Confirming the mechanisms behind cognitive-behavioural therapy effectiveness in chronic pain using structural equation modeling in a sample of patients with temporomandibular disorders

Psychological treatments for temporomandibular disorder pain-A systematic review

OBJECTIVE

Temporomandibular disorders (TMD) are common. They affect abilities for carrying out daily tasks and influence different psychological aspects. In addition to standard treatment, psychological treatments have been suggested. The aim was to investigate the effects of psychological treatments on patients with painful TMD in a short- and long-term perspective.

MATERIALS AND METHODS

An electronic search was conducted in the databases MEDLINE, CINAHL, EMBASE, the Cochrane Central Registry of Controlled Trials (CENTRAL), and Web of Science for randomized clinical trials (RCTs) reporting psychological interventions for TMD. Registered beforehand in PROSPERO (CRD42022320106). In total, 18 RCTs were included; six RCTs that could be used in the meta-analysis, and all 18 RCTs were used in the narrative synthesis. Risk of bias was assessed by the Cochrane's tool for assessing risk of bias and certainty of evidence by GRADE.

RESULTS

The narrative synthesis indicates that psychological treatment options seem equivalent to standard treatment for painful TMD. The meta-analysis showed that a combination of psychological treatment and standard treatment and manual treatment (very low-quality evidence) are significantly better in pain reduction than just counselling and standard treatments of TMD.

CONCLUSION

This study indicates that psychological treatments seem to reduce pain intensity in individuals with painful TMD, and that the effect seems to be equally good as standard treatment. However, a combination of psychological treatments and standard treatments seems to have an even better effect. This indicates that psychological treatments are promising as an additional treatment approach for painful TMDs.

Individual Dimensions of Pain Catastrophizing Do Not Mediate the Effect of Sociodemographic and Psychological Factors on Chronic Orofacial Pain Severity, Interference, and Jaw Limitation: A Structural Equation Modeling Approach

Pain catastrophization (PC), involving rumination, magnification, and helplessness, can be viewed as a coping strategy associated with chronic pain. PC is considered a driving force in mediating pain-related outcomes, but it is still unclear whether PC mediates the relationship between psychological and sociodemographic factors with chronic pain when considered in a single model. Using baseline data from a parent study, this study examined the effect of positive and negative psychological and sociodemographic factors on pain severity, interference, and jaw limitation mediated by the PC dimensions in a sample of 397 temporomandibular disorder (TMD) participants using structural equation modeling (SEM). SEM revealed that pain severity regressed on age, sex, education, and income; interference regressed on positive and negative psychological factors, education, and income; and jaw limitation regressed on age. The PC dimensions did not individually mediate these relationships. Although they jointly mediated the relationships between negative psychological factors and pain severity and between age and pain interference, the effect size was small, suggesting that PC is not a critical factor in mediating TMD pain outcomes. Reducing negative cognitions, not just PC, may be of greatest benefit to the most vulnerable TMD populations. PERSPECTIVE: This study examines sociodemographic and psychological factors that affect orofacial pain, finding that the pain catastrophizing dimensions do not mediate these relationships. Understanding which factors most strongly affect pain outcomes will help identify targets for intervention to produce the greatest benefit for the most vulnerable persons suffering from pain.

Nonsurgical Management of Temporomandibular Joint Arthropathy

Arthropathy is a broad diagnostic term for any pathologic condition afflicting one or more joints of the body. Temporomandibular joint (TMJ) arthropathy is an umbrella term that may be applied to mechanical dysfunction or disease of one or both TMJs. This article provides evidence-based recommendations for conducting a patient evaluation, initiating a diagnostic workup, formulating an assessment, and instituting various nonsurgical modalities for the treatment of TMJ arthropathies.

The effect of trait self-control on dyspnoea and tolerance to a CO2 rebreathing challenge in healthy males and females

BACKGROUND

High trait self-control is associated with greater tolerance of unpleasant sensations including effort and pain. Dyspnoea and pain have several commonalities and this study aimed to investigate for the first time whether trait self-control influences responses to a hypercapnic rebreathing challenge designed to induce dyspnoea. As sex also influences tolerance to dyspnoea, we also sought to investigate whether this moderated the role of trait self-control.

METHODS

Participants (n = 65, 32 females) scoring high or low for trait self-control, performed a standardised rebreathing challenge, in which inspired carbon dioxide (CO₂) gradually increased over a period of 6 min or until an intolerable level of dyspnoea. Air hunger (AH) intensity - a distinctive quality of dyspnoea, was measured every 30 s. The multidimensional dyspnoea profile (MDP) was completed after the rebreathing challenge for a more complete overview of breathing discomfort.

RESULTS

Males high in trait self-control (SCHIGH) (302 ± 42 s), tolerated the rebreathing challenge for longer than males low in self-control (SCLOW) (252 ± 66 s, P = 0.021), experienced slower increases in AH intensity during the rebreathing challenge (0.03 ± 0.01 cm^.s ^- 1 vs. 0.04 ± 0.01 cm^.s ^- 1,P = 0.045) and reported lower perceived mental effort on the MDP (4.94 ± 2.46 vs. 7.06 ± 1.60, P = 0.007). There was no difference between SCHIGH and SCLOW females for challenge duration. However, SCHIGH females (9.29 ± 0.66 cm) reported greater air hunger at the end of the challenge than SCLOW females (7.75 ± 1.75 cm, P = 0.003). It is possible that SCLOW females were unwilling to tolerate the same perceptual intensity of AH as the SCHIGH females.

CONCLUSIONS

These results indicate that individuals high in trait self-control are more tolerant of dyspnoea during a CO₂ rebreathing challenge than low self-control individuals. Tolerance of the stimulus was moderated by the sex of the participant, presenting an interesting opportunity for future research.

Psychological therapies for temporomandibular disorders (TMDs)

BACKGROUND

Temporomandibular disorders (TMDs) are a group of musculoskeletal disorders affecting the jaw. They are frequently associated with pain that can be difficult to manage and may become persistent (chronic). Psychological therapies aim to support people with TMDs to manage their pain, leading to reduced pain, disability and distress.

OBJECTIVES

To assess the effects of psychological therapies in people (aged 12 years and over) with painful TMD lasting 3 months or longer.

SEARCH METHODS

Cochrane Oral Health's Information Specialist searched six bibliographic databases up to 21 October 2021 and used additional search methods to identify published, unpublished and ongoing studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of any psychological therapy (e.g. cognitive behaviour therapy (CBT), behaviour therapy (BT), acceptance and commitment therapy (ACT), mindfulness) for the management of painful TMD. We compared these against control or alternative treatment (e.g. oral appliance, medication, physiotherapy).

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. We reported outcome data immediately after treatment and at the longest available follow-up. We used the Cochrane RoB 1 tool to assess the risk of bias in included studies. Two review authors independently assessed each included study for any risk of bias in sequence generation, allocation concealment, blinding of outcome assessors, incomplete outcome data, selective reporting of outcomes, and other issues. We judged the certainty of the evidence for each key comparison and outcome as high, moderate, low or very low according to GRADE criteria.

MAIN RESULTS

We identified 22 RCTs (2001 participants), carried out between 1967 and 2021. We were able to include 12 of these studies in meta-analyses. The risk of bias was high across studies, and we judged the certainty of the evidence to be low to very low overall; further research may change the findings. Our key outcomes of interest were: pain intensity, disability caused by pain, adverse events and psychological distress. Treatments varied in length, with the shortest being 4 weeks. The follow-up time ranged from 3 months to 12 months. Most studies evaluated CBT.   At treatment completion, there was no evidence of a benefit of CBT on pain intensity when measured against alternative treatment (standardised mean difference (SMD) 0.03, confidence interval (CI) -0.21 to 0.28; P = 0.79; 5 studies, 509 participants) or control (SMD -0.09, CI -0.30 to 0.12; P = 0.41; 6 studies, 577 participants). At follow-up, there was evidence of a small benefit of CBT for reducing pain intensity compared to alternative treatment (SMD -0.29, 95% CI -0.50 to -0.08; 5 studies, 475 participants) and control (SMD -0.30, CI -0.51 to -0.09; 6 studies, 639 participants). At treatment completion, there was no evidence of a difference in disability outcomes (interference in activities caused by pain) between CBT and alternative treatment (SMD 0.15, CI -0.40 to 0.10; P = 0.25; 3 studies, 245 participants), or between CBT and control/usual care (SMD 0.02, CI -0.21 to 0.24; P = 0.88; 3 studies, 315 participants). Nor was there evidence of a difference at follow-up (CBT versus alternative treatment: SMD -0.15, CI -0.42 to 0.12; 3 studies, 245 participants; CBT versus control: SMD 0.01 CI - 0.61 to 0.64; 2 studies, 240 participants). There were very few data on adverse events. From the data available, adverse effects associated with psychological treatment tended to be minor and to occur less often than in alternative treatment groups. There were, however, insufficient data available to draw firm conclusions. CBT showed a small benefit in terms of reducing psychological distress at treatment completion compared to alternative treatment (SMD -0.32, 95% CI -0.50 to -0.15; 6 studies, 553 participants), which was maintained at follow-up (SMD -0.32, 95% CI -0.51 to -0.13; 6 studies, 516 participants). For CBT versus control, only one study reported results for distress and did not find evidence of a difference between groups at treatment completion (mean difference (MD) 2.36, 95% CI -1.17 to 5.89; 101 participants) or follow-up (MD -1.02, 95% CI -4.02 to 1.98; 101 participants). We assessed the certainty of the evidence to be low or very low for all comparisons and outcomes. The data were insufficient to draw any reliable conclusions about psychological therapies other than CBT.

AUTHORS' CONCLUSIONS

We found mixed evidence for the effects of psychological therapies on painful temporomandibular disorders (TMDs). There is low-certainty evidence that CBT may reduce pain intensity more than alternative treatments or control when measured at longest follow-up,  but not at treatment completion. There is low-certainty evidence that CBT may be better than alternative treatments, but not control, for reducing psychological distress at treatment completion and follow-up. There is low-certainty evidence that CBT may not be better than other treatments or control for pain disability outcomes.  There is insufficient evidence to draw conclusions about alternative psychological therapeutic approaches, and there are insufficient data to be clear about adverse effects that may be associated with psychological therapies for painful TMD.  Overall, we found insufficient evidence on which to base a reliable judgement about the efficacy of psychological therapies for painful TMD. Further research is needed to determine whether or not psychological therapies are effective, the most effective type of therapy and delivery method, and how it can best be targeted. In particular, high-quality RCTs conducted in primary care and community settings are required, which evaluate a range of psychological approaches against alternative treatments or usual care, involve both adults and adolescents, and collect measures of pain intensity, pain disability and psychological distress until at least 12 months post-treatment.

How do psychologically based interventions for chronic musculoskeletal pain work? A systematic review and meta-analysis of specific moderators and mediators of treatment

Psychologically based interventions aim to improve pain-related functioning by targeting pain-related fears, cognitions and behaviors. Mediation and moderation analyses permit further examination of the effect of treatment on an outcome. This systematic review and meta-analysis aims to synthetize the evidence of specific mediators and moderators (i.e., treatment targets) of psychologically based treatment effects on pain and disability. A total of 28 mediation and 11 moderation analyses were included. Thirteen mediation studies were included in a meta-analysis, and the rest was narratively synthetized. Reductions in pain-related fear (indirect effect [IE]: -0.07; 95% confidence interval [CI]: -0.11, -0.04) and catastrophizing (IE: -0.07; 95%CI: -0.14, -0.00), as well as increases in self-efficacy (IE: -0.07; 95%CI: -0.11, -0.04), mediated effects of cognitive behavioral therapy on disability but not on pain intensity, when compared to control treatments. Enhancing pain acceptance (IE: -0.17; 95%CI: -0.31, -0.03) and psychological flexibility (IE: -0.30; 95%CI: -0.41, -0.18) mediated acceptance and commitment therapy effects on disability. The narrative synthesis showed conflicting evidence, which did not support a robust moderated effect for any of the examined constructs. Overall, the methodological quality regarding mediation was low, and some key pitfalls are highlighted alongside recommendations to provide a platform for future research.

Pain-related beliefs, cognitive processes, and electroencephalography band power as predictors and mediators of the effects of psychological chronic pain interventions

ABSTRACT

The current study used data from a clinical trial to identify variables that are associated with and/or mediate the beneficial effects of 4 psychological chronic pain treatments: one teaching patients self-hypnosis to reduce pain intensity (HYP), one teaching self-hypnosis to change thoughts about pain (hypnotic cognitive therapy [HYP-CT]), one teaching cognitive restructuring skills to change thoughts about pain (cognitive therapy [CT]), and one providing education about pain (ED; included as an active control condition). Of 17 possible mechanism variables examined, and with alpha not corrected for multiple comparisons, significant between-group differences were observed for 3. Two of these (changes in beliefs about control over pain and number of days of skill practice) were supported as mediators of the beneficial effects of HYP, CT, or HYP-CT, relative to ED. Six mechanism variables evidenced significant pretreatment to post-treatment changes in the sample as a whole, without showing significant between-group differences. Pretreatment to post-treatment changes in all 6 were associated with improvements in pain interference, pain intensity, or both. In addition, participant ratings of therapeutic alliance at post-treatment were associated significantly with improvements in both pain intensity and pain interference in the sample as a whole. Thus, of the 17 possible mediators examined, there were relatively few that served as mediators for the beneficial effects of specific treatments; a larger number of variables predicted treatment outcome overall. The extent to which these variables are treatment mediators (ie, are responsible for, rather than merely associated with, treatment-related improvements) will require further research.

The Relationship between Cognitive and Emotional Factors and Healthcare and Medication Use in People Experiencing Pain: A Systematic Review

Pain conditions are among the leading causes of global disability, impacting on global healthcare utilization (HCU). Health seeking behavior might be influenced by cognitive and emotional factors (CEF), which can be tackled by specific therapies. The purpose of this study was to systematically review the evidence concerning associations between CEF and HCU in people experiencing pain. Three databases were consulted: PubMed, Web of Science and EconLit. Risk of bias was assessed using the Downs and Black Checklist (modified). A total of 90 publications (total sample n = 59,719) was included after double-blind screening. In people experiencing pain, positive associations between general anxiety symptoms, depressive symptoms and catastrophizing and pain medication use were found. Additionally, there appears to be a relationship between general anxiety and depressive symptoms and opioid use. Symptom-related anxiety and psychological distress were found to be positively related with consulting behavior. Last, a positive association between use of complementary and alternative medicine and level of perceived symptom control was confirmed in people with pain. For other relationships no evidence or inconsistent findings were found, or they were insufficiently studied to draw firm conclusions, indicating that more research on this topic is needed.

Associations Between Sleep Disturbance and Chronic Pain Intensity and Function: A Test of Direct and Indirect Pathways

OBJECTIVES

Sleep disturbance and chronic pain are related. The present study evaluated both direct and indirect (mediated) pathways through which sleep disturbance might be related to chronic pain intensity and function.

METHODS

In total, 87 individuals (64% female) with chronic low back pain but not using opioids daily completed questionnaires assessing their sleep disturbance, chronic pain intensity, function, depression, anxiety, positive affect, and catastrophizing.

RESULTS

Greater sleep disturbance was associated with greater pain intensity, worse function, greater emotional distress, lower positive affect, and higher levels of catastrophizing. Cross-sectional mediation analyses revealed that the positive associations between sleep disturbance and chronic pain intensity were conveyed statistically not only by significant indirect effects of elevated emotional distress, lower positive affect, and greater catastrophizing associated with sleep disturbance, but also by significant direct effects of sleep disturbance on chronic pain intensity. Similarly, we found that the associations between sleep disturbance and impaired function were conveyed statistically not only by significant indirect effects of elevated chronic pain intensity associated with sleep disturbance, but also by significant direct effects of sleep disturbance on function.

DISCUSSION

Sleep disturbance was related significantly with chronic pain intensity and function by both direct and indirect pathways. These results are consistent with an emerging literature highlighting the potential significance of sleep disturbance in chronic pain patients, and provide further support for addressing sleep disturbance in the assessment and management of chronic pain.