The Relationship Between Interoceptive Awareness, Emotion Regulation and Clinical Symptoms Severity of Depression, Anxiety and Somatization

Su Jin Lee; Mimi Lee; Hyeong Beom Kim; Hyu Jung Huh

doi:10.30773/pi.2023.0221

Psychiatry Investig > Volume 21(3); 2024 > Article

Lee, Lee, Kim, and Huh: The Relationship Between Interoceptive Awareness, Emotion Regulation and Clinical Symptoms Severity of Depression, Anxiety and Somatization

Original Article

Psychiatry Investigation 2024;21(3):255-264.

Published online: March 25, 2024

DOI: https://doi.org/10.30773/pi.2023.0221

The Relationship Between Interoceptive Awareness, Emotion Regulation and Clinical Symptoms Severity of Depression, Anxiety and Somatization

Su Jin Lee¹

, Mimi Lee²

, Hyeong Beom Kim³

, Hyu Jung Huh^4,⁵

¹Department of Psychology, Ewha Womans University, Seoul, Republic of Korea

²Department of Psychology, The Catholic University of Korea, Seoul, Republic of Korea

³Department of Social Welfare, Soongsil University, Seoul, Republic of Korea

⁴Department of Psychiatry, Incheon St. Mary’s Hospital, The Catholic University of Korea, Incheon, Republic of Korea

⁵Department of Psychiatry, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea

Correspondence: Hyu Jung Huh, MD, PhD Department of Psychiatry, Incheon St. Mary’s Hospital, The Catholic University of Korea, 56 Dongsu-ro, Bupyeong-gu, Incheon 21413, Republic of Korea Tel: +82-32-280-7495, Fax: +82-32-280-7495, E-mail: arbor99@catholic.ac.kr

Received July 2, 2023 Revised September 27, 2023 Accepted December 3, 2023

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Objective

The primary objective of this study was to examine the associations among emotion regulation strategies, interoceptive awareness, and psychological distress measures—namely, depression, anxiety, and somatization. Additionally, we aimed to explore the predictive power of various facets of interoceptive awareness in determining the severity of symptoms for each mental disorder.

Methods

A cohort of 130 outpatients diagnosed with depression/anxiety disorder were recruited, and 20 subjects exhibiting incomplete responses were excluded from the dataset, leading to a final sample size of 110 outpatients. The clinical symptoms were measured by Patient Health Questionnaire-9, State-Trait Anxiety Inventory Form Y, and Symptom Checklist-90-Revised, and the usage of emotion-regulation strategies and interoceptive awareness was assessed with Emotion Regulation Questionnaire and Multidimensional Assessment of Interoceptive Awareness (MAIA), respectively. A hierarchical regression analysis was performed to examine whether emotion-regulation strategies and interoceptive awareness explain the statistically significant variance in each of the symptoms.

Results

In the depression model, cognitive reappraisal, accept, and attention regulation showed significant associations, while in the anxiety model, cognitive reappraisal, attention regulation, trust, and notice emerged as significant factors. Lastly, cognitive reappraisal and attention regulation were found to be significant contributors to the final model for somatization.

Conclusion

The inclusion of MAIA subscales improved the predictive ability of the regression model, highlighting the independent association between interoceptive awareness—particularly attention regulation—and clinical symptoms of anxiety and depression. Additionally, the study underscores the relevance of considering the specific pathological context when implementing interventions, as evidenced by the positive associations between the accept subscale and depression and between the notice subscale and anxiety, respectively.

Keywords: Anxiety disorder, Depressive disorder, Interoception, Emotional regulation

INTRODUCTION

Emotion is not merely a feeling but instead a whole-body phenomenon that brings changes in one’s subjective experience, physiology, and—most importantly—action tendencies [1]. Emotions arise when an individual evaluates a situation in relation to their survival, well-being, or other goals [2], and as implied by the inclusion of “motion” in the term, they encourage an individual to act in a certain way to increase the chances of attaining the goal that gave rise to the emotions in the first place [3]. However, when such emotional reactions—either positive or negative—are not managed appropriately, they may interfere with adaptive functioning of individuals and cause subjective distress, leading to some mood disorders such as anxiety and depression [4].

Emotion regulation refers to a process in which the occurrence, intensity, duration, and expression of emotions are modified. It has been observed that individuals with depression and anxiety often experience intense and overwhelming emotions, along with difficulties in accurately identifying and labeling their emotions. These challenges can hinder their ability to effectively manage their emotional responses [4]. Furthermore, it has been suggested that difficulties in regulating emotions are due to a failure in selecting and implementing emotion-regulation strategies that are considered adaptive [4]. One of the strategies that has been identified as effective is cognitive reappraisal, which involves a reinterpretation of emotion-eliciting situations in a way that alters one’s emotional response to the situation [5]. Numerous studies have found that frequent use of cognitive reappraisal is related to reductions in negative affects [6] as well as fewer depression and anxiety symptoms [7,8]. On the other hand, expressive suppression has long been considered a maladaptive regulation strategy by which an individual attempts to hide, inhibit, or reduce affective expressions once emotions arise. Considerable evidence indicates how engaging in expressive suppression aggravates rumination [9], negative emotions, and subjective distress [10], leading to the onset and maintenance of anxiety, depression and eating disorders [7,11].

In addition, it has been postulated that interoception, or an afferent processing of physiological signals, plays an important role in the subjective experience of emotions [12]. The existence of such a mind-body relationship where emotional experiences result from a physiological process was first proposed by James [13] and Lange [14] and later validated by numerous functional magnetic resonance imaging data suggesting how changes in the body states (e.g., heart rate, muscle contraction, posture, facial expression) produce neural patterns that are perceived as emotions [15]. Specifically, the brainstem, insular cortex, and somatosensory cortex are found to be responsible for integrating and translating visceral states into subjective feelings [16-18]. Moreover, research has shown that the disruption of interoceptive signaling is associated with emotion and stress regulation [19,20], leading to a variety of mental disorders such as anxiety, depressive disorders, and somatic symptom disorders [21]. For instance, substantial evidence suggests a link between depression and blunted cardiac interoceptive awareness, where depressed patients demonstrate lower accuracy in counting heartbeats compared to healthy individuals and other patients with anxiety disorders [22,23]. Additionally, there are studies that suggest individuals with anxiety disorders may experience heightened alertness and hypervigilance of bodily sensations, potentially exacerbate their anxiety [20,23].

Interoception, however, cannot be sufficiently understood by displaying objective accuracy in detecting internal bodily signals like the heartbeat. Growing studies are now focusing on the ways in which individuals attend and respond to interoceptive stimuli under the influence of cognitive processes like beliefs, historical input, and social and cultural contexts [24,25]. The Multidimensional Assessment of Interoceptive Awareness (MAIA) was recently developed to address multiple dimensions of such subjective perception of bodily sensations and includes subscales that measure the awareness of body sensations, attentional and emotional reactions to sensations, attention regulation, and the individual’s style and capacity for mind-body integration [25]. Several studies found that a lack of body trust [26] and impairment in attention-regulation skills are inversely related to depression and somatoform disorders, while not distracting oneself from painful or uncomfortable sensations is positively associated with such [27,28]. Similarly, trust and attention regulation as well as the interaction between the two have been noted as key predictors of anxiety and emotional susceptibility [29-31].

Moreover, third wave therapies which include forms of contemplative practice or mindfulness-based intervention challenge existing model of ‘top-down’ or intended regulation of emotion by asserting that attempts to control the emotional experience itself may be a problem [24]. Appraisals that follow after perceptions facilitate an active regulatory response, which requires ‘doing’ rather than simply ‘being’ with unexpected sensation. Doing mode requires one to redirect attention away from the body toward response formulation, which includes application of top-down regulatory strategy toward external stimuli that have generated the emotion. However, the emotional symptoms of depression and anxiety disorder often lack an actual external trigger but are characterized by internally elevated emotional arousal states and thus require different strategy. There are several studies that assisted how directing one’s awareness to actual emotions and bodily feelings without conscious intention to regulate them decreased amygdala activity, indicating attenuating influence on emotional arousal, whereas top-down reappraisal strategy resulted in a paradoxical increase of amygdala activity [32,33]. Together, these findings underscore the clinical significance of interoceptive awareness, suggesting that the regulation of bodily sensations is equally as crucial as the regulation of emotions in the assessment and treatment of depression/anxiety disorders.

Notably, to the best of our knowledge, however, there is a paucity of studies that have directly compared the impact of bottom-up strategies that focuses on bodily sensations with that of top-down strategies that focuses on emotion. Therefore, our study hypothesizes that emotion-regulation strategies, such as cognitive reappraisal and expressive suppression, as well as interoceptive awareness are significantly associated with the severity of clinical symptoms in depression, anxiety, and somatization. Furthermore, our research aims to examine the relative importance of interoceptive awareness and emotion-regulation strategies in relation to the severity of each clinical symptom (depression, anxiety, somatization). Additionally, by exploring the predictive power of the subscales of MAIA for each clinical symptom’s severity, we aim to identify specific aspects of body awareness that warrant special attention. This deeper understanding of the role of interoceptive awareness is expected to broaden the scope of clinical interventions, which have traditionally focused on emotion regulation, and contribute to the development of more effective treatment programs.

METHODS

Participants

Patients who visited the Mood and Anxiety Disorders Unit at Incheon St. Mary’s Hospital, The Catholic University of Korea were recruited for the study during the period from August 5, 2021 to February 18, 2022. Total of 130 patients were recruited, and they all had a principal diagnosis of nonpsychotic depressive disorder and anxiety disorder based on the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) diagnostic criteria. These diagnoses were made by a psychiatrist using Structured Clinical Interview for DSM-5 disorders [34], and the exclusion criteria included a lifetime diagnosis of psychotic disorder, bipolar disorder, mental retardation, or any mental disorder resulting from a general medical condition. Patients were eligible if they were 18-65 years old and literate in Korean. Thorough explanations of the study were provided to the patients, and informed consent was obtained. Upon data collection, 20 samples exhibiting incomplete responses were excluded from the analysis, resulting in a final dataset comprising 110 samples. All research procedures were subjected to review and approved by the Institutional Review Board of the Catholic University of Korea Incheon St. Mary’s Hospital (approval no. OC21FISI0055).

Study measures

MAIA

Interceptive Awareness was assessed with the Korean version of MAIA (K-MAIA), a 32-item instrument measured on a 7-point Likert scale (0=never, 6=always). K-MAIA is composed of 6 scales—namely, notice, accept, attention regulation, mind-body connection awareness, return to body, and trust. The Cronbach’s α values of these six scales measured in the validation paper ranged from 0.80-0.90 (total, 0.94), showing adequate internal consistency [35]. The notice scale measures the awareness of body sensations that are comfortable, neutral, and uncomfortable. Accept refers to not feeling emotionally distressed and not ignoring or distracting oneself from uncomfortable body sensations like pain. Attention regulation assesses the ability to maintain and regulate attention to body sensations, and mind-body connection awareness is defined as awareness of the interrelation between body sensations and emotional states. Return to body refers to the ability to consciously attend to body sensations to control psychological distress and gain insight. Lastly, trust refers to experiencing one’s body as safe and trustworthy. Cronbach’s α values were assessed to evaluate internal consistency and were shown to be acceptable, ranging from 0.69-0.88 (notice, 0.92; accept, 0.69; mind-body connection awareness, 0.83; return to body, 0.88; trust, 0.84) with a total value of 0.90.

Emotion Regulation Questionnaire

The Emotion Regulation Questionnaire (ERQ) is a 10-item instrument that assesses individual differences in the tendency to use two emotion-regulation strategies—namely, cognitive reappraisal and expressive suppression. Cognitive reappraisal is an antecedent-focused strategy where one tries to reinterpret the emotion-eliciting situation in a way to alter the emotional response. On the other hand, expressive suppression focuses on modulating the emotional response, and it involves hiding or suppressing emotional expression [36]. The ERQ score is calculated using a 7-point Likert scale (1=strongly disagree, 7=strongly agree), with higher scores indicating greater usage of the strategy. In the current study, the Korean version of ERQ was used, and the Cronbach’s α value was 0.78, showing adequate internal consistency, which was also determined in Shon’s validation paper (Cronbach’s α for cognitive reappraisal: 0.85; Cronbach’s α for expressive suppression: 0.73) [37].

Patient Health Questionnaire-9

The Patient Health Questionnaire-9 (PHQ-9) is a self-report instrument used to diagnose, monitor, and assess the severity of depression. It is composed of 9 items that correspond to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Diagnostic Criterion A Symptoms of Major Depressive Disorder and it asks participants to answer based on the past 2 weeks. The items are assessed on a 4-point Likert scale (0=not at all, 3=nearly every day), and a score of 9 points has been suggested as an optimal cutoff point for screening for major depressive disorder [38]. The Cronbach’s α value of the Korean version of PHQ-9 measured in the validation study (0.95) as well as in this present study (0.91) were both >0.9, indicating an excellent level of internal reliability [35].

State-Trait Anxiety Inventory Form Y

The State-Trait Anxiety Inventory (STAI) is a self-completed questionnaire that measures one’s tendency to experience anxiety. With the construct of two 20-item scales measured on a 4-point Likert scale (1=not at all, 4=very much so), the STAI distinguishes state and trait anxiety. State anxiety refers to a transitory state of emotion at the time of a perceived threat, and it is characterized by physical arousal and consciously felt feelings of dread, apprehension, tension, and so on [39]. In contrast, trait anxiety refers to a more generalized and enduring predisposition to be anxious in various situations, which even includes daily routines that are innocuous. The Korean adaptation of Spielberger’s STAI was used for the current study, and the Cronbach’s α values reported in a previous validation study [40] and this study were 0.92 and 0.96, respectively, both showing an excellent level of internal reliability.

Symptom Checklist-90-Revised

The Symptom Checklist-90-Revised (SCL-90-R) is a widely used self-report questionnaire developed to measure psychological distress [41]. It has nine symptomatic dimensions, each evaluating different psychological symptoms such as depression, anxiety, somatization, interpersonal sensitivity, hospitality, and so on. In the current study, only somatization dimension was used to measure the degree of somatic symptoms. This dimension is comprised of 12 items measured on a 5-point Likert scale (1=not at all, 5=extremely), and raw scores of ≥22 and ≥27 points represent severe levels of somatic symptoms for men and women, respectively [42]. The Cronbach’s α value (0.97) reported in Im’s validation study of the Korean version of SCL-90-R as well as that in the present study (0.89) both indicate good internal reliability [43].

Statistical analysis

All of the statistical analyses in this study were performed using SPSS Statistics version 28.0 (IBM Corp., Armonk, NY, USA). First, descriptive analysis was conducted to summarize the demographic and clinical characteristics of the sample and verify the normality of the data. Then, Pearson’s correlation matrix was calculated to investigate the degree of the linear relationship among pathological variables (anxiety, depression, somatization), emotion-regulation strategies (cognitive reappraisal, expressive suppression), and interoceptive awareness (notice, accept, attention regulation, mind-body connection awareness, return to body, trust) in a dataset. Lastly, hierarchical regression analysis was used to examine whether predictors explain statistically significant variance in each of the dependent variables—namely, anxiety, depression, and somatization. The initial steps of the independent variables were as follows: cognitive reappraisal and expressive suppression were assessed first, and subscales for MAIA were examined next. This order was determined using previous research that presented the effect of emotion-regulation strategies on emotional disorders [5].

RESULTS

Demographic and clinical characteristics

Table 1 presents demographic characteristics of the sample. Subsequently, the age distribution is presented in a descending order: 20-29 years (n=43, 39.1%), 40-49 years (n=25, 22.7%), 30-39 years (n=19, 17.3%), 50-59 years (n=18, 16.4%), and 60-65 years (n=2, 1.8%). Predominantly, the majority of the sample were of the female sex (n=80, 72.7%), while more than half of the participants reported a single marital status (n=64, 58.2%). Furthermore, the majority of the sample possessed a minimum educational attainment of high school diplomas (n=45, 40.9%), 20 having completed an associate degree (18.2%), and 22 attaining a bachelor’s degree (20.0%). Among the study participants, 43 individuals were diagnosed with depressive disorder, while 67 received a diagnosis of anxiety disorder, and total of 13 patients exhibited comorbidity. Notably, major depressive disorder (n=36, 32.7%) and panic disorder (n=36, 32.7%) constituted the most prevalent diagnostic categories with the sample.

Descriptive and correlation analysis

Table 2 presents a comprehensive overview of descriptive statistics and the results of the correlation analysis for the test variables. Notably, the mean scores for cognitive reappraisal and expression both fell within the range of 4. However, among the MAIA subscales, only the subscale of mind-body-connection exhibited mean score around 4. Additionally, the average levels of clinical symptoms stood at 11.98 for depression, 113.07 for combined scores of trait and state anxiety (54.21 for state anxiety alone), and 26.16 for somatization.

Among the test variables, cognitive reappraisal showed the strongest association with all of the emotional disorders in a negative direction; specifically, cognitive reappraisal was moderately associated with depression (r=-0.48) and somatization (r=-0.43) and showed a strong association with anxiety (r=-0.62) at the significance level of 0.001. On the other hand, there was no substantial correlation between emotional disorders and the subscale of expressive suppression. Among MAIA subscales, attention regulation, return to body, and trust demonstrated statistically significant negative relationships with all of the emotional disorders, displaying a moderate association with anxiety (r=-0.47 to -0.54, p<0.001) and a weak to moderate association with depression (r=-0.38 to -0.44, p<0.001) and somatization (r=-0.24 to -0.39, p<0.01). However, the correlation between the emotional disorders and the subscales of notice and accept were insignificant with the significance level of >0.05, while mind-body connection awareness showed a weak association with depression (r=-0.16, p<0.05) and anxiety (r=-0.25, p<0.01).

Hierarchical regression analysis

Depression, anxiety, and somatization were examined individually as dependent variables, and the results are presented in Table 3. First, in the depression model, cognitive reappraisal and expressive suppression were entered in the first step, and they accounted for 24% of the variance in the PHQ-9 score. MAIA subscales, entered in the second step, accounted for an additional 6% of the variance (adj. R²=0.30, F=2.52, p<0.05). In the final model, cognitive reappraisal (β=-0.31), accept (β=0.18), and attention regulation β=-0.26) showed a significant beta weight, with cognitive reappraisal and attention regulation having a negative coefficient, and accept having a positive coefficient. Such results imply that greater levels of cognitive reappraisal and attention regulation correlate with lower levels of depression, while higher levels of accept are associated with more severe depression. Second, the amount of variance explained by emotional strategies was 39% for anxiety, and the addition of MAIA subscales to this model increased the variance by 9% (adj. R²=0.48, F=3.81, p<0.01). Cognitive reappraisal (β=-0.42), attention regulation (β=-0.17), trust (β=-0.27), and notice (β=0.19) were presented as significant predictors in the final model, where greater usage of the first three strategies correlates with lower levels of anxiety, while greater usage of notice relates to higher levels of anxiety. Lastly, emotional strategies accounted for 21% of the variance of somatization, and this variance increased by 7% after adding interoceptive awareness variables (adj. R²=0.28, F=2.72, p<0.05). cognitive reappraisal (β=-0.35) and attention regulation (β=-0.26) showed significant negative coefficients in the final model, implying that greater levels of cognitive reappraisal and attention regulation were linked to reduced severity of somatic symptoms.

DISCUSSION

The purpose of this study was to assess the role of interoceptive awareness and emotion-regulation strategies in determining depression, anxiety, and somatization symptoms and to identify optimal predictors of each mental disorder. First, normality of the data was confirmed, where the measures of skewness and kurtosis for all variables fell within acceptable ranges (skewness: ±3, kurtosis: ±10) [44]. Also, the symptom validity was assessed with the mean scores of clinical symptoms, and the scores were of close proximity to or surpassing the designated cutoff values, indicating a severe level of clinical symptoms (PHQ-9 >9; State Anxiety of STAI >40; SCL-90-R within the range of 22-27) [38,40,42].

For emotion-regulation strategies, both correlation and hierarchical regression analyses support the findings of prior reports that tied less frequent habitual use of cognitive reappraisal to greater depression/anxiety disorder severity [7,8,45,46]. The results concerning expressive suppression, however, were inconsistent with those of prior literature in that they did not reveal any significant association with depression/anxiety disorders and somatization. Expressive suppression has been consistently considered a maladaptive regulation strategy [7,11], but some studies have suggested that psychopathologic symptoms may not be associated with expressive suppression itself but instead with the specific emotion being suppressed [47]. In addition, its adverse effect may depend on the cultural context. For example, in Asian culture where suppressing emotional response is normative, expressive suppression was found to be irrelevant with the psychological functioning [48]. Clearly, further studies are needed to examine the interplay of expressive suppression in depression and anxiety.

Moreover, the addition of MAIA subscales to the regression model improved the model’s predicting power by 6%-9%, indicating how interoceptive awareness is independently associated with the clinical symptoms of depression, anxiety, and somatization above and beyond the contribution of emotion-regulation strategies. Specifically, attention regulation showed a negative association with all of the clinical symptoms, demonstrating how individual’s ability to perceive and attend to their internal bodily sensations without becoming distracted or overwhelmed is crucial for improving emotional regulation and overall mental health. This current finding is consistent with results of prior research that highlighted the effect of attention regulation on emotion regulation skills as well as symptoms of panic disorder and depression [35,49,50]. A possible explanation for such an effect of attention regulation is that sustaining and regulating attention on internal sensory experience disassociates the rigidly constrained perception-appraisal associations, allowing inner distancing from the feelings as well as from ruminating negative thoughts and emotions and thus lead to better emotion regulation and stress coping [51]. Additionally, attention regulation may play a protective role by allowing flexible application of emotion regulatory strategies tailored to a given situation, and thus improving emotion regulation and reduce the intensity of the symptoms [52]; this is well supported by studies that have proven the therapeutic effect of mindfulness-based interventions that aimed to improve attention regulation [53]. Together with these prior studies, our results provide empirical evidence for the necessity of considering interoceptive awareness when establishing a treatment plan for depression/anxiety disorders.

Other features that deserve attention are the interplay of accept in depression and notice and trust in anxiety. Unlike all other variables that showed a negative association, accept and notice showed a positive association with depression and anxiety, proposing that high levels of accept and notice may be risk factors depending on the pathological context in which each is manifested. Though many studies suggest that there’s a negative association between the accept subscale and depression [54,55], there may be some situations in which accept leads to passivity or inaction. For example, when an individual experiences bodily sensations that are consistently negative and distressing, such as fatigue, yet does not take action to address the underlying causes of this sensation, it could result in negative consequences, including continued emotional distress, decreased motivation to make positive changes, and a sense of helplessness or hopelessness. However, it is important to note that the studies show mixed results about the relationship between the accept subscale and depression, and further research is needed to better understand the mechanisms underlying this relationship. Also, the results of how notice and anxiety symptoms positively relate are consistent with those of the prior studies that argued how excessive monitoring and scrutiny of bodily sensations and internal experiences can exacerbate symptoms of anxiety and may contribute to the development and maintenance of symptoms [56-58]. Several studies, however, have suggested that, instead of employing strategies to suppress or divert attention, a more effective approach for pain and stress relief involves acute sensing and perception of bodily sensations [59,60]. These mixed research findings in the literature may stem from a lack of clarity in defining the concept of “notice,” in that its frequency, duration, and contextual factors are not precisely delineated. Consequently, while the results of the current study demonstrate an association between perception and anxiety, it is imperative to conduct a more comprehensive examination to determine whether the positive association between notice and anxiety is solely attributed to the act of noticing itself or if other contributing factors should also be taken into account. Additionally, it is worth noting that, among all the subscales of MAIA examined, trust exhibited the strongest association with anxiety, indicating the significance of perceiving one’s bodily sensations as safe and trustworthy. In other words, a negative interpretation of perceived sensations may lead to anxiety, as prior research has already established evidence for such a relationship [61,62]. Lastly, a number of investigations have put forth propositions regarding the potential linkage between excessive attention to bodily signals and somatization [63,64]. Nevertheless, only attention regulation emerged as a significant factor, aligning with the accumulating body of evidence that emphasizes the influence of top-down factors, such as the interpretation of perceived sensations, rather than the precise perception of interoceptive cues itself [65].

The limitations of this study are as follows. First, since this study was a cross-sectional investigation, it is difficult to draw predictive conclusions about the causal relationship between the variables. Follow-up data from later time points would help clarify the factors that have causal effects on the severity of depression/anxiety disorders. Second, the self-report questionnaire employed in this study has limitations in effectively and reliably assessing interoceptive awareness. The respondents may have provided responses that are biased or distorted due to their inadequate comprehension regarding unfamiliar terminology, such as “observing” and “sustaining the awareness” of sensory experiences. Lastly, the sample was not divided to achieve the minimum required for high-powered hypothesis testing. The elucidation of the interrelationship between interoception and clinical symptoms may have been clearer if subgroups based on depression and anxiety disorders had been formed. Thus, a follow-up study employing a larger participant cohort, categroized according to their primary diagnosis, emerges a compelling avenue for subsequent investigation. Furthermore, comorbidities were not included as covariates in the present study, which could have potentially influenced the results. Nonetheless, the study’s findings offer compelling evidence of the significance of the relationships between interoception and clinical symptoms, even in the absence of consideration for comorbidities. For instance, attention regulation is uniquely and independently associated with clinical symptoms of both anxiety and depression, indicating how it retains its significance as a predictor of anxiety and depression symptoms even when comorbidities are taken into account. Additionally, the study highlights the nuanced relationships between specific aspects of intereroceptive awareness, such as accept and notice, and the severity of clinical symptoms. This robust evidence enhances the generalizability of the study’s results, implying that the relationships unveiled hold meaningful implications across various pathological context, thereby informing tailored interventions.

In conclusion, this study aimed to investigate the role of interoceptive awareness and emotion-regulation strategies in mitigating the symptoms of depression, anxiety, and somatization and to identify optimal predictors for each mental disorder. The findings pertaining to emotion-regulation strategies support prior research that has suggested a link between less frequent use of cognitive reappraisal and greater severity of clinical symptoms [7,8]. However, the results regarding expressive suppression did not align with previous literature, suggesting a need for further exploration of its association with clinical symptoms. Consequently, these results imply that interventions aimed at improving cognitive reappraisal are particularly crucial in mitigating symptoms of depression, anxiety, and somatization.

Additionally, the inclusion of the MAIA subscales enhanced the predictive power of the regression model, highlighting the independent association between interoceptive awareness, specifically attention regulation, and clinical symptoms of anxiety/depression disorders. The significant association between attention regulation and all of the clinical symptoms suggests that interventions aimed at enhancing the capacity to maintain attention on bodily sensations without becoming distracted or overwhelmed can have a significant impact on addressing symptoms related to emotional regulation. These interventions, which often involve practices such as mindfulness, yoga, and somatic experiencing, go beyond simply improving one’s sensitivity to bodily sensations and instead focus on cultivating a non-judgmental attitude toward perceived sensations. The current findings provide experiential evidence for the therapeutic effects of these interventions in managing symptoms [54,66]. Furthermore, notable observations were made regarding the interplay of accept with depression and notice with anxiety, with positive associations within the respective pairings. These findings underscore the significance of taking into account the pathological context in which a particular intervention is implemented. Overall, this study makes a valuable contribution to the development of interventions that are more precisely tailored to each mental disorder.

Notes

Availability of Data and Material

The datasets generated or analyzed during the study are available from the corresponding author upon reasonable request.

Conflicts of Interest

The authors have no potential conflicts of interest to disclose.

Author Contributions

Conceptualization: Hyu Jung Huh. Data curation: all authors. Formal analysis: Su Jin Lee. Funding acquisition: Hyu Jung Huh. Investigation: all authors. Methodology: Hyu Jung Huh, Su Jin Lee. Visualization: Su Jin Lee. Writing—original draft: Su Jin Lee. Writing—review & editing: Su Jin Lee, Hyu Jung Huh.

Funding Statement

This research was supported by a grant of Translational R&D Project through the Institute for Bio-Medical convergence, Incheon St. Mary’s Hospital, The Catholic University of Korea and the Korea Research Foundation (2021R1G1A1094285).

ACKNOWLEDGEMENTS

None

Table 1.

Demographic characteristics of the participants (N=110)

	Frequency (%)
Sex
Male	30 (27.3)
Female	80 (72.7)
Age (yr)
19-29	43 (39.1)
30-39	19 (17.3)
40-49	25 (22.7)
50-59	18 (16.4)
60-65	2 (1.8)
Non-response	3 (2.7)
Marital status
Single	64 (58.2)
Married	32 (29.1)
Divorced	9 (8.2)
Widowed	2 (1.8)
Non-response	3 (2.7)
Level of education
Secondary school	3 (2.7)
High school	45 (40.9)
Associate degree	20 (18.2)
Bachelor’s degree	22 (20.0)
Master’s degree	8 (7.3)
Non-response	12 (10.9)
Primary diagnosis
Depressive disorder
Major	36 (32.7)
Persistent	6 (5.5)
Unspecified	1 (0.9)
Anxiety disorder
Panic	36 (32.7)
Social	4 (3.6)
Unspecified	27 (24.5)
Comorbidity
Depressive disorder
Anxiety disorder	4 (3.6)
Others (PTSD, OCD, etc.)	8 (7.3)
Anxiety disorder
PTSD	1 (0.9)

PTSD, post-traumatic stress disorder; OCD, obsessive-compulsive disorder

Table 2.

Descriptive statistics and correlation matrix of study variables (N=110)

	1	2	3	4	5	6	7	8	9	10	11
1. Depression (PHQ-9)	-
2. Anxiety (STAI)	0.72^***	-
3. Somatization (SCL)	0.67^***	0.63^***	-
4. Cognitive reappraisal	-0.48^***	-0.62^***	-0.43^***	-
5. Expressive suppression	0.12	0.07	0.15	0.07	-
6. Notice	-0.14	-0.01	0.14	0.10	-0.01	-
7. Accept	0.10	-0.02	0.04	0.02	0.11	-0.08	-
8. Attention regulation	-0.44^***	-0.47^***	-0.39^***	0.46^***	-0.02	0.15	0.20^*	-
9. Mind-body connection awareness	-0.16^*	-0.25^**	0.02	0.28^**	0.02	0.58^***	-0.23^*	0.14	-
10. Return to body	-0.41^***	-0.49^***	-0.24^**	0.59^***	0.06	0.33^***	0.05	0.52^***	0.46^***	-
11. Trust	-0.38^***	-0.54^***	-0.29^**	0.49^***	0.03	0.24^*	0.07	0.48^***	0.36^***	0.69^***	-
Mean±SD	11.98±7.66	113.07±27.02	26.16±9.86	4.01±1.31	4.09±1.30	3.74±0.92	2.02±1.18	2.77±1.14	4.14±1.25	2.39±1.28	2.30±1.40
Skewness	0.24	-0.13	0.52	-0.18	0.04	-0.41	0.13	0.11	-0.47	0.24	0.07
Kurtosis	-1.08	-0.76	-0.85	-0.47	-0.18	-0.19	-0.82	0.11	-0.51	-0.24	-0.46

^* p<0.05;

^** p<0.01;

^*** p<0.001.

PHQ-9, Patient Health Questionnaire-9; STAI, State-Trait Anxiety Inventory; SCL, Symptom Checklist; SD, standard deviation

Table 3.

Hierarchical regression analysis for predictors of depression, anxiety and somatization (N=110)

	Mode	Predictors	B (SE)	β	t	R² (adj.R²)	ΔR²	F
Depression (PHQ-9)	1	Cognitive reappraisal	-2.87 (0.49)	-0.49	-5.89^***	0.26 (0.24)	0.26	18.38^***
	1	Expressive suppression	0.92 (0.49)	0.16	1.87	0.26 (0.24)	0.26	18.38^***
	2	Cognitive reappraisal	-1.81 (0.61)	-0.31	-2.98^**	0.35 (0.30)	0.10	2.52^*
		Expressive suppression	0.73 (0.48)	0.12	1.52
		Notice	-0.56 (0.84)	-0.07	-0.67
		Accept	1.14 (0.56)	0.18	2.05^*
		Attention regulation	-1.74 (0.68)	-0.26	-2.56^*
		Mind-body connection awareness	0.65 (0.68)	0.11	0.95
		Return to body	-0.46 (0.79)	-0.08	-0.58
		Trust	-0.47 (0.62)	-0.09	-0.76
Anxiety (STAI)	1	Cognitive reappraisal	-13.02 (1.54)	-0.63	-8.44^***	0.40 (0.39)	0.40	36.11^***
	1	Expressive suppression	2.43 (1.56)	0.12	1.55	0.40 (0.39)	0.40	36.11^***
	2	Cognitive reappraisal	-8.61 (1.86)	-0.42	-4.63^***	0.51 (0.48)	0.11	3.81^**
		Expressive suppression	2.23 (1.47)	0.11	1.52
		Notice	5.61 (2.56)	0.19	2.19^*
		Accept	0.49 (1.70)	0.02	0.29
		Attention regulation	-4.14 (2.08)	-0.17	-2.00^*
		Mind-body connection awareness	-2.86 (2.08)	-0.13	-1.37
		Return to body	0.65 (2.41)	0.03	0.27
		Trust	-5.30 (1.91)	-0.27	-2.77^**
Somatization (SCL-90-R)	1	Cognitive reappraisal	-3.36 (0.64)	-0.45	-5.24^***	0.22 (0.21)	0.22	15.29^***
	1	Expressive suppression	1.40 (0.65)	0.18	2.15^*	0.22 (0.21)	0.22	15.29^***
	2	Cognitive reappraisal	-2.64 (0.80)	-0.35	-3.31^**	0.33 (0.28)	0.11	2.72^*
		Expressive suppression	1.19 (0.63)	0.16	1.90
		Notice	1.96 (1.10)	0.18	1.79
		Accept	1.05 (0.73)	0.13	1.44
		Attention regulation	-2.29(0.89)	-0.26	-2.58^*
		Mind-body connection awareness	0.67 (0.89)	0.08	0.75
		Return to body	0.66 (1.03)	0.08	0.64
		Trust	-0.98 (0.82)	-0.14	-1.19

^* p<0.05;

^** p<0.01;

^*** p<0.001.

PHQ-9, Patient Health Questionnaire-9; STAI, State-Trait Anxiety Inventory; SCL-90-R, Symptom Checklist-90-Revised; SE, standard error

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