Emotional Awareness and Expression Therapy vs Cognitive Behavioral Therapy for Chronic Pain in Older Veterans: A Randomized Clinical Trial

Importance

Chronic pain is common and disabling in older adults, and psychological interventions are indicated. However, the gold standard approach, cognitive-behavioral therapy (CBT), produces only modest benefits, and more powerful options are needed.

Objectives

To evaluate whether emotional awareness and expression therapy (EAET) is superior to CBT for treatment of chronic pain among predominantly male older veterans and whether higher baseline depression, anxiety, or posttraumatic stress disorder (PTSD) symptoms-key targets of EAET-moderate treatment response.

Design, Setting, and Participants

This 2-arm randomized clinical trial was conducted from May 16, 2019, to September 14, 2023, in the US Department of Veterans Affairs Greater Los Angeles Healthcare System. The trial included a racially and ethnically diverse group of veterans aged 60 to 95 years with at least 3 months of musculoskeletal pain.

Interventions

Emotional awareness and expression therapy or CBT, conducted concurrently, each presented as one 90-minute individual session followed by eight 90-minute group sessions.

Main Outcomes and Measures

The primary outcome was Brief Pain Inventory pain severity (range, 0 to 10) from baseline to posttreatment (week 10, primary end point) and 6-month follow-up. Secondary outcomes included Patient Reported Outcomes Institute Measurement System Anxiety, Depression, Fatigue, General Life Satisfaction (NIH Toolbox), Pain Interference, and Sleep Disturbance Short Forms, Patient Global Impression of Change (PGIC), and Satisfaction with Therapy and Therapist Scale-Revised. A subset of participants completed the PTSD Checklist for Diagnostic and Statistical Manual of Mental Disorders (Fifth Edition). All analyses were for the intention-to-treat population and included all randomized participants.

Results

Among 126 randomized participants (66 in the EAET group and 60 in the CBT group; mean [SD] age, 71.9 [5.9] years; 116 [92%] male), 111 (88%) completed posttreatment, and 104 (82%) completed the 6-month follow-up. The EAET was superior to CBT for the primary outcome of reduction in pain severity at posttreatment (estimate, -1.59 [95% CI, -2.35 to -0.83]; P < .001) and follow-up (estimate, -1.01 [95% CI, -1.78 to -0.24]; P = .01). A greater percentage of participants in EAET vs CBT had clinically significant (at least 30%) pain reduction (63% vs 17%; odds ratio, 21.54 [95% CI, 4.66-99.56]; P < .001) at posttreatment. In addition, EAET was superior to CBT on 50% pain reduction (35% vs 7%; odds ratio, 11.77 [95% CI, 2.38-58.25]; P = .002), anxiety (estimate, -2.49 [95% CI, -4.30 to -0.68]; P = .006), depression (estimate, -3.06 [95% CI, -5.88 to -0.25]; P = .03), general life satisfaction (estimate, 1.23 [95% CI, 0.36-2.10]; P = .005), PTSD symptoms (estimate, -4.39 [95% CI, -8.44 to -0.34]; P = .03), PGIC score (estimate, 1.46 [95% CI, 0.77-2.15]; P < .001), and global treatment satisfaction (estimate, 0.28 [95% CI, 0.12-0.45]; P < .001) at posttreatment. Higher baseline depression (estimate, -1.55 [95% CI, -0.37 to 2.73]; P < .001), anxiety (estimate, -1.53 [95% CI, -2.19 to -0.88]; P < .001), and PTSD symptoms (estimate, -1.69 [95% CI, -2.96 to -0.42]; P = .009) moderated greater reduction in pain severity after EAET but not CBT.

Conclusions and Relevance

The results of this randomized clinical trial suggest that EAET may be a preferred intervention for medically and psychiatrically complex patients with pain. The societal burden of chronic pain could be improved by further incorporating the principles of EAET into mainstream clinical pain medicine.

Trial Registration

ClinicalTrials.gov Identifier: NCT03918642.

[Emotional competence of patients with chronic pain : A self- and third-party assessment]

RESEARCH QUESTION

The aim of the study is to assess the status quo of emotional competence in people with chronic pain. How do patients experience themselves regarding to their ability to perceive, express, and regulate emotions? And does this assessment coincide with the assessment of emotional competence (EC) by mental health professionals?

METHODS

The study took place in the context of interdisciplinary multimodal pain therapy at an outpatient clinic in N = 184 adult German-speaking individuals with non-cancer-related chronic pain. EC was assessed at the end of therapy using the self- and third-party assessment scales of the Emotional Competence Questionnaire. The external assessment was performed by the mental health team. Standard scores were created using the norm sample provided by questionnaires. These were analyzed descriptively and inferentially.

RESULTS

Self-perceived EC was average (Mself_total = 99.31; SD = 7.78). The mental health professionals predominantly rated the emotional competence of the patients significantly lower (Mexternal_total = 94,70; SD = 7,81; F(1.179) = 35,73; p < 0.001; η2 = 0.17). Emotional expressivity, as a component of EC, was externally rated as below average (Mexpressivity_external = 89.14, SD = 10.33).

DISCUSSION

Patients with chronic pain rate themselves as unimpaired in terms of their daily emotional awareness, expression, and regulation abilities. At the same time, mental health professionals rate these same individuals as significantly less emotionally competent. The question remains open as to what extent the divergent assessments can be explained by assessment bias.

Emotion regulation skills-focused interventions for chronic pain: A systematic review and meta-analysis

OBJECTIVES

To investigate the effect of emotion regulation skills-focused (ERSF) interventions to reduce pain intensity and improve psychological outcomes for people with chronic pain and to narratively report on safety and intervention compliance.

METHODS

Six databases and four registries were searched for randomized controlled trials (RCTs) up to 29 April 2022. Risk of bias was evaluated using the Cochrane RoB 2.0 tool, and certainty of evidence was assessed according to the Grading, Assessment, Development and Evaluation (GRADE). Meta-analyses for eight studies (902 participants) assessed pain intensity (primary outcome), emotion regulation, affect, symptoms of depression and anxiety, and pain interference (secondary outcomes), at two time points when available, post-intervention (closest to intervention end) and follow-up (the first measurement after the post-intervention assessment).

RESULTS

Compared to TAU, pain intensity improved post-intervention (weighted mean difference [WMD] = -10.86; 95% confidence interval [CI] [-17.55, -2.56]) and at follow-up (WMD = -11.38; 95% CI [-13.55, -9.21]). Emotion regulation improved post-intervention (standard mean difference [SMD] = 0.57; 95% CI [0.14, 1.01]), and depressive symptoms improved at follow-up (SMD = -0.45; 95% CI [-0.66, -0.24]). Compared to active comparators, anxiety symptoms improved favouring the comparator post-intervention (SMD = 0.10; 95% CI [0.03, 0.18]), and compared to CBT, pain interference improved post-intervention (SMD = -0.37; 95% CI [-0.69, -0.04]). Certainty of evidence ranged from very low to moderate.

SIGNIFICANCE

The findings provide evidence that ERSF interventions reduce pain intensity for people with chronic pain compared to usual treatment. These interventions are at least as beneficial to reduce pain intensity as the current gold standard psychological intervention, CBT. However, the limited number of studies and certainty of evidence mean further high-quality RCTs are warranted. Additionally, further research is needed to identify whether ERSF interventions may be more beneficial for specific chronic pain conditions.

The effects of virtual reality neuroscience-based therapy on clinical and neuroimaging outcomes in patients with chronic back pain: a randomized clinical trial

ABSTRACT

Chronic pain remains poorly managed. The integration of immersive technologies (ie, virtual reality [VR]) with neuroscience-based principles may provide effective pain treatment by targeting cognitive and affective neural processes that maintain pain and therefore potentially changing neurobiological circuits associated with pain chronification and amplification. We tested the effectiveness of a novel VR neuroscience-based therapy (VRNT) to improve pain-related outcomes in n = 31 participants with chronic back pain, evaluated against usual care (waitlist control; n = 30) in a 2-arm randomized clinical trial (NCT04468074). We also conducted pre-treatment and post-treatment MRI to test whether VRNT affects brain networks previously linked to chronic pain and treatment effects. Compared with the control condition, VRNT led to significantly reduced pain intensity (g = 0.63) and pain interference (g = 0.84) at post-treatment vs pre-treatment, with effects persisting at 2-week follow-up. These improvements were partially mediated by reduced kinesiophobia and pain catastrophizing. Several secondary clinical outcomes were also improved by VRNT, including disability, quality of life, sleep, and fatigue. In addition, VRNT was associated with increases in dorsomedial prefrontal functional connectivity with the superior somatomotor, anterior prefrontal and visual cortices, and decreased white matter fractional anisotropy in the corpus callosum adjacent to the anterior cingulate, relative to the control condition. Thus, VRNT showed preliminary efficacy in significantly reducing pain and improving overall functioning, possibly through changes in somatosensory and prefrontal brain networks.

Application of a Clinical Approach to Diagnosing Primary Pain: Prevalence and Correlates of Primary Back and Neck Pain in a Community Physiatry Clinic

Chronic back or neck pain (CBNP) can be primary (nociplastic or neuroplastic; without clear peripheral etiology) or secondary (to nociceptive or neuropathic causes). Expanding on available models of nociplastic pain, we developed a clinic-ready approach to diagnose primary/nociplastic pain: first, a standard physical exam and review of imaging to rule out secondary pain; and second, a detailed history of symptom presentation to rule in primary pain. We trained a physician who evaluated 222 patients (73.9% female, age M = 59.6) with CBNP; patients separately completed pain and psychosocial questionnaires. We estimated the prevalence of primary CBNP and explored biomedical, imaging, and psychological correlates of primary CBNP. Although almost all patients (97.7%) had at least 1 spinal anomaly on imaging, the diagnostic approach estimated that 88.3% of patients had primary pain, 5.0% had secondary pain, and 6.8% had mixed pain. Patients with primary pain were more likely than the other 2 groups of patients (combined as "non-primary pain") to report certain functional conditions, central sensitization, and features such as sensitivity to light touch, spreading pain, and pain worsening with stress; however, no difference was detected in depression, anxiety, and pain catastrophizing between those with primary and nonprimary pain. These findings are consistent with prior estimates that 85 to 90% of CBNP is "nonspecific." Further research is needed to validate and perhaps refine this diagnostic approach, which holds the potential for better outcomes if patients are offered treatments targeted to primary pain, such as pain neuroscience education and several emerging psychological therapies. PERSPECTIVE: We developed an approach to diagnose chronic primary pain, which was applied in a physiatry clinic to 222 patients with CBNP. Most patients (88.3%) had primary pain, despite almost universal anomalies on spinal imaging. This diagnostic approach can guide educational and psychological treatments tailored for primary pain.

Mapping review of pain management programmes and psychological therapies for community-dwelling older people living with pain

PURPOSE

Persistent pain is common in older people and people living with frailty. Pain or the impact of pain on everyday life is potentially modifiable. We sought to map research evidence and information from randomised controlled trials (RCTs) of pain management programmes and psychological therapies targeting community-dwelling older people, and explore appropriate strategies and interventions for managing or reducing the negative impact of pain for older people, particularly those with frailty.

METHOD

A mapping review of pain management programmes and psychological therapies for community-dwelling older people living with chronic pain. We searched for systematic reviews of randomised controlled trials and for individual randomised controlled trials and extracted data from eligible studies.

RESULTS

Searches resulted in 3419 systematic review records and 746 RCT records from which there were 33 eligible interventions identified in 31 eligible RCTs (48 reports). Broad aims of the interventions were to: improve physical, psychological, or social functioning; adjust the effects or sensation of pain psychologically; enhance self-care with self-management skills or knowledge. Common mechanisms of change proposed were self-efficacy enhanced by self-management tasks and skills, using positive psychological skills or refocusing attention to improve responses to pain, and practising physical exercises to improve physiological well-being and reduce restrictions from pain. Content of interventions included: skills training and activity management, education, and physical exercise. Interventions were delivered in person or remotely to individuals or in groups, typically in 1-2 sessions weekly over 5-12 weeks.

CONCLUSION

All the evaluated interventions appeared to show potential to provide some benefits to older people. None of the included studies assessed frailty. However, some of the included interventions appear appropriate for community-dwelling older people living with both frailty and pain.

Emotion-Focused Psychodynamic Interview for People with Chronic Musculoskeletal Pain and Childhood Adversity: A Randomized Controlled Trial

Childhood adversity and emotional conflicts are associated with the presence and severity of chronic musculoskeletal pain (CMP), yet common treatments for CMP do not address such risk factors. We developed a single session, emotion-focused psychodynamic interview, based on Emotional Awareness and Expression Therapy and Intensive Short-term Psychodynamic Therapy, and we tested the interview's effects on pain-related outcomes and potential psychological mediators in a randomized, controlled trial. Adults (N = 91; ages 21-70, M = 44.64; 87.9% women) reporting CMP and at least 3 adverse childhood experiences completed measures at baseline and 6-week follow-up. Participants were randomized to immediate interview or waitlist control conditions. The 90-minute interview was conducted via videoconference, and the interviewer elicited disclosure of adversities and conflicts, linked these with pain, and encouraged the experience and expression of adaptive emotions. Analyses indicated that conditions did not differ significantly on change in pain severity; however, compared to control, the interview led to a significantly greater reduction in pain interference (P = .016, ηp2 = .05) and a similar trend for anxiety (P = .058, ηp2 = .04). The interview also significantly changed several potential mediators: pain-related anxiety (P = .008, ηp2 = .06), pain controllability (P = .016, ηp2 = .06), and psychological (P < .001, ηp2 = .15) and brain attributions (P = .022, ηp2 = .05) for pain. Participants viewed the interview as very valuable. We conclude that addressing childhood adversities and conflicts in a psychodynamic interview is beneficial for people with CMP. PERSPECTIVE: This study found that, compared to waitlist control, a 90-minute, remotely-administered, emotion-focused, psychodynamic interview improved pain interference, and anxiety among adults with chronic musculoskeletal pain and childhood adversity. Intensive emotional work can be done in a single session to the benefit of patients with chronic musculoskeletal pain.

Video telehealth emotional awareness and expression therapy for older U.S. military veterans with chronic pain: A pilot study

OBJECTIVES

Emotional Awareness and Expression Therapy (EAET) targets trauma and emotional conflict to reduce or eliminate chronic pain, but video telehealth administration is untested. This uncontrolled pilot assessed acceptability, feasibility, and preliminary efficacy of group-based video telehealth EAET (vEAET) for older veterans with chronic musculoskeletal pain.

METHODS

Twenty veterans were screened, and 16 initiated vEAET, delivered as one 60-minute individual session and eight 90-minute group sessions. Veterans completed posttreatment satisfaction ratings and pain severity (primary outcome), pain interference, anxiety, depression, functioning, social connectedness, shame, and anger questionnaires at baseline, posttreatment, and 2-month follow-up.

RESULTS

Satisfaction was high, and veterans attended 7.4 (SD = 0.6) of 8 group sessions; none discontinued treatment. Veterans attained significant, large reductions in pain severity from baseline to posttreatment (p < .001, Hedges' g = -1.54) and follow-up (p < .001, g = -1.20); 14 of 16 achieved clinically significant (≥ 30%) pain reduction, and 3 achieved 90-100% pain reduction. Secondary outcomes demonstrated significant, medium-to-large improvements.

CONCLUSIONS

In this small sample, vEAET produced better attendance, similar benefits, and fewer dropouts than in-person EAET in prior studies. Larger, controlled trials are needed.

CLINICAL IMPLICATIONS

Group vEAET appears feasible and highly effective for older veterans with chronic pain.

Emotional Awareness and Expression Interview: Examining Interview Content and Patient Experiences in Two Medical Samples

A single session of Emotional Awareness and Expression Therapy (EAET)-the EAET Interview-was previously shown to lead to clinical benefits for patients with centralized somatic conditions in primary care (Ziadni et al. in Health Psychol 37(3):282-290, 2018) and tertiary care (Carty et al. in Pain Med 20(7):1321-1329, 2019) settings. There has yet to be an examination of patients' experiences of and reactions to the EAET Interview, which is crucial in evaluating possible clinical implementation of the interview. We conducted secondary analyses on 88 patients (M age = 41.32, 90.9% women) from the two prior trials (primary care N = 51; tertiary care N = 37). Analyses examined interview processes (stress disclosure themes, working alliance, and emotional processing) and patients' reactions to the interview (interview credibility and perceived value of the interview), comparing the two samples and examining correlations among these variables. All patients disclosed at least one stressful life experience, commonly interpersonal problems (89.2%) and childhood adversity (51.5%). Patients had moderately high levels of working alliance and emotional processing during the interview and reported high interview credibility and perceived value of the interview. More extensive emotional processing of stressors was associated with more positive patient reactions to the interview, including higher interview credibility (r = .23) and perceived value (r = .32). We conclude that the single-session EAET Interview was valued by most patients, and patients' emotional processing is particularly beneficial. Addressing the trauma and emotional conflicts of patients with centralized somatic conditions is both feasible and valuable in front-line medical settings.

Understanding the gaps in headache and migraine treatment with psychological and behavioral interventions: A narrative review

OBJECTIVE

In this narrative review, we summarize relevant literature pertaining to psychosocial risk factors for headache and migraine progression, current behavioral and psychological treatments, and consider promising treatments.

BACKGROUND

Headache and migraine are common and associated with significant burden and disability. Current treatments targeting psychosocial risk factors show modest outcomes and do not directly address the impact of early life adversity, including the development of maladaptive emotional processing. An intervention that could address these factors and include components of current evidence-based interventions may lead to improved outcomes.

METHODS

We searched PubMed and Google Scholar for articles through December 2022. Search terms included headache, migraine, psychological interventions, behavioral interventions, cognitive-behavioral therapy, mindfulness, psychiatric comorbidities, adverse childhood experiences, trauma, and emotional processing.

RESULTS

Trauma and childhood adversity show a correlation with headache and migraine progression. Developmental adversity and trauma interfere with adaptive emotional processing, which may worsen headache and migraine symptoms, while adaptive ways of experiencing emotions are shown to improve symptoms. Current behavioral and psychological interventions, such as cognitive-behavioral and mindfulness therapies, are effective treatments for headache, but they produce small to medium effect sizes and do not directly address the impact of trauma and emotional conflicts-common factors that contribute to chronicity and disability, especially among certain subpopulations of headache patients such as those with migraine. Thus, there exists a gap in current treatment.

CONCLUSION

There is a gap in headache and migraine treatment for those patients who have a history of trauma, childhood adversity, and maladaptive emotional processing. We suggest that an integrated psychological treatment that includes components of current evidence-based interventions and addresses gaps by focusing on processing trauma-related emotions may improve chronic and debilitating symptoms.

"I don't have chronic back pain anymore": Patient Experiences in Pain Reprocessing Therapy for Chronic Back Pain

In a recently published randomized controlled trial, two-thirds of the patients receiving a novel psychological treatment, pain reprocessing therapy (PRT), reported elimination or near-elimination of chronic back pain. The mechanisms of PRT and related treatments remain poorly understood but are hypothesized to center on pain reappraisal, fear reduction, and exposure-potentiated extinction. Here, we investigated treatment mechanisms from the participants' perspective. A sample of 32 adults with chronic back pain who received PRT completed semi-structured posttreatment interviews about their treatment experiences. The interviews were analyzed with multiphase thematic analysis. The analyses identified 3 major themes reflecting participants' understanding of how PRT led to pain relief: 1) reappraisal to reduce fear of pain, which included guiding participants to relate to pain as a helpful indicator, overcoming pain-related fear and avoidance, and reconceptualizing pain as a "sensation;" 2) the link between pain, emotions, and, stress, which included gaining insight into these connections and resolving difficult emotions; and 3) social connections, which included patient-provider alliance, therapist belief in the treatment model, and peer models of recovery from chronic pain. Our findings support the hypothesized mechanisms of PRT centered on pain reappraisal and fear reduction, but also highlight additional processes from the participants' perspective, including a focus on emotions and relationships. This study underscores the value of qualitative research methods in illuminating the mechanisms of novel pain therapies. PERSPECTIVE: This article presents participants' perspectives on their experience engaging in a novel psychotherapy for chronic pain, PRT. Through pain reappraisal, linking pain, emotions, and stress, and connecting with their therapist and peers, many participants reported an elimination or near-elimination of their chronic back pain with therapy.

Managing medical and psychiatric multimorbidity in older patients

Aging increases susceptibility both to psychiatric and medical disorders through a variety of processes ranging from biochemical to pharmacologic to societal. Interactions between aging-related brain changes, emotional and psychological symptoms, and social factors contribute to multimorbidity - the presence of two or more chronic conditions in an individual - which requires a more patient-centered, holistic approach than used in traditional single-disease treatment guidelines. Optimal treatment of older adults with psychiatric and medical multimorbidity necessitates an appreciation and understanding of the links between biological, psychological, and social factors - including trauma and racism - that underlie physical and psychiatric multimorbidity in older adults, all of which are the topic of this review.

[Emotions in chronic pain : Changes in the course of day clinic interdisciplinary multimodal pain therapy]

RESEARCH QUESTION

The present study examined the extent to which emotional experience and emotional competence (EC) change in people with chronic pain during interdisciplinary multimodal pain treatment (IMPT).

METHODS

The study included N = 184 adult German-speaking individuals with non-cancer-related chronic pain. They completed a day clinic IMPT. The frequency of specific emotions (anger, etc.) and EC was assessed at three measurement time points using the Questionnaire for Emotion-Specific Self-Assessment of Emotional Competencies (ERSQ-ES) and the Emotional Competency Questionnaire (ECQ). The course results were analyzed descriptively, inferentially, and using linear regression.

RESULTS

Positive emotions were experienced more frequently (effect size r = 0.40; p < 0.001) and negative emotions less frequently (r = 0.39, p < 0.001) at end of therapy. The experience of anger decreased particularly strongly (r = 0.52; p < 0.001). Self-assessed EC did not change during the IMPT (χ2ECQ_total (2) = 0.09; p = 0.956). EC largely explained the variance in the frequency experience of positive (R2 = 0.468) and negative emotions (R2 = 0.390).

DISCUSSION

Improvements in patient-reported frequencies of positive and negative emotions during IMPT were demonstrated. Further research should validate these results using a control group. Even though no explicit increase in competence was perceivable for the studied subjects, EC had a high predictive value for emotion frequency. Future therapy designs and evaluations should focus more on changes of emotional experience.

The Effects of Virtual Reality Neuroscience-based Therapy on Clinical and Neuroimaging Outcomes in Patients with Chronic Back Pain: A Randomized Clinical Trial

Chronic pain remains poorly managed. The integration of innovative immersive technologies (i.e., virtual reality (VR)) with recent neuroscience-based principles that position the brain as the key organ of chronic pain may provide a more effective pain treatment than traditional behavioral therapies. By targeting cognitive and affective processes that maintain pain and potentially directly changing neurobiological circuits associated with pain chronification and amplification, VR-based pain treatment has the potential for significant and long-lasting pain relief. We tested the effectiveness of a novel VR neuroscience-based therapy (VRNT) to improve pain-related outcomes in n = 31 participants with chronic back pain, evaluated against usual care (n = 30) in a 2-arm randomized clinical trial ( NCT04468074) . We also conducted pre- and post-treatment MRI to test whether VRNT affects brain networks previously linked to chronic pain and treatment effects. Compared to the control condition, VRNT led to significantly reduced pain intensity (g = 0.63) and pain interference (g = 0.84) at post-treatment vs. pre-treatment, with effects persisting at 2-week follow-up. The improvements were partially mediated by reduced kinesiophobia and pain catastrophizing. Several secondary clinical outcomes were also improved, including disability, quality of life, sleep, and fatigue. In addition, VRNT was associated with modest increases in functional connectivity of the somatomotor and default mode networks and decreased white matter fractional anisotropy in the corpus callosum adjacent to anterior cingula, relative to the control condition. This, VRNT showed preliminary efficacy in significantly reducing pain and improving overall functioning, possibly via changes in somatosensory and prefrontal brain networks.

Determining Profiles of Pain-Specific and General Emotion Regulation Skills and Their Relation to 12-Month Outcomes Among People With Chronic Pain

Difficulties with pain-specific emotion regulation (ER; eg, pain catastrophizing, pain acceptance) are associated with poor pain outcomes. Less is known about how general ER relates to pain outcomes, or the extent to which pain-specific and general ER interact. In a sample (N = 1,453) of adults with chronic pain, the current study used latent profile analysis to identify subgroups of people with distinct pain-specific and general ER profiles, and determined how subgroup membership at baseline related to pain severity, pain interference, depression and anxiety symptoms at 12-month follow-up. Four groups were identified: 1) general ER difficulties only (29.6%); 2) pain-specific and general ER difficulties (26.3%); 3) skillful pain-specific and general ER (24.6%); 4) pain-specific ER difficulties only (19.4%). Controlling for auto-correlation and demographic covariates, those with pain-specific and general ER difficulties had the worst outcomes in all domains. Membership to other groups did not differentiate between pain severity or interference outcomes; those skillful in pain-specific and general ER had the lowest depression and anxiety symptoms at 12 months. General ER difficulties are common among adults with chronic pain and raise relative risk when paired with pain-specific ER difficulties. Findings offer potential directions for individualizing pain psychology treatment. PERSPECTIVE: This article shows that people with chronic pain have different sets of strengths and difficulties when it comes to regulating emotions related and/or unrelated to the experience of pain itself. Understanding an individual's unique constellation of emotion regulation skills and difficulties might help personalize the psychological treatment of pain.

Reconsidering Fordyce's classic article, "Pain and suffering: what is the unit?" to help make our model of chronic pain truly biopsychosocial

ABSTRACT

The biopsychosocial model (BPS) of chronic pain aspires to be comprehensive, incorporating psychological and social factors omitted from biomedical models. Although psychosocial factors are viewed as highly influential in understanding behavioral and psychological responses to pain, these factors are usually viewed as modifiers of biological causes of the experience of pain itself, rather than as equal contributors to pain. To further advance the BPS model, we re-examine a classic 1994 article by Wilbert "Bill" Fordyce, "Pain and suffering: what is the unit?" In this article, Fordyce suggested that pain-related disability and suffering should be viewed as "transdermal," as having causes both inside and outside the body. We consider Fordyce's article theoretically important because this concept allows us to more fully break free of the medical model of chronic pain than customary formulations of the BPS model. It makes it possible to place psychological and social factors on an equal footing with biological ones in explaining pain itself and to remove distinctions between pain mechanisms and pain meanings. The brain's salience network now offers a platform on which diverse influences on pain experience-from nociception to multisensory indicators of safety or danger-can be integrated, bridging the gap between impersonal nociceptive mechanisms and personal meanings. We also argue that Fordyce's article is practically important because this concept expands the BPS model beyond the bounds of the clinical encounter, opening the door to the full range of social, psychological, and biological interventions, empowering patients and nonmedical providers to tackle chronic pain.

Chronic Pain in Older Adults: A Neuroscience-Based Psychological Assessment and Treatment Approach

Chronic pain remains a serious healthcare challenge, particularly for older adults who suffer substantial disability and are susceptible to serious risks from pain medications and invasive procedures. Psychotherapy is a promising option for older adults with chronic pain, since it does not contribute to medical or surgical risks. However, standard psychotherapies for chronic pain, including cognitive-behavioral therapy (CBT), acceptance and commitment therapy, and mindfulness-based interventions, produce only modest and time-limited benefits for older adults. In this article, we describe a novel, evidence-based psychological assessment and treatment approach for older adults with chronic pain, including a detailed case example. The approach begins with reviewing patients' pain, psychosocial, and medical histories to elicit evidence of a subtype of chronic pain called centralized (primary, nociplastic, or psychophysiologic) pain, which is highly influenced and may even be caused by life stress, emotions, and alterations in brain function. Patients then undertake a novel psychotherapy approach called emotional awareness and expression therapy (EAET) that aims to reduce or eliminate centralized pain by resolving trauma and emotional conflicts and learning healthy communication of adaptive emotions. Our published preliminary clinical trial (n = 53) indicated that EAET produced statistically significant and large effect size advantages over CBT in pain reduction and marginally greater improvements in pain interference than CBT for older adults with chronic musculoskeletal pain. Geriatric mental healthcare providers may learn this assessment and treatment approach to benefit many of their patients with chronic pain.

Internet-based emotional awareness and expression therapy for somatic symptom disorder: A randomized controlled trial

OBJECTIVE

Somatic symptom disorder (SSD) is commonly encountered in health care settings. Cognitive-behavioural treatments have been most extensively studied, but they tend to have small effects of temporary duration. Emotional awareness and expression therapy (EAET) is a newly developed treatment for SSD, targeting emotional processing of trauma and conflict as a mechanism of symptom change. In an earlier uncontrolled study of self-guided, internet-administrated EAET (I-EAET), we found substantial reductions in somatic symptoms, prompting the need for a randomized controlled trial of I-EAET.

METHODS

We conducted a 2-arm RCT, comparing 10-week I-EAET (n = 37) to a waitlist control (WL; n = 37). Primary outcomes were reductions of somatic symptoms (PHQ-15) and pain intensity (BPI-4) at post-treatment, with a 4-month evaluation of effect duration. We also analysed emotional processing (EPS-25) and depression (PHQ-9) as possible mediators of I-EAET's effects.

RESULTS

Compared to controls, I-EAET significantly reduced somatic symptoms at both post-treatment and follow-up. I-EAET also reduced pain, depression, insomnia, and anxiety at post-treatment, but these effects were not retained at follow-up. As hypothesized, a facet of emotional processing partially mediated the treatment effect on somatic symptoms, even when controlling for depression.

CONCLUSIONS

Although treatment effects were smaller than in the previous uncontrolled trial, I-EAET is a promising treatment for SSD, with a minority of patients (around 20%) experiencing substantial clinical improvement. The benefits of I-EAET are partially mediated by improved emotional processing. Future research should identify and target patients who respond best to I-EAET and develop tailored treatment to enhance treatment effects. (Preregistered at clinicaltrials.gov: NCT04751825.).

"Pain, Stress, and Emotions": Uncontrolled trial of a single-session, telehealth, emotional awareness and expression therapy class for patients with chronic pain

Objectives

Trauma- and emotion-focused chronic pain interventions, particularly Emotional Awareness and Expression Therapy (EAET), show much promise for reducing pain and improving functioning. We developed a novel, single-session, telehealth-delivered EAET class ("Pain, Stress, and Emotions"; PSE) and tested it on adults with chronic pain of mixed etiology.

Methods

After an initial developmental phase, we conducted an uncontrolled trial, providing PSE to 74 individuals with chronic pain (63.5% female; 64.9% White; 60.8% with pain duration >5 years) in four class administrations. Participants completed self-report measures (primary outcomes: pain intensity and pain interference) at baseline and multiple follow-ups to 12 weeks. Linear mixed-models examined changes over time, and effect sizes were calculated on change from baseline to 4-week (primary endpoint) and 12-week follow-ups. The trial was registered with clinicaltrials.gov (NCT05014126).

Results

Participants reported high satisfaction with the PSE class. Pain intensity showed a significant, medium reduction across time (p < .001; d = 0.60 at 4 weeks); one-quarter of participants had clinically meaningful pain reduction (≥30%). Pain interference had a large reduction (p < .001; d = 0.74). There were significant but smaller improvements in most secondary outcomes (ds = 0.15 to 0.55; ps < .01). Effects were generally maintained or increased at 12-week follow-up. Higher education and baseline ambivalence over emotional expression predicted greater pain reductions.

Conclusions

People taking this EAET class had reduced pain severity and interference and improvements in other pain-related outcomes. The single-session, telehealth class holds promise as an easily delivered, efficient, and potentially impactful intervention for some patients with chronic pain, although controlled trials are needed.

Defining pain-validation: The importance of validation in reducing the stresses of chronic pain

Purpose

To validate an individual's feelings or behaviour is to sanction their thoughts or actions as worthy of social acceptance and support. In contrast, rejection of the individual's communicated experience indicates a denial of social acceptance, representing a potential survival threat. Pain-invalidation, though ill-defined, appears to be a fundamental component of psychosocial stress for people with chronic pain. As such, the aim of this paper was to define pain-validation and outline its importance for those with chronic pain.

Methods

The pain-validation construct was defined using themes inherent in the narratives of those with chronic pain, as identified in a previously published systematic search and thematic analysis, together with examination of additional literature on pain-validation in the clinical context.

Results

We present a construct definition, proposing that pain-validation must necessarily include: (i) belief that the pain experience is true for the individual, (ii) acceptability of the individual's expressions of pain, and (iii) communication of belief and acceptability to the individual experiencing pain. Further, we outline the importance of pain-validation as a protective factor and means of reducing many of the psychosocial stresses of chronic pain; for example, by indicating social support for pain-coping, buffering negative emotions, and re-enforcing unity and shared identity.

Implications

The role of pain-validation in the current era of pain management intervention is discussed. Adhering to interventions that involve cognitive and behavioural change is often difficult. Acknowledging and validating the acceptability of the patient's pain experience in the early stages of pain management may, therefore, be a key component of intervention that encourages compliance to the treatment plan and achieving therapeutic goals.

The Pain-Invalidation Scale: Measuring Patient Perceptions of Invalidation Toward Chronic Pain

Increasing evidence reveals the damaging impact of having one's chronic pain symptoms invalidated through disbelief, discrediting, and critical judgement. In other instances, a caregiver's over-attentiveness to the daily tasks of individuals with pain can be problematic, potentially undermining rehabilitation. The aim of this study was to develop an instrument to measure different aspects of invalidation perceived by people with chronic pain. Item generation was informed through literature review and a thematic analysis of narratives from 431 peer-reviewed articles. The crowdsourcing platform Prolific was used to distribute survey items to participants. In Study 1A, Principal Component Analysis was performed on data from 302 respondents, giving rise to 4 subscales, including: Invalidation by the Self, Invalidation by Immediate Others, Invalidation by Healthcare Professionals, and Invalidation by Over-attentive Others. Confirmatory Factor Analysis of data collected from aonther 308 individuals in Study 1B supported the 4-factor model of the Pain-Invalidation Scale (Pain-IS) and identified a best-fit model with 24 items. The Pain-IS was further validated in another 300 individuals in Study 2. The Pain-IS demonstrates sound psychometric properties and may serve as a valuable tool for use by clinicians in the detection of pain-invalidation issues, as a first step in patient pain management. Perspective. Links between pain-invalidation and pain levels, as well as functional detriment, highlight the importance of having one's chronic pain experience heard, believed and accepted. The Pain-Invalidation Scale is designed to identify domains where invalidation of the patient's pain should be addressed to promote emotional processing, treatment adherence and improved outcomes.

The Longitudinal Relationship Between Emotion Regulation and Pain-Related Outcomes: Results From a Large, Online Prospective Study

People with chronic pain engage in various strategies, such as pain catastrophizing and pain acceptance, to regulate the difficult emotional aspects of living with pain. Engagement in these strategies is known to influence pain severity and pain interference. However, less research has examined the extent to which general emotion regulation, the ability to identify emotions and engage in strategies to alter emotions, relates to pain-related outcomes. The current study, a large (N = 1453) online prospective study of adults with chronic pain, employed theory-driven assessment of emotion regulation to determine the extent to which general difficulties with emotion regulation at baseline relate to pain severity and pain interference at three-month follow-up, above and beyond pain catastrophizing and pain acceptance. We conducted a series of path models, controlling for demographic covariates and baseline pain severity and pain interference. Pain catastrophizing and pain acceptance at baseline significantly predicted pain interference at three-month follow-up. However, when indices of general emotion regulation were entered into the model, the associations between pain catastrophizing and pain interference (B = .009, P = .153) were no longer statistically significant. Alexithymia emerged as a significant predictor of pain severity (B = .012, P = .032) and pain interference (B = .026, P < .001). These findings highlight the value of considering the role of general emotion regulation (particularly identifying and describing emotions), in addition to pain-specific experiences, in understanding risk for poor pain-related outcomes. PERSPECTIVE: In addition to pain catastrophizing and pain acceptance, difficulties regulating emotions in general (particularly elevated alexithymia) relates to pain outcomes three months later. These findings shed light on risk for poor pain outcomes and point to general emotion regulation as a potentially important target of chronic pain intervention.

Eliciting emotional expressions in psychodynamic psychotherapies using telehealth: a clinical review and single case study using emotional awareness and expression therapy

The COVID-19 pandemic and ensuing social distancing requirements resulted in an abrupt transition in the provision of most mental healthcare to telehealth; yet it was, at first, unclear whether patients' emotional expressions - of great import to the success of many psychodynamic therapies - could be facilitated using teletherapy. This article first presents a targeted literature review focused on emotional expressions in psychotherapy and implementing psychodynamic therapy over telehealth and then describes our clinical experience transitioning a psychodynamically-informed, evidence-based, and experiential group treatment for chronic pain, emotional awareness and expression therapy (EAET), to video telehealth at VA Greater Los Angeles Healthcare System. We discuss barriers we encountered in our implementation of EAET over video telehealth but also illustrate the ultimate success of the approach using verbatim excerpts from our therapeutic work, which aim to demonstrate the potential to facilitate powerful emotional expressions over video telehealth when conducting a psychodynamically-informed treatment. We examine the possible applications for video telehealth to maintain emotionally focused, psychodynamic psychotherapy administration and enhance its teaching and training. Although we describe limitations of our specific approach, ultimately, our experience supports the potential efficacy of experiential, emotion-focused psychodynamic therapies in a telehealth setting.

Neuroimaging Mechanism of Cognitive Behavioral Therapy in Pain Management

Purpose. To review the recent neuroimaging studies on cognitive-behavioral therapy (CBT) for pain management, with the aim of exploring possible mechanisms of CBT. Recent Findings. Current studies can be divided into four categories, mixed pain, fibromyalgia, migraine, and experimental pain, based on the type of disease included, with the same or different changes of brain regions after CBT intervention. According to structural and functional MRI analyses, changes of brain gray matter volume, activation and deactivation of brain regions, and intrinsic connectivity between brain regions were observed after CBT sessions. The brain regions involved mainly included some areas related to cognitive and emotional regulation. After comparison, the DLPFC, OFC, VLPFC, PCC and amygdala were found to be recurrent in multiple studies and may be key regions for CBT intervention in pain management. In the treatment of mixed chronic pain, CBT may decrease the gray matter volume of DLPFC, reduce ICN connection of OFC within the DAN network, and increase fALFF of the PCC. For FM intervention, CBT may activate the bilateral OFC and VLPFC, while in migraine, only the right OFC, VLPFC, and DLPFC were found to be more activated after CBT. In addition, the differential action of the left and right amygdala has also been shown in the latest study of migraine. In heat-evoked pain, CBT may increase the deactivation of the PCC, the connectivity between the DMN and right VLPFC, while diminishing the deactivation of VLPFC. Summary. After CBT, the brain showed stronger top-down pain control, cognitive reassessment, and altered perception of stimulus signals (chronic pain and repeated acute pain). The DLPFC, OFC, VLPFC, PCC, and amygdala may be the key brain regions in CBT intervention of pain.

At the Intersection of Anger, Chronic Pain, and the Brain: A Mini-Review

Chronic pain remains one of the most persistent healthcare challenges in the world. To advance pain treatment, experts have recently introduced research-driven subtypes of chronic pain based on proposed underlying mechanisms. Nociplastic pain (e.g., nonspecific chronic low back or fibromyalgia) is one such subtype which may involve a greater etiologic role for brain plasticity, painful emotions induced by life stress and trauma, and unhealthy emotion regulation. In particular, correlational and behavioral data link anger and the ways anger is regulated with the presence and severity of nociplastic pain. Functional neuroimaging studies also suggest nociplastic pain and healthy anger regulation demonstrate inverse patterns of activity in the medial prefrontal cortex and amygdala; thus, improving anger regulation could normalize activity in these regions. In this Mini-Review, we summarize these findings and propose a unified, biobehavioral model called the Anger, Brain, and Nociplastic Pain (AB-NP) Model, which can be tested in future research and may advance pain care by informing new treatments that address anger, anger regulation, and brain plasticity for nociplastic pain.

Emotional Processing and Its Association to Somatic Symptom Change in Emotional Awareness and Expression Therapy for Somatic Symptom Disorder: A Preliminary Mediation Investigation

Objective: The aim of this study was to investigate emotional processing as a potential mediator in therapist-guided, internet-based Emotional Awareness and Expression Therapy (I-EAET) for somatic symptom disorder, using data from a previously published pilot study.

Methods: Participants (N = 52) engaged in a 9-week I-EAET treatment. Before treatment and each week during treatment (i.e., 10 weekly measurements), emotional processing was assessed with the Emotional Processing Scale-25 (EPS-25), which contains five subscales, and somatic symptoms were assessed with the Patient Health Questionnaire-15 (PHQ-15).

Results: Mediation analyses using linear mixed models showed that two EPS-25 subscales—Signs of Unprocessed Emotions and Impoverished Emotional Experience—were uniquely associated with somatic symptom reduction. The proportion of the mediated effect was 0.49, indicating that about half of the total association of the PHQ-15 with symptoms was accounted for by the two EPS-25 subscales.

Conclusion: This preliminary mediation analysis suggests that improved emotional processing is associated with change in somatic symptoms in I-EAET. However, randomized controlled and comparison trials are needed to establish that I-EAET creates the change in emotional processing and that such changes are specific to I-EAET.

Psychophysiologic symptom relief therapy for chronic back pain: a pilot randomized controlled trial

Introduction

Chronic back pain is the leading cause of disability in the United States. Based on the hypothesis that nonspecific back pain may be rooted in a psychophysiologic etiology, we propose a new approach to chronic back pain.

Objectives

A pilot study was conducted to assess whether psychophysiologic symptom relief therapy (PSRT) can reduce disability and back pain bothersomeness for patients with chronic back pain.

Methods

This was a three-armed, randomized trial for adults with nonspecific chronic back pain that compared PSRT with usual care and an active comparator (mindfulness-based stress reduction [MBSR]). Psychophysiologic symptom relief therapy-randomized participants received a 12-week (36 hours) course based on the psychophysiological model of pain. All groups were administered validated questionnaires at baseline and at 4, 8, 13, and 26 weeks. The primary outcome was the reduction in pain disability measured by the Roland-Morris Disability Questionnaire.

Results

The mean Roland-Morris Disability Questionnaire score for the PSRT group (n = 11) decreased from 9.5 (±4.3 SDs) to 3.3 (±5.1) after 26 weeks which was statistically significant compared with both MBSR (n = 12) (P = 0.04) and usual care (n = 12) (P = 0.03). Pain bothersomeness scores and pain-related anxiety decreased significantly over 26 weeks in PSRT compared with MBSR and usual care (data in manuscript). At 26 weeks, 63.6% of the PSRT arm reported being pain free (0/10 pain) compared with 25.0% and 16.7% in MBSR and usual care arms, respectively. Psychophysiologic symptom relief therapy attendance was 76%, and there was 100% follow-up of all groups.

Conclusion

Psychophysiologic symptom relief therapy is a feasible and potentially highly beneficial treatment for patients with nonspecific back pain.

Characterization of chronic overlapping pain conditions in patients with chronic migraine: A CHOIR study

OBJECTIVE

Chronic overlapping pain conditions (COPCs) represent a co-aggregation of widespread pain disorders. We characterized differences in physical and psychosocial functioning in patients with chronic migraine (CM) and those with CM and COPCs.

BACKGROUND

Patients with CM and COPCs have been identified as a distinct subgroup of patients with CM, and these patients may be vulnerable to greater symptom severity and burden.

METHODS

Data were extracted from Collaborative Health Outcomes Information Registry (an open-source learning health-care system), completed at the patients' first visit at a large tertiary care pain management center and electronic medical records. In 1601 patients with CM, the number of non-cephalic areas of pain endorsed on a body map was used to examine the differences in pain, physical and psychosocial function, adverse life experience, and health-care utilization.

RESULTS

Patients endorsing more body map regions reported significantly worse symptoms and function across all domains. Scored on a t-score metric (mean = 50, SD = 10), endorsement of one additional body map region corresponded with a 0.69-point increase in pain interference (95% CI = 0.55, 0.82; p < 0.001; Cohen's f = 0.328), 1.15-point increase in fatigue (95% CI = 0.97, 1.32; p < 0.001; Cohen's f = 0.432), and 1.21-point decrease in physical function (95% CI = -1.39, -1.03; p < 0.001; Cohen's f = 0.560). Patients with more widespread pain reported approximately 5% more physician visits (95% CI = 0.03, 0.07; p < 0.001), and patients reporting adverse life events prior to age 17 endorsed 22% more body map regions (95% CI = 0.11, 0.32; p < 0.001).

CONCLUSIONS

Patients with CM and other overlapping pain conditions as noted on the body map report significantly worse pain-related physical function, psychosocial functioning, increased health-care utilization, and greater association with adverse life experiences, compared with those with localized CM. This study provides further evidence that patients with CM and co-occurring pain conditions are a distinct subgroup of CM and can be easily identified through patient-reported outcome measures.

Short-term psychodynamic psychotherapy for functional somatic disorders: A systematic review and meta-analysis of within-treatment effects

OBJECTIVE

A recent meta-analysis of 17 randomized, controlled trials (RCTs) showed that Short-term Psychodynamic Psychotherapy (STPP) for functional somatic disorders (FSD) reduced somatic symptoms compared to wait list, minimal treatment, and treatment-as-usual controls. A clinically important yet unanswered question is how much improvement patients experience within STPP treatment.

METHODS

Following a systematic search, we identified STPP trials presenting data at baseline and post-treatment/follow-up. Meta-analyses determined the magnitude of changes in somatic symptoms and other outcomes from before to after STPP, and analyses examined effect sizes as a function of study, therapy, and patient variables.

RESULTS

We identified 37 trials (22 pre-post studies and 15 RCTs) totaling 2094 patients treated an average of 13.34 sessions for a range of FSD. Across all studies, somatic symptoms improved significantly from pre-treatment to short-term follow-up with a large effect size (SMD = -1.07), which was maintained at long-term follow-up (SMD = -0.90). After excluding two outlier studies, effects at short- and medium-term follow-up remained significant but were somewhat reduced in magnitude (e.g., short-term SMD = -0.73). Secondary outcomes including anxiety, depression, disability, and interpersonal problems had medium to large effects. Effects were larger for studies of STPP that were longer than 12 sessions or used an emotion-focused type of STPP, and for chronic pain or gastrointestinal conditions than for functional neurological disorders.

CONCLUSIONS

STPP results in moderate to large improvements in multiple outcome domains that are sustained in long-term follow-up. STPP is an effective treatment option for FSD and should be included in treatment guidelines.

Emotional awareness and other emotional processes: implications for the assessment and treatment of chronic pain

Emotional awareness (EA) is a key emotional process that is related to the presence and severity of chronic pain (CP). In this report, we describe primary and secondary emotions, discuss the distinction between emotional states and emotional regulation/processing, and summarize theory and research highlighting the significance of EA for CP. We describe ways to assess EA and diagnose centrally-mediated CP, for which emotional processes appear most relevant. We review several psychological interventions designed to enhance EA as well as several broader emotional processing treatments developed to address trauma and psychosocial conflicts underlying many patients' pain. We conclude by offering our perspective on how future integration of emotional processing into pain care could promote recovery from CP.

Internet-Administered Emotional Awareness and Expression Therapy for Somatic Symptom Disorder With Centralized Symptoms: A Preliminary Efficacy Trial

Background: There is growing evidence that trauma, psychosocial conflict, and difficulties with emotional processing contribute to centralized somatic symptoms. Emotional Awareness and Expression Therapy (EAET) was developed to address these factors and reduce symptoms, and EAET has shown efficacy in face-to-face formats. No trial of an internet-delivered EAET (I-EAET) exists, however, so we developed such an intervention and conducted an uncontrolled feasibility and potential efficacy trial of I-EAET for patients with Somatic Symptom Disorder (SSD) with centralized symptoms (SSD-CS). Method: After screening potential participants, a sample of 52 patients (50 women, two men; age M = 49.6, SD = 11.9) diagnosed with SSD-CS initiated treatment. I-EAET consisted of nine weekly modules focused on psychoeducation, emotional awareness and exposure, and anxiety regulation with self-compassion. Therapists communicated with each patient by email for about 20 min per week during treatment, answering questions and giving feedback on homework assignments. Patients completed measures of somatic symptoms, depression, anxiety, trauma-related symptoms, and functional disability before treatment and again at post-treatment and 4-month follow-up. Results: A large reduction in somatic symptoms (PHQ-15) occurred pre-to post-treatment (d = 1.13; 95% CI: 0.84-1.47) which was fully maintained at 4-month follow-up (d = 1.19; 95% CI: 0.88-1.56). Twenty-three percent of the patients at post-treatment and 27% at follow-up achieved a 50% or greater reduction in somatic symptoms, and about 70% achieved a minimally important clinical difference. In addition, at post-treatment, there were small to medium reductions (d's from 0.33 to 0.72) in anxiety (GAD-7), depression (PHQ-9), trauma-related symptoms (PCL-5), and functional disability (Sheehan Disability Scale). For all of these secondary outcomes, improvements were slightly to substantially larger at follow-up than at post-treatment (d's from 0.46 to 0.80). Conclusion: I-EAET appears to be a feasible treatment for adults with SSD and centralized symptoms, resulting in substantial and durable improvement not only in somatic symptoms but in other psychiatric symptoms and functioning. Controlled trials are needed determine the effects of I-EAET specifically and how this approach compares to face-to-face EAET and to other internet-delivered treatments, such as cognitive-behavioral interventions. Research should also identify treatment responders and mechanisms of change in EAET. Clinical Trial Registration: www.ClinicalTrials.gov, identifier: NCT04122846.