. At the same time, there is currently no data to support the notion that habituation to these sounds is possible, as is the case in anxiety disorders. As a result, their quality of life can deteriorate and social functioning may become severely impaired. While misophonia has been observed to co-occur with various psychiatric disorders [
3‐
8] or developmental disorders [
9,
10] it cannot be attributed exclusively to any specific disorder.
Since misophonia usually develops during childhood or adolescence [
11,
12], it is crucial to investigate the condition in this population to gain a more profound understanding of its development and progression and plan effective therapeutic and supportive interventions. However, there is currently limited knowledge on misophonia in youths, as almost all the research on this topic has been conducted on adults. Most of the knowledge on misophonia in children comes from several case studies, mostly reporting on patients referred to clinics [
13‐
16]. The data indicates a great variability in the co-occurrence of psychiatric disorders in this group, and highlights the idiosyncratic nature of the problem, often discussed in terms of family and school. Nonetheless, it reveals a unique pattern of misophonia symptoms in children that is observable in adults as well.
In a recent study by [
17,
18], 15 children with misophonia were identified from a sample of 142 children, and the findings showed that children with this disorder had a significantly lower quality of life compared to the overall population sample. Although the study had limitations, such as being questionnaire-based and conducted online, it provides a basis and reason for further exploration of this group. To date, only one study has investigated misophonia in a sample of children, and their parents using a combination of psychiatric face-to-face assessments and multiple questionnaires [
6]. The findings of this study align with some previous research [
7,
8] conducted on adult populations with misophonia, and reveals a high incidence of comorbid psychiatric disorders in children with misophonia. In Guzick et al.’s [
6] study, 78% of children diagnosed with misophonia met the criteria for at least one psychiatric disorder, with depression and anxiety disorders being the most commonly observed. However, the findings regarding psychiatric comorbidities in misophonia are inconsistent across studies, especially regarding attention-deficit/hyperactivity disorder (ADHD). While some studies have reported higher rates, such as Guzick et al. [
6] finding 21% of children with misophonia also had ADHD, or Kılıç et al. [
19] reporting 20% of adult misophonia sufferers with ADHD, others have reported much lower rates. For example, only 5% of adult misophonia sufferers in the Netherlands were diagnosed with ADHD [
3,
20,
21]. Conversely, Rosenthal et al. [
7] found no relationship between ADHD and misophonia symptoms in an American sample. Due to the limited data and inconsistent findings on psychiatric comorbidities in misophonia, especially in children, our study aimed to investigate these factors in a sample of Polish-speaking children and teenagers.
Although 8–11% of the children in Guzick et al.'s [
6] study exhibited clinically elevated symptoms of autism spectrum disorder (ASD), the average symptoms of ASD were not elevated in this group, and they were not found to be correlated with misophonia symptoms. In fact, the symptoms of ASD were significantly lower in children with misophonia compared to those with anxiety disorders. However, these findings are inconsistent with the data obtained by [
17,
18], who reported higher symptoms of ASD in children with misophonia. Therefore, the relationship between misophonia and ASD in the pediatric population remains unclear and requires further investigation. To address the limitations, this study aimed to examine the understanding of social functioning and emotional regulation in children with misophonia. To achieve this, in this study not only we measured ASD symptoms using parent-reporting scales, but also, we used performance-based tests to assess the social and emotional competencies of both children with misophonia and control group without misophonia. To the best of our knowledge, no previous studies have used psychological performance-based tests (in contrast to questionnaires) to evaluate these factors in children with misophonia. Moreover, we used a series of questionnaires and conducted clinical face-to-face interviews to assess the presence of psychiatric disorders and the severity of anxiety and depressive disorders.
In addition to examining psychiatric and developmental comorbidities, which may offer insight into the underlying mechanisms of misophonia, it is crucial to also consider other factors such as pre- and postnatal conditions and maternal well-being [
22‐
24] that could also play a role in development or maintenance of misophonia symptoms. Currently, there is a lack of information on such risk factors in misophonia. In this study, we assessed these aspects and compared its occurrence between individuals with misophonia and controls without any sound over-responsivities, using mother-reported data, including gathering data on the occurrence of postpartum depression following the birth of the assessed child.
For a better understanding of the mechanisms of misophonia, it is also crucial to establish a comprehensive description of the clinical presentation of this disorder in its early stages, including its progression and changes throughout childhood and adolescence. This information is vital for early detection and intervention, potentially leading to improved outcomes for those affected by misophonia. No studies examining age-related misophonia characteristics have been published so far. Therefore, in this study, we also compared the clinical presentation of misophonia in younger children and teenagers, including the presence of aggressive behavior and self-harm in response to trigger sounds, as well as coping strategies.
In summary, the main aim of this pilot study was to evaluate a broad range of preliminary findings from previous research on misophonia within a Polish sample of children and adolescents and develop new hypotheses to test in further studies. Specifically, the main objectives of this study were to:
-
describe the characteristics of misophonia in children and adolescents, including the age of onset, types of triggers, coping strategies, typical reactions to trigger sounds, emotional experiences, and reported direction of symptom development over time,
-
investigate differences in aggressive and self-harming behaviors and coping skills between younger children (aged 7–12) and teenagers (aged 13–18) with misophonia,
-
examine differences in perinatal characteristics, as well as somatic and psychosomatic complaints, between children with and without misophonia,
-
investigate differences in the severity of depressive and anxiety symptoms, as well as in the occurrence of ASD, ADHD, ODD, OCD, and tic disorders, between children with and without misophonia,
-
verify the emotional and social competencies of the assessed children with the performance-based tests,
-
investigate whether there were any differences in the occurrence of stressful events during pregnancy and post-partum depression between mothers of children with and without misophonia,
-
describe the prevalence of misophonia and autism in other family members of children with misophonia.
Discussion
This is one of the first studies on the characteristics of misophonia in children, and the first one to examine differences in misophonia characteristics between a group of younger individuals (aged 7–12) and older ones (aged 13–18). Additionally, it is novel here to investigate pre- and perinatal characteristics of such children, along with the occurrence of postpartum depression in their mothers. The entire misophonia sample was also compared to their non-misophonia peers in terms of health characteristics and emotional and social skills.
In the misophonia group, according to retrospective reports from the mothers, half of our sample exhibited the full symptoms of misophonia by the age of 7, with four children possibly meeting the criteria as early as at the age of 3 years. This suggests that misophonia may begin even earlier than previously reported [
5,
12]. If misophonia is observed in infants or toddlers, new ways of assessment appropriate for these age groups should be carefully developed. It may be more difficult to diagnose and distinguish misophonia from hyperacusis or other forms of decreased sound tolerance in children who are still not fully able to verbalize their needs than it is in school-aged youth. Furthermore, the correlation between the age of onset and the age of the assessed child suggests that individuals assessed at a later age may be less likely to recall early experiences with misophonia. These findings emphasize the significance of studying children with misophonia and involving their parents. Early detection of misophonia and well-planned and executed interventions may potentially prevent or mitigate the adverse long-term effects of misophonia on mental health and family life, which warrants careful investigation in future studies.
Although the first trigger for the majority of children (64%) was a sound made by a family member, for the rest of the group, it was either a non-family member or both (family and non-family). Moreover, when asked about their current main or worst triggers, this percentage dropped, and only 50% of children were mainly triggered by family members. These results confirm notions that sounds made by family members are discerned triggers, but also show that it is not an indispensable characteristic of misophonia. The high percentage of participants for whom the first trigger was a family member may be explained by the fact that children spend most of their time with family members, and specific, repetitive sounds triggering misophonia are more likely to occur in proximity.
In this study, we explored for the first time the differences in clinical presentation of misophonia in younger and older age groups of children and adolescence. Our findings revealed that physical and verbal aggression is very common in misophonia, but only in younger children aged 7–12 years old. Physical aggression was reported in only 7% of the teenage group. However, almost a half of the teenagers assessed in this study reported self-harm while being exposed to trigger sounds. It can be assumed that emotional distress and psychophysiological arousal related to misophonia may exceed the capabilities of younger children to respond in socially acceptable ways. Frequent verbal and physical aggression in children and teenagers with misophonia were also found in [
6]. Our data indicate that externalizing behaviors in response to misophonic triggers might decrease with age, possibly along with an increase in self and social awareness and inhibitory control. However, as our data suggest, misophonia-related distress does not decrease and is frequently managed in a dysfunctional, self-destructive way, such as self-harm. Further, longitudinal studies should verify these results.
Despite the high rate of verbal and physical aggression reported in the younger misophonia sample, it is worth noting that there was no difference in the occurrence of ADHD and ODD between the misophonia group and the control group. The prevalence of ADHD in the misophonia group was very similar to that reported by Guzick et al. [
6] when applying the DSM-5 criteria. In our study, 26% of the children met the criteria for some type of ADHD, while Guzick et al. [
6] reported a prevalence of 21%. However, it is important to note that when applying the ICD-10 criteria, which are still official in Poland, the percentage of ADHD in the misophonia group dropped to 5%. Thus, it is crucial to consider the type of diagnostic criteria when comparing the data. Notably, [
6] also found no significant difference in externalizing behavior between children with misophonia and those with anxiety disorders. What is more, Smit et al. [
40] in the genome-wide association study did not find a genetic correlation between misophonia and aggression. However, they found significant correlations with the neuroticism cluster which holds internalizing traits. Therefore, our results, together with those from the other studies, support the notion that misophonia should be rather seen as an internalizing disorder. Externalizing behavior sometime observed in misophonia may be specifically related to the inability to overcome the psychophysiological response evoked by misophonic triggers, rather than a general way of reacting to various situations. This should also be verified in further studies, for example by comparing children with misophonia to those with externalizing disorders.
Clinicians should be aware that misophonia in children and adolescents can manifest in different ways and may not always involve externalizing behaviors such as verbal or physical aggression. Therefore, screening for self-harm and other related symptoms should also be a part of the diagnostic process for misophonia, particularly in cases where externalizing behaviors may not be apparent.
Another result of this study that indicates the need for careful psychiatric and psychological evaluation of children and teenagers with misophonia is related to depressive symptoms. Notably, when compared to controls without misophonia, children with misophonia on average had significantly higher self-reported depressive symptoms, but there was no difference in the parent reports. However, when analyzing the number of children whose results indicated clinically elevated depressive symptoms (according to norms adjusted for age in Poland), both self and parent reports indicated possible higher prevalence of this disorder in the misophonia group. A similar pattern of more apparent self-reported symptoms was found in the case of anxiety disorders. Only the symptoms of Generalized Anxiety Disorder were increased in the misophonia group according to both child and parent assessment, while symptoms of social phobia as well as panic and agoraphobia were significantly increased only when self-assessed by the children.
However, these results should be interpreted with caution for at least two reasons. Firstly, the majority of missing data in the depression and anxiety questionnaires was from younger children, many of whom were either too tired or unable to complete them. As a result, the mean age could be higher in the case of self-report compared to parental reports. Secondly, while we adjusted the data for age according to Polish norms for depressive symptoms, which makes the data more reliable in spite of the mentioned limitation, we used raw data for anxiety scales due to the lack of Polish norms for these questionnaires.
It is interesting to note the discrepancies in the assessment of OCD symptoms. Specifically, when children self-reported their OCD symptoms, there were no group differences. However, when assessed in the interview according to ICD-10 criteria, OCD was significantly more frequent in the misophonia group (13.6% vs. 0). In other words, the binary diagnosis made the difference statistically significant. Notably, in the dimensional parent-rated assessment of child OCD symptoms, although the difference was not statistically significant, the OCD symptoms were higher in children with misophonia, indicating a statistical tendency.In a study by [
6], the diagnosis of OCD was also among the highest prevalent disorders (13%). These findings suggest that the use of multiple assessment methods as well as different sources of information, including self-report, parent report, and clinical interview may be useful for better identification of comorbid conditions in pediatric misophonia, especially in research, when the time for a diagnosis is more limited than in a clinical setting. The discrepancies between measurements, which also occurred in this study, can result from specific properties of the measurement tools, as well as from limited insight into their own psychopathology in children. It is also important for future studies to employ standardized interviews, such as MINI-KID [
41], to ensure a higher quality of psychiatric assessment. In this study, due to constraints in resources, we were unable to do so.
The results showed that although children with misophonia had a relatively high rate of comorbid tic disorders (18%), there was no statistically significant difference compared to the control group (5%). However, due to time limitations, we did not use a dimensional scale to assess the severity of tic disorder symptoms, which could possibly show the whole spectrum and intensity of the phenomenon. Therefore, caution is advised when interpreting these results. Nonetheless, a similar (13%) rate of tic disorder in children with misophonia was discovered by Guzick et al. [
6].
It was previously reported that misophonia might be related to migraines [
7]. In our sample, children with misophonia indeed significantly more often experienced migraine or strong headaches, than controls, as reported by their parents. They also had a higher rate of psychosomatic complaints. The groups did not differ in occurrence of epilepsy, head injuries, and tinnitus. It should be further explored whether this correlation could be attributed to higher stress exposure or lower abilities of emotional regulation., such as for example emotional suppression.
In this study, we also aimed to investigate whether any prenatal, perinatal, or early childhood medical events could increase the risk of misophonia. We found no group differences in terms of delivery method, birth complications, prematurity, or maternal-reported stress during pregnancy with the assessed child. Nonetheless, these results also should be treated as preliminary and replicated with a use of more objective data, such as inclusion of medical records. Mothers of children with misophonia reported a significantly higher incidence of postpartum depression compared to mothers of children without misophonia. Further research is necessary to explore the emotional well-being of parents of children with misophonia, particularly regarding postpartum depression, as it has been already shown it may increase the risk of psychopathology [
42,
43]. While we evaluated different aspects of parental functioning in this research project, it is not feasible to discuss them in detail within the scope of this paper due to its length.
Another finding that underscores the importance of focusing on families, both in terms of environmental and genetic factors, is that in over 50% of cases within the misophonia group, misophonia was found in at least one other member of the family. Although there are no twin studies on misophonia, some other data suggest a substantial impact of genetics factors. For example, the recent study by Smit et al. [
40] showed 8.5% SNP-based heritability of misophonia. In this study, the prevalence of misophonia was not checked in the control group because participants were not chosen randomly from the population, and people who were already familiar with misophonia could volunteer for the study. To leverage knowledge on the family prevalence of misophonia, further studies should choose the comparison group randomly so that the epidemiological data are not biased.
Furthermore, in our misophonia group, the occurrence of autism in the family was high, although there were no significant group differences (30% vs. 16%). However, as mentioned above, there was a high risk that specific people might have applied to the control group, which could have biased the results. Therefore, further studies are needed to investigate the potential association between misophonia and autism in families using random sampling to reduce any potential bias. Particularly, misophonia symptoms could be explored in the context of the broader phenotype of autism [
44]. Nonetheless, we found that children with misophonia did not differ significantly from the control group in terms of the severity of their ASD symptoms. In the largest study on children with misophonia to date, Guzick et al. [
6] found that ASD symptoms were actually higher in the anxiety control group than in the misophonia group. Smit et al. [
40] found even a negative correlation with autism in their study. In contrast, Rinaldi et al. [
18] found a relationship between misophonia symptoms and ASD symptoms in both children and adults. However, the differences between their study and ours could be attributed to the broader definition of misophonia used by Rinaldi et al. [
18] compared to the one defined by Jager et al. [
3] as well as to the method of the data collections (questionnaire online vs. face-to-face interviews). The definition and measurement of misophonia can significantly impact its correlates, as demonstrated in Siepsiak et al. [
8]. Therefore, when exploring the relationship between misophonia and ASD, it is crucial to carefully consider the definition and measurement of misophonia to ensure the accuracy of findings.
The outcome of our study, which found no relationship between misophonia and social difficulties measured by autism questionnaire assessment, is supported by the fact that the children with misophonia did not differ from their peers in tests measuring social competencies, nor were there differences in the test measuring emotional competencies. Further studies should examine whether the same results will be obtained in misophonia triggered primarily by non-oral or nasal human-made sounds, as this might be more related to sound over-responsivity prevalent in ASD, and using other measures of emotional and social functioning, including behavioral observations made by teachers.
A major limitation of this study is the small sample size. This problem could lead to the II type error, therefore—some differences between the groups could have not been detected. However, it should be noted that the study was intended to be a pilot study for a more comprehensive and expensive investigation into pediatric misophonia in Poland. Another significant limitation is the lack of a questionnaire to assess misophonia symptoms in children in Polish language, which prevented the exploration of the relationship between the severity of misophonia symptoms and other psychopathologies. Future research in Poland should prioritize the validation of existing child misophonia questionnaires (e.g. [
17,
18,
45,
46]) to improve the accuracy of misophonia assessment in research and clinical practice. Another weakness of the study, which is also related to the lack of appropriate tools in Polish, is that we did not assess the comorbid hyperacusis in the misophonia group. We believe that this should be addressed in future studies.
There is also a scarcity of validated questionnaires in the Polish population for assessing other psychopathological symptoms in children. For instance, the SCAS was only validated in a group of teenagers and solely in the self-report version. Unfortunately, the cost of using better quality tools exceeded the budget of this pilot study. Furthermore, although there was no statistically significant age difference between the groups, it is worth noting that the misophonia group was, on average, one year older than the control group. In this developmental stage, even a one-year age difference can potentially result in significant qualitative differences, particularly when considering the prevalence of psychopathology symptoms. Regarding the age of onset of misophonia, this study provides only retrospective information; it would be valuable to conduct a longitudinal study where the younger siblings of children with misophonia are followed. Lastly, in future studies, the misophonia group should be compared to other clinical groups, such as a group of children with anxiety disorders [
6] or externalizing disorders, to explore mechanisms that overlap with other psychopathologies and those specific to misophonia.