The Association of Emotion Regulation and Somatic Symptoms.

OBJECTIVE: People with functional somatic symptoms have difficulties in various stages of the emotion regulation (ER) process (1). As an adaptive and flexible use of ER strategies is a core tenet of emotional health, having difficulties in this area is often assumed to be the key mechanism behind functional somatic symptoms. Following a dimensional population-based sampling approach, we investigated emotion regulation abilities across a broad range of people and tested possible associations with somatic symptom reporting, habitual ER use as well as various subclinical constructs (such as alexithymia and anxiety). METHODS: In a sample of N = 254 persons, somatic symptom distress (PHQ-15, HiTOP somatoform spectrum), trait emotion regulation facets (ERQ, ERS) as well as the emotion regulation abilities (suppression and reappraisal) were assessed. Correlations (frequentist and Bayesian), ANOVAs, and Structural Equation Models were used to analyze the data. RESULTS: Correlational and SEM analyses revealed that general symptom severity (both on the somatoform HiTOP and PHQ-15) was not significantly associated with emotion regulation effectiveness, general arousal, or general valence. The sensory component of pain symptoms (r = - .708, p = .023), as well as health anxiety (r = - .443, p = .028) were significantly negatively associated with effective emotion regulation. CONCLUSIONS: Emotion regulation effectiveness appears independent of general somatic symptom distress. We make recommendations for clinical interventions in light of these complex findings.

The predictive value of cortisol in psychodynamic psychotherapy for social anxiety disorder: Extended results of the SOPHONET-Study.

Psychotherapy is an effective treatment for anxiety disorders (AD), yet a vast majority of patients do not respond to therapy, necessitating the identification of predictors to enhance outcomes. Several studies have explored the relationship between stress response and treatment outcome, as a potential treatment mechanism. However, the latter remains under-researched in patients with social anxiety disorder (SAD). We studied N = 29 patients undergoing psychodynamic psychotherapy (PDT) within the SOPHONET-Study. Stress reactivity (i.e., area under the curve with respect to the increase; AUCi) was induced by a standardized psychosocial stressor (Trier Social Stress Test; TSST) and assessed by means of adrenocorticotropic hormone (ACTH), blood and salivary cortisol samples before (t1) treatment. Samples of these biomarkers were taken -1 min prior stress exposure and six more blood samples were collected post-TSST ( + 1, + 10, + 20, + 30, + 45, + 60 min.). The participants were diagnosed with SAD based on the Structured Clinical Interview for DSM-IV (SCID) and completed the Liebowitz Social Anxiety Scale as well as the Beck Depression Inventory before (t1) and after psychotherapy (t2). Pre-treatment stress reactivity significantly predicted changes in depression (salivary p < 0.001 and blood cortisol p = 0.001), as well as in avoidance behavior (blood cortisol p = 0.001). None of the biomarkers revealed significant results in fear or in the total LSAS-scores, except for ACTH with a trend finding (p = 0.06). Regarding therapy success, symptoms of social anxiety (p = 0.005) and depression (p < 0.001) were significantly reduced from pre (t1) to post-treatment (t2). Our study showed that stress reactivity pre-treatment may serve as a predictor of psychotherapy outcome. In this regard, alterations in stress response relate to changes in symptoms of social anxiety and depression after PDT. This implies that patients with chronic stress might benefit from a targeted interventions during psychotherapy, especially to manage fear in social contexts.

Bridging the feedback implementation gap: A comparison of empirical and rational decision rules in naturalistic psychotherapy.

Objective: Previous research indicates positive effects of feedback based on rational or empirical decision rules in psychotherapy. The implementation of these usually session-to-session-based feedback systems into clinical practice, however, remains challenging. This study aims to evaluate decision rules based on routine outcome monitoring with reduced assessment frequency. Method: Data routinely collected every 5-20 sessions of N = 3758 patients treated with CBT in an outpatient clinic (Msessions = 42.8, SD = 15.4) were used to develop feedback decision rules based on the expected treatment response and nearest neighbors approach, the reliable change index, and method of percental improvement. The detection of patients at risk of treatment failure served as primary endpoint. Results: Significantly lower reliable improvement, higher reliable deterioration rates, and smaller effect sizes were found for patients identified at risk of treatment failure by all rules. The nearest neighbors-based approach showed the highest sensitivity regarding the detection of reliably deteriorated cases. Conclusion: Consistent with previous research, the empirical models outperformed the rational rules. Still, the first-time used percental improvement-based rule also showed satisfactory results. Overall, the results point to the potential of basic feedback systems that might be easier to implement in practice than session-to-session based systems.

Somatic symptom distress is not related to cardioceptive accuracy.

OBJECTIVE: (Cardiac) interoception was long considered a key mechanism behind symptom perception in persistent somatic symptoms (PSS). In this study, we aimed to extend earlier findings to clarify this potential interoceptive mechanisms of PSS. METHODS: A cross-sectional sample of 251 participants (23.1% with self-reported functional somatic syndrome) completed a laboratory study with two cardioceptive accuracy tasks (Schandry task and a new cardiac signal detection task) and multiple questionnaires. Somatic symptom distress and associated constructs were assessed with the PHQ-15, as well as with a novel multidimensional questionnaire measure (HiTOP-SF1) derived from the somatoform spectrum of the Hierarchical Taxonomy of Psychopathology (HiTOP). Correlations (frequentist and Bayesian) and structural equation modelling (SEM) helped further investigate the interplay between these variables. RESULTS: There were no significant correlations between measures of interoception and somatic symptom distress. Self-report and behavioral cardioceptive accuracy measures did not correlate significantly. No significant covariances emerged between diagnostic tools and cardioceptive accuracy; Bayesian analyses supported the lack of association between interoception and symptom perception. CONCLUSIONS: Cardiac interoception (specifically cardioceptive accuracy) unlikely represents a key mechanism in PSS etiology. We recommend investigating other factors in PSS.

"And how did that make you feel?" - Repeated symptom queries enhance symptom reports elicited by negative affect.

OBJECTIVE: Negative affect, alexithymia, and other predisposing traits (such as health anxiety) can influence an individual's symptom perception. In this study, we used the affective picture paradigm (APP, Bogaerts et al., 2010) to induce symptoms using affective picture stimuli. We aimed to cross-sectionally test the effect of high vs low-frequency symptom queries and analyze the time course of the APP, including interactions with health anxiety and somatic symptom distress. METHODS: Participants (N = 124) completed a modified APP and filled out various questionnaires. In the APP, participants were randomized to either a highly-frequent-query condition (18 symptom checklists) or a less-frequent-query condition (6 checklists). Data were analyzed using ANOVAs, cross-lagged panel models, moderation models, and multilevel models. RESULTS: Both groups had comparable symptom baseline values, but people in the highly frequent as opposed to less frequent condition reported significantly higher symptom levels once the experiment started (F (1,120) = 14.319, p < .001, η2=.107). Symptom levels stayed stable over the course of the experiment and were best predicted by symptom levels at earlier timepoints in the experiment (ß = 0.43 and ß = 0.68, both p < .001). Health anxiety levels significantly predicted symptom levels (F(1,121) = 10.054, p = .002, η2=.077) and moderated the relation between condition and symptom levels (F(2,121) = 16.253, p < .001, η2=.212). CONCLUSION: In terms of the predictive processing model (e.g.,[1]), repeated symptom queries following negative affective cues may activate prior beliefs about symptoms, resulting in elevated levels of symptom reports in interaction with health anxiety.

He Who Seeks Finds (Bodily Signals): German Validation of the Interoceptive Attention Scale (IATS) and its Relationship with Subclinical Psychopathology.

Alterations in interoception have been linked to psychopathology. Recent findings suggest that both the attention to and the accuracy of, interoceptive perceptions may be oppositely related to subclinical symptomatology. Thus, providing well-validated tools that tap into these interoceptive processes is crucial for understanding the relation between interoceptive processing and subclinical psychopathology. In the current study (N = 642), we aimed to (1) validate the German version of the Interoceptive Attention Scale (IATS; Gabriele et al., 2022), and (2) test the differential association of self-reported interoceptive attention and accuracy with subclinical symptomatology, including alexithymia, depressive, and anxious symptomatology. We observed that a one-factor solution is a well-fitting model for the IATS. Further, the IATS showed good internal consistency, convergent, and divergent validity, but poor test-retest reliability. Self-reported interoceptive attention and accuracy were unrelated to each other. However, IATS scores were positively related to all measures of psychopathology (except depressive symptomatology), whereas self-reported interoceptive accuracy scores showed negative or nonsignificant relations with these. Our data suggest that the IATS is a good instrument to measure self-report interoceptive attention in the German population. Further, we highlight the need to distinguish between constructs of interoception to better understand the relation between interoception and psychopathology.

EFFects of Exposure and Cognitive behavioral Therapy for chronic BACK pain ("EFFECT-BACK"): study protocol for a randomized controlled trial.

INTRODUCTION: Chronic back pain is a widespread medical condition associated with high socioeconomic costs and increasing prevalence. Despite the advanced implementation of multidisciplinary approaches, providing a satisfactory treatment offer for those affected is often not possible. Exposure therapy (EXP) promises to be an effective and economical form of treatment and in a previous pilot study showed to be superior to cognitive behavioral therapy (CBT) in reducing perceived limitations of movement. The current study aims to further compare the efficacy of both treatment methods and identify those patient groups that particularly benefit from EXP. METHODS: The general objective of this randomized multicenter clinical trial (targeted N = 380) is to improve and expand the range of treatments available to patients with chronic back pain. As the primary objective of the study, two different psychological treatments (EXP and CBT) will be compared. The primary outcome measure is a clinically significant improvement in pain-related impairment, measured by the QPBDS, from baseline to 6-month follow-up. Secondary outcome measures are absolute changes and clinically significant improvements in variables coping, psychological flexibility, depressiveness, catastrophizing, exercise avoidance and fear of exercise, and intensity of pain. Participants are recruited in five psychological and medical centers in Germany and receive ten sessions of manualized therapy by trained licensed CBT therapists or clinical psychologists, who are currently in their post-gradual CBT training. Potential predictors of each treatment's efficacy will be explored with a focus on avoidance and coping behavior. CONCLUSION: This study will be the first RCT to compare CBT and EXP in chronic back pain in a large sample, including patients from different care structures due to psychological and medical recruitment centers. By identifying and exploring potential predictors of symptom improvement in each treatment group, this study will contribute to enable a more individualized assignment to treatment modalities and thus improves the care situation for chronic back pain and helps to create a customized treatment program for subgroups of pain patients. If our findings confirm EXP to be an efficacious and efficient treatment concept, it should gain more attention and be further disseminated. TRIAL REGISTRATION: ClinicalTrials.gov NCT05294081. Registered on 02 March 2022.

Efficacy of internet-based psychological interventions for pathological health anxiety: A three-level meta-analysis of randomized controlled trials.

OBJECTIVE: This study aimed to provide a comprehensive summary and synthesis of available evidence on the efficacy of internet-based psychological interventions for pathological health anxiety, as well as to examine the variables that possibly moderate intervention effects. METHOD: Four databases were searched for the literature up to October 2023. A three-level random-effects model was used to estimate the pooled effect size, with Hedge's g as the measure. RESULTS: We extracted 28 effect sizes from nine eligible randomized controlled trials with 1079 participants. The results showed that internet-based psychological interventions had a moderate to large between-group effect on health anxiety (g = 0.70) that was significant both at post-intervention (g = 0.74) and follow-up (g = 0.64). Furthermore, these interventions were significantly more effective than passive control conditions including waitlist, usual care, and placebo at post-treatment (g = 1.07), but had effects comparable to active control groups at both post-intervention and follow-up. CONCLUSIONS: Internet-based psychological interventions are an effective way to alleviate pathological health anxiety. We recommend that these interventions be more widely implemented in routine care settings to ensure easy accessibility for patients with health anxiety.

"The early bird catches the worm"-Prediction of early response and its importance for treatment outcome in a naturalistic setting of cognitive behaviour therapy.

OBJECTIVE: Knowledge about predictors of early response (ER) remains limited. This study examined patient, process, and therapist variables to predict ER in a naturalistic setting. RESEARCH DESIGN AND METHODS: Data from 493 psychotherapy outpatients were analysed. ER was defined by a ≥25% reduction in general psychological distress (ER percent) and by the reliable change index (ER RCI) within the first 10 sessions measured by the Brief Symptom Inventory-18. ER prediction was determined using logistic regression. General psychological distress (GSI) throughout treatment in patients with and without ER was modelled using a multilevel linear model. This model aimed to predict GSI over treatment using repeated measurements, considering group affiliation (ER percent vs. no ER percent), controlled for other predictors. RESULTS: The prevalence of ER percent and ER RCI were 63.6% and 47.5%, respectively. GSI and therapeutic relationship significantly predicted ER (ER percent: χ2 (6) 70.32, p < .001, Nagelkerkes R2 = .19; ER RCI: χ2 (6) 134.71, p < .001, Nagelkerkes R2 = .35). Patients who rated the therapeutic relationship more positively were more likely to achieve ER (OR = 1.10). Difference in outcomes between patients with and without ER during treatment was influenced by factors such as therapeutic relationship, GSI, therapist experience, and mental comorbidities. Including these variables improved the predictive model from AIC = 17,042.98 to AIC = 16,730.24. CONCLUSION: The therapeutic relationship is a crucial predictor of ER. Patients achieving ER tend to have better outcome than those without ER. The early phase of therapy warrants particular attention to enhance psychotherapy outcomes.

Illustrating the pathway from affect to somatic symptom: the Affective Picture Paradigm.

High levels of somatic symptom distress represent a core component of both mental and physical illness. The exact aetiology and pathogenesis of this transdiagnostic phenomenon remain largely unknown. The Affective Picture Paradigm (APP) represents an innovative experimental paradigm to study somatic symptom distress. Based on the HiTOP framework and a population-based sampling approach, associations between facets of somatic symptom distress and symptoms induced by the APP were explored in two studies (N1 = 201; N2 = 254) using structural equation bi-factor models. Results showed that the APP effect was significantly positively correlated with general somatic symptom distress (PHQ-15, HiTOP), cardio-respiratory symptoms (PHQ-15), as well as difficulties identifying feelings. In conclusion, negative affective cues in the APP can elicit somatic symptoms, particularly in people with higher levels of somatic symptom distress. Difficulties identifying feelings might contribute to this phenomenon. Results are compatible with a predictive processing account of somatic symptom perception.

Is cyberchondria specific to hypochondriasis?

Cyberchondria (i.e., excessive health-related Internet search linked to psychological distress) is usually associated with health anxiety, but relationships with other psychopathological symptoms were also found. However, studies are lacking in patients with hypochondriasis, and it remains unclear whether cyberchondria and its subfacets are specific to hypochondriasis (i.e., higher levels in hypochondriasis compared to other mental disorders). Patients with hypochondriasis (N = 50), a clinical (N = 70), and a healthy comparison group (N = 51) completed two questionnaires on cyberchondria whose combined 17 subscales were reduced to three relevant cyberchondria subfacets by second-order factor analysis. The cyberchondria subfacet emotional distress/negative consequences linked to health-related Internet searches showed significantly higher scores in patients with hypochondriasis than in the two comparison groups (d ≥ 1.7) and was the only predictor of dimensional health anxiety (ß = .58, p ≤ .001). The two subfacets type/extent of health-related Internet searches and characteristics of the Internet (e.g., attitude toward unreliability, vast amounts of information) were less specifically associated with hypochondriasis. The results are consistent with models of cyberchondria and hypochondriasis, particularly on the anxiety-reinforcing vicious circle and maintaining factors. Based on the findings, practical implications are discussed.

Further Evidence for a Dimensional Latent Structure of Health Anxiety: Taxometric Analyses of the Whiteley Index Based on Two German Representative Samples.

Health anxiety is an intricate part of illness anxiety and somatic symptom disorder. Based on convenience samples, two out of three available studies indicate that it is a dimensional rather than a categorical construct. Using two representative datasets, this study investigates whether previous results can be clarified. Conventional taxometric analyses as well as comparison curve fit indices (CCFI) profile analyses (MAMBAC and MAXSLOPE procedures) were calculated with two datasets of the German adult population assessing the Whiteley Index (WI-14, N = 2,072; WI-7, N = 2,498). Mean CCFIs indicated a dimensional structure for both the WI-7 (mean CCFI = 0.42, mean CCFI profile = 0.40) and the WI-14 (mean CCFI = 0.44, mean CCFI profile = 0.32). The results support and extend previous findings by strongly suggesting a dimensional distribution of health anxiety in the general population. Implications for research and practice comprise the adoption of a dimensional description of psychopathology as well as transdiagnostic treatment approaches.

Cognitive-behavioral therapy for patients with post-COVID-19 condition (CBT-PCC): a feasibility trial.

BACKGROUND: The post-COVID-19 condition describes the persistence or onset of somatic symptoms (e.g. fatigue) after acute COVID-19. Based on an existing cognitive-behavioral treatment protocol, we developed a specialized group intervention for individuals with post-COVID-19 condition. The present study examines the feasibility, acceptance, and effectiveness of the program for inpatients in a neurological rehabilitation setting. METHODS: The treatment program comprises eight sessions and includes psychoeducational and experience-based interventions on common psychophysiological mechanisms of persistent somatic symptoms. A feasibility trial was conducted using a one-group design in a naturalistic setting. N = 64 inpatients with a history of mild COVID-19 that fulfilled WHO criteria for post-COVID-19 condition were enrolled. After each session, evaluation forms were completed and psychometric questionnaires on somatic and psychopathological symptom burden were collected pre- and post-intervention. RESULTS: The treatment program was well received by participants and therapists. Each session was rated as comprehensible and overall satisfaction with the sessions was high. Pre-post effect sizes (of standard rehabilitation incl. new treatment program; intention-to-treat) showed significantly reduced subjective fatigue (p < 0.05, dav = 0.33) and improved disease coping (ps < 0.05, dav = 0.33-0.49). CONCLUSIONS: Our results support the feasibility and acceptance of the newly developed cognitive-behavioral group intervention for individuals with post-COVID-19 condition. Yet, findings have to be interpreted cautiously due to the lack of a control group and follow-up measurement, the small sample size, and a relatively high drop-out rate.

Somatic Symptom Disorder and Health Anxiety: Assessment and Management.

The fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) Somatic Symptom Disorder (SSD) and Illness Anxiety Disorder (IAD) replaced the diagnostic entities of the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) somatoform disorders and hypochondriasis. SSD turns away from specifying the presence or absence of a medical condition for presented symptoms and instead focuses on excessive symptom-related affects, cognitions, and behaviors. People with pathological health anxiety can be diagnosed with SSD or IAD, depending on the intensity of accompanying somatic symptoms. Cognitive-behavioral therapy shows the best empirical evidence for an effective treatment of SSD and IAD.

Somatic symptom distress and ICD-11 prolonged grief in a large intercultural sample.

Background: Grief is a multi-faceted experience including emotional, social, and physical reactions. Research in ICD-11 prolonged grief disorder (PGD) in different cultural contexts has revealed different or potentially missing grief symptoms that may be relevant.Objective: This study thus aimed to explore the prevalence of somatic symptom distress and its associations with grief and negative affect in a culturally diverse sample of bereaved individuals with symptoms of PGD.Methods: Based on cross-sectional survey data from the Measurement and Assessment of Grief (MAGIC) project, this study included 1337 participants (mean age 23.79 yrs, 76.1% female) from three regions (USA: 62.3%, Turkey/Iran: 24.2%, Cyprus/Greece: 13.5%), who experienced a loss of a significant other. Associations between somatic symptom distress (Somatic Symptom Scale, SSS-8), symptoms of PGD (International Prolonged Grief Disorder Scale, IPGDS-33), anxiety (Generalized Anxiety Disorder Questionnaire, GAD-7), depression (Patient Health Questionnaire, PHQ-9) as well as demographic and loss related characteristics were investigated. Three hundred and thirteen participants (23.4%) scored above the proposed cut-off for clinically severe PGD.Results: 'High' or 'very high' levels of somatic symptom distress were more frequent in a possible PGD group (58.2%), than in a non-PGD group (22.4%), p < .001, as divided per cut-off in the IPGDS. In a multiple regression analysis, PGD symptoms were significantly but weakly associated with somatic symptom distress (ß = 0.08, p < .001) beyond demographics, loss-related variables, and negative affect. Negative affect (anxiety and depression) mediated the relationship of PGD symptoms with somatic symptom distress and the indirect effect explained 58% of the variance.Conclusions: High levels of somatic symptom distress can be observed in a substantial proportion of bereaved across cultures. Our findings suggest that PGD is related to somatic symptom distress partly and indirectly through facets of negative affect.

30.8% of bereaved adults showed 'high' or 'very high' levels of somatic symptom distress.Anxiety and depression partially mediate relationship of PGD symptoms with somatic symptom distress.Findings encourage practitioners to consider somatic symptom distress in psychotherapeutic treatment of PGD.

Respiratory Interoception and Pathological Illness Anxiety: Disentangling Bias.

OBJECTIVE: Biased interoception decoupled from physiology might be relevant in the etiology of pathological illness anxiety (PIA). Empirical evidence for interoceptive deviations in illness anxiety is scarce but potentially informative to optimize treatments. We hypothesized that persons with PIA differ fundamentally in the classification of bodily sensations from those without PIA. METHODS: In a respiratory categorization task, participants breathed into a pulmonary training device. Inspiration effort was varied by eight resistive loads. The lower/higher four loads were introduced as belonging to arbitrary categories "A"/"B," respectively. Participants memorized respiratory sensations in a first experimental block and were asked to label the resistances in a second block. We calculated the sensitivity of resistance classification according to category and response bias in terms of categorical misclassification. Data of 39 participants with PIA and 35 controls were compared with regard to sensitivity and response bias by group, resistive load, and their interaction in a multiple regression. RESULTS: With similar sensitivity, patients more often labeled loads above the categorical border erroneously as belonging to category A, thus underestimating their resistance ( ß = -0.06, p = .001; η2 = 0.02). CONCLUSIONS: Individuals with PIA showed a systematic "wait and see" approach. Altered respiroception in PIA might stem from biased perception during training phase, the recognition phase, biased memory, or a combination of these. Its exact characteristics remain unknown, and future research must address the challenge of developing reliable and valid paradigms accounting for the variability of interoceptive biases. REGISTRATION: This work was preregistered on OSF ( https://osf.io/9shcw ).

Is the rubber hand illusion associated with somatic symptom reporting?

Current approaches to somatic symptom perception conceptualize somatic symptoms partly as somato-visceral or body illusions evoked by an interaction between bottom-up (sensory) and top-down (expectations, attention) processes. Similar processes of multisensory integration are assumed to contribute to the rubber hand illusion (RHI). Findings concerning the strength and direction of associations between these two phenomena, symptom perception and the RHI, are equivocal. Individuals of a non-clinical sample (N = 63; 56% females; Mage = 20.4; SD = 1.6) completed the Patient Health Questionnaire Somatic Symptom Scale (PHQ-15) and participated in an experiment that evoked the RHI. In repeated measures analyses of variance with the PHQ-15 score as covariate, no significant interaction effects between the PHQ-15 score and indicators of the RHI, i.e., proprioceptive drift (F(1,61) < 0.001 p = 0.993, partial η2 < 0.001; BF10 = 0.307), felt body ownership(F(1,59) = 0.043, p = 0.836, partial η2 = 0,001; BF10 = 0.501), and felt body disownership (F(1,59) = 0.148, p = 0.702, partial η2 = 0.002; BF10 = 1.972) were found. Overall, frequentist and Bayesian analysis indicated that the support for a possible association between the PHQ-15 and indicators of the RHI remains inconclusive, i.e., neither the null nor the alternative hypotheses were sufficiently supported. At least in this non-clinical sample, the association between somatic symptom distress and the strength of the RHI appears so weak (perhaps non-existing), that both phenomena (somatic symptom distress and the RHI) appear distinct and largely unrelated.

Emotion dynamics and somatic symptoms in everyday life: Ecological momentary assessment in somatic symptom disorder and healthy controls.

OBJECTIVE: Negative affectivity (NA) is associated with the emergence and persistence of physical symptoms with unclear organic pathology. This study investigated the temporal dynamics of NA and somatic symptom burden using ecological momentary assessment (EMA) in adults with somatic symptom disorder (SSD) and healthy control participants (HC). METHODS: Participants underwent a seven-day, smartphone-based EMA, with 6 randomly-stratified time points per day. NA was assessed using a five-item short form of the Positive and Negative Affectivity Scale (PANAS) and somatic symptom burden with two self-constructed items. 22 persons with SSD and 20 HCs were included in multilevel analyses. RESULTS: Within-person analyses showed a significantly stronger (positive) association of concurrent NA with somatic symptom burden in participants with SSD than in HCs, ß = 0.15, SE = 0.04, p = .001. Time-lagged analyses demonstrated that, across groups, NA at a previous time point t-1 significantly predicted somatic symptom burden at the subsequent timepoint t, ß = 0.09, SE = 0.03, p = .005, but not in the other direction (somatic symptom burdent-1→ NAt, ß = 0.01, SE = 0.04, p = .79). Between-person analyses showed that both inertia (i.e., persistence of negative affective states), d = 0.74, and instability (i.e., magnitude of moment-to-moment fluctuations), d = 0.76 of NA were significantly higher in participants with SSD than in HCs. CONCLUSIONS: Our findings sustain the idea of (negative) affect-driven modulation in somatic signal processing and suggest that interoceptive and emotional differentiation training can advance the psychotherapeutic treatment of SSD.