Positive, but not negative, treatment outcome expectancies mediate the relation between depressive symptoms and treatment-related pain reduction.

Previous research has shown that depression is associated with adverse recovery outcomes following work-related musculoskeletal injury. Treatment outcome expectancies have also been shown to predict recovery trajectories following musculoskeletal injury. The present study examined the role of positive and negative treatment outcome expectancies as mediators of the relation between depressive symptoms and treatment outcome for individuals receiving physical therapy for a musculoskeletal injury. The study sample consisted of 153 individuals who had sustained a work-related musculoskeletal injury to the back or neck within 6 months of enrolment. Participants completed self-report measures of depressive symptom severity, pain severity, and treatment outcome expectancies prior to treatment; pain severity was assessed again after 4 weeks of treatment. The results of this study were consistent with previous research showing significant relations between depressive symptom severity, pain severity and treatment outcome expectancies. Bootstrapping mediation analyses separately assessed the mediating roles of positive and negative treatment outcome expectancies on the relation between depressive symptoms and pain severity. Findings revealed that positive treatment outcome expectancies mediated the relation between depressive symptoms and pain severity, whereas negative treatment outcome expectancies did not. Discussion addresses potential pathways through which positive treatment outcome expectancies might influence pain outcomes. The findings suggest that intervention techniques aimed at increasing positive treatment outcome expectancies, rather than decreasing negative treatment outcome expectancies, might contribute to better recovery outcomes for individuals experiencing pain and depressive symptoms following a work-related musculoskeletal injury.

Qualitative Examination of the Experience of Perceived Injustice Following Disabling Occupational Injury.

PURPOSE: The primary objective of this study was to explore individuals' perspectives on the factors, situations or events that contributed to their perceptions of injustice following occupational injury. MATERIALS AND METHODS: The study sample consisted of 30 participants (18 women, 12 men) who had submitted a time-loss claim for a work-related musculoskeletal injury. Participants with elevated scores on a measure of perceived injustice were interviewed about the factors that contributed to their sense of injustice. A thematic analysis was conducted to identify the broad classes of situations or events that participants experienced as unjust in the weeks following occupational injury. RESULTS: Three dominant themes emerged from the interviews: (1) Invalidation, (2) Undeserved suffering and (3) Blame. Inductively derived subthemes reflected specific dimensions of post-injury experiences that contributed to participants' sense of injustice. CONCLUSIONS: Given that suffering and invalidating communication are potentially modifiable factors, there are grounds for optimism that intervention approaches can be developed to prevent or reduce perceptions of injustice in the aftermath of debilitating injury. The development of intervention approaches that are effective in preventing or reducing perceptions of injustice holds promise of contributing to more positive recovery outcomes in individuals who have sustained debilitating work injuries.

Reductions in Fatigue Predict Occupational Re-engagement in Individuals with Work-Related Musculoskeletal Disorders.

Background Symptoms of fatigue have been shown to be associated with heightened levels of disability in patients suffering from a wide range of debilitating health and mental health conditions. The role of fatigue as a determinant of work disability in individuals with work-related musculoskeletal disorders (WRMD) has received little attention. The present study examined the role of fatigue as a determinant of work-disability in individuals with WRMDs. Methods Participants included 117 individuals with WRMDs who completed measures of pain severity, fatigue, depression and disability before and after participating in a behavioral activation rehabilitation intervention. Results Cross-sectional analyses on pre-treatment measures revealed that fatigue contributed significant variance to the prediction of self-reported disability, beyond the variance accounted for by pain severity and depression. Prospective analyses revealed that reductions in fatigue through the course of treatment predicted occupational re-engagement following termination of the intervention. Conclusions The results of the present study suggest fatigue contributes to occupational disability, independent of the effects of pain and depression. The findings also suggest that meaningful reductions in fatigue might be achieved through psychosocial interventions that promote gradual re-integration into discontinued activities, increase participants' exposure to success and achievement experiences, and reduce the severity of depressive symptoms. Behavioural activation interventions such as the one used in the present study might contribute to more positive occupational outcomes in work-disabled individuals who report high levels of fatigue.

The prognostic value of pain catastrophizing in health-related quality of life judgments after Total knee arthroplasty.

BACKGROUND: Total knee arthroplasty (TKA) is a highly effective procedure that yields reductions in pain and disability associated with end stage osteoarthritis (OA) of the knee. Quality of life instruments are frequently used to gauge the outcomes of total knee arthroplasty (TKA). However, research suggests that post-TKA reductions in symptom severity may not be the sole predictors of quality of life post-TKA. The primary objective of the present study was to examine the prognostic value of catastrophic thinking in health-related quality of life (HRQoL) judgments in patients with severe OA after TKA. METHODS: In this study we used a prospective cohort design to examine the value of pain catastrophizing in predicting HRQoL 1 year after TKA. Participants with advanced OA of the knee who were scheduled for TKA were recruited at one of three hospitals in Canada. The study sample consisted of 116 individuals (71 women, 45 men) who completed study questionnaires at their pre-surgical evaluation and 1 year after surgery. Hierarchical regression analysis was used to assess the unique contribution of pre-surgical pain catastrophizing to the prediction of post-surgical HRQoL judgments. RESULTS: The results of the hierarchical regression equation revealed that the overall model was significant, F (9,106) = 8.3, p < 001, and accounted for 36.4% of the variance in the prediction of post-surgical physical component score of HRQoL. Pain catastrophizing was entered in the last step of the equation and contributed significant unique variance (ß = -.35, p < .001) to the prediction of post-surgical physical component score of HRQoL above and beyond the variance accounted for by demographic variables, co-morbid health conditions, baseline HRQoL, and post-surgical reductions in pain, joint stiffness and physical disability. CONCLUSIONS: The current findings highlight the importance of pre-surgical catastrophic cognitions in influencing HRQoL judgments after TKA. The findings suggest that psychosocial interventions designed to reduce pain catastrophizing before TKA might contribute to better quality of life outcomes following surgery.

Sensitivity to Movement-Evoked Pain and Multi-Site Pain are Associated with Work-Disability Following Whiplash Injury: A Cross-Sectional Study.

Objectives Previous research has shown that sensitivity to movement-evoked pain is associated with higher scores on self-report measures of disability in individuals who have sustained whiplash injuries. However, it remains unclear whether sensitivity to movement-evoked pain is associated with work-disability. The aim of the present study was to examine the relation between sensitivity to movement-evoked pain and occupational status in individuals receiving treatment for whiplash injury. Methods A sample of 105 individuals with whiplash injuries participated in a testing session where different measures of pain (i.e. spontaneous pain, multi-site pain, sensitivity to movement-evoked pain) were collected during the performance of a simulated occupational lifting task. Results Hierarchical logistic regression analysis revealed that the measures of multisite pain and sensitivity to movement-evoked pain made significant independent contributions to the prediction of work-disability. Discussion The findings suggest that including measures of multisite pain and sensitivity to movement evoked pain in assessment protocols has the potential to increase the value of pain assessments for the prediction of occupational disability associated with whiplash injury. Clinical and theoretical implications of the findings are addressed.

The Mediating Role of Recovery Expectancies on the Relation Between Depression and Return-to-Work.

PURPOSE: Depressive symptoms have been identified as a significant risk factor for prolonged disability, however, little is known about the process by which depression impacts recovery following work-related musculoskeletal disorders (WRMDs). The primary objective of this study was to examine whether recovery expectancies mediate the relation between depression and return-to-work (RTW) status in individuals with WRMDs. METHODS: A sample of 109 patients with WRMDs were recruited from 1 of 6 primary care physiotherapy clinics. Participants completed measures of pain severity, depression and recovery expectancies. RTW status was assessed by telephone interview 1 year after the initial assessment. RESULTS: Consistent with previous research, more severe depressive symptoms and lower recovery expectancies were associated with a lower probability of RTW. Logistic regression analyses revealed that recovery expectancies completely mediated the relation between depression and RTW status at 1-year follow-up. CONCLUSION: The results suggest that interventions specifically targeting recovery expectancies in individuals with WRMDs and depressive symptoms might improve RTW outcomes.

Rates and Correlates of Unemployment Across Four Common Chronic Pain Diagnostic Categories.

PURPOSE: To examine rates and correlates of unemployment across distinct common chronic pain diagnoses. METHODS: Data were analyzed from a sample of 2,382 patients with chronic pain in the Quebec Pain Registry (QPR). Patients were grouped into the following diagnostic categories based on their primary pain diagnosis recorded in the QPR: musculoskeletal pain; myofascial pain; neuropathic pain, and visceral pain. Analyses were performed to examine the associations between pain diagnosis, patient demographics, pain intensity, depressive symptoms, and unemployment status. RESULTS: Pain diagnosis, age, marital status, education, pain intensity, and depressive symptoms were each significant unique predictors of unemployment status in a hierarchical logistic regression analysis; the addition of depressive symptoms in this model contributed to the greatest increment of model fit. CONCLUSIONS: Depressive symptoms are associated with unemployment across a number of common chronic pain conditions, even when controlling for other factors that are associated with unemployment in these patients. Depressive symptoms, as a modifiable factor, may thus be an important target of intervention for unemployed patients with chronic pain.

Pain Catastrophizing: Controversies, Misconceptions and Future Directions.

Recent reports have pointed to problems with the term "pain catastrophizing." Critiques of the term pain catastrophizing have come from several sources including individuals with chronic pain, advocates for individuals with chronic pain, and pain scholars. Reports indicate that the term has been used to dismiss the medical basis of pain complaints, to question the authenticity of pain complaints, and to blame individuals with pain for their pain condition. In this paper, we advance the position that the problems prompting calls to rename the construct of pain catastrophizing have little to do with the term, and as such, changing the term will do little to solve these problems. We argue that continued calls for changing or deleting the term pain catastrophizing will only divert attention away from some fundamental flaws in how individuals with pain conditions are assessed and treated. Some of these fundamental flaws have their roots in the inadequate training of health and allied health professionals in evidence-based models of pain, in the use of psychological assessment and intervention tools for the clinical management of pain, and in gender equity and antiracism. Critiques that pain scholars have leveled against the defining, operational, and conceptual bases of pain catastrophizing are also addressed. Arguments for reconceptualizing pain catastrophizing as a worry-related construct are discussed. Recommendations are made for remediation of the problems that have contributed to calls to rename the term pain catastrophizing. PERSPECTIVE: The issues prompting calls to rename the construct of pain catastrophizing have their roots in fundamental flaws in how individuals with pain are assessed and treated. Efforts to address these problems will require more than a simple change in terminology.

Temporal Relations Between Pain Catastrophizing and Adverse Health and Mental Health Outcomes After Whiplash Injury.

OBJECTIVES: Pain catastrophizing has been shown to be a prognostic indicator for pain severity and the co-occurrence of mental health conditions such as depression and post-traumatic stress disorder after whiplash injury. However, the pattern of available findings is limited in its implications for the possible "antecedent" or "causal" role of pain catastrophizing. The purpose of the present study was to examine the temporal relations between pain catastrophizing, pain severity, depressive symptoms, and post-traumatic stress symptoms (PTSS) in individuals receiving treatment for whiplash injury. MATERIALS AND METHODS: The sample consisted of 388 individuals enrolled in a multidisciplinary program for whiplash injury. Participants completed self-report measures of pain catastrophizing, pain severity, depressive symptoms, and PTSS at the time of admission, mid-treatment (4 week), and treatment completion (7 week). A cross-lagged panel analysis was used to examine the temporal relations between pain catastrophizing, pain severity, depressive symptoms, and PTSS across all 3 timepoints. RESULTS: Model fit was acceptable after the inclusion of modification indices. Pain catastrophizing at the time of admission predicted all other variables at 4 weeks. Pain catastrophizing at 4 weeks also predicted all other variables at 7 weeks. In addition, some bidirectional relations were present, particularly for variables assessed at week 4 and week 7. DISCUSSION: Findings support the view that pain catastrophizing might play a transdiagnostic role in the onset and maintenance of health and mental health conditions. The findings call for greater emphasis on the development of treatment techniques that target pain catastrophizing in intervention programs for whiplash injury.

Further validation of a measure of injury-related injustice perceptions to identify risk for occupational disability: a prospective study of individuals with whiplash injury.

PURPOSE: Emerging evidence suggests that perceptions of injustice negatively impact return to work following whiplash injury. The Injustice Experiences Questionnaire (IEQ) is a recently developed measurement tool that may be used to assess injury-related perceptions of injustice following injury. To date, although research has supported the predictive validity of the IEQ, a clinical cut off for interpreting this measure has not been established. Increased support for the validity and clinical interpretation of the IEQ represents a first step towards identifying patients that might benefit from targeted intervention to mitigate the impact of perceived injustice. METHODS: The IEQ was completed by 103 whiplash-injured patients upon commencement and completion of a standardized multidisciplinary rehabilitation program. One year later, individuals reported on their employment activity, pain severity, and use of narcotics. A receiver operating characteristic (ROC) curve analysis was conducted to identify the post-treatment IEQ score that was optimally associated with unemployment status at the follow-up. Secondary ROC curve analyses examined IEQ scores best associated with high pain severity and narcotic use 1 year following treatment. RESULTS: Results indicated that IEQ scores significantly discriminated individuals who returned and did not return to work at the follow-up. An IEQ score of 19 optimally identified participants in terms of follow-up employment status. IEQ scores at the end of treatment also discriminated individuals with high and low pain severity ratings and narcotic use status at the follow-up. Post-treatment IEQ scores of 18 and 20 optimally identified participants who had high pain severity ratings and who were using narcotics at the follow-up, respectively. CONCLUSIONS: These results further support the validity of the IEQ and provide a guideline for its clinical interpretation in patients with persistent pain and disability following musculoskeletal injury. IEQ scores above the identified cut off may represent a barrier to work return and may warrant targeted intervention.

Establishing the Reliability, Validity, and Prognostic Utility of the Momentary Pain Catastrophizing Scale for Use in Ecological Momentary Assessment Research.

Despite the marked increase in ecological momentary assessment research, few reliable and valid measures of momentary experiences have been established. The goal of this preregistered study was to establish the reliability, validity, and prognostic utility of the momentary Pain Catastrophizing Scale (mPCS), a 3-item measure developed to assess situational pain catastrophizing. Participants in 2 studies of postsurgical pain outcomes completed the mPCS 3 to 5 times per day prior to surgery (N = 494, T = 20,271 total assessments). The mPCS showed good psychometric properties, including multilevel reliability and factor invariance across time. Participant-level average mPCS was strongly positively correlated with dispositional pain catastrophizing as assessed by the Pain Catastrophizing Scale (r = .55 and .69 in study 1 and study 2, respectively). To establish prognostic utility, we then examined whether the mPCS improved prediction of postsurgical pain outcomes above and beyond one-time assessment of dispositional pain catastrophizing. Indeed, greater variability in momentary pain catastrophizing prior to surgery was uniquely associated with increased pain immediately after surgery (b = .58, P = .005), after controlling for preoperative pain levels and dispositional pain catastrophizing. Greater average mPCS score prior to surgery was also uniquely associated with lesser day-to-day improvement in postsurgical pain (b = .01, P = .003), whereas dispositional pain catastrophizing was not (b = -.007, P = .099). These results show that the mPCS is a reliable and valid tool for ecological momentary assessment research and highlight its potential utility over and above retrospective measures of pain catastrophizing. PERSPECTIVE: This article presents the psychometric properties and prognostic utility of a new measure to assess momentary pain catastrophizing. This brief, 3-item measure will allow researchers and clinicians to assess fluctuations in pain catastrophizing during individuals' daily lives, as well as dynamic relationships between catastrophizing, pain, and related factors.

Risk-targeted behavioral activation for the management of work disability associated with comorbid pain and depression: a feasibility study.

PURPOSE: The purpose of the present study was to conduct a preliminary evaluation of the feasibility and impact of a risk-targeted behavioral activation intervention for work-disabled individuals with comorbid pain and depression. METHODS: The design of the study was a single-arm non-randomized trial. The sample consisted of 66 work-disabled individuals with comorbid pain and depression. The treatment program consisted of a 10-week standardized behavioral activation intervention supplemented by techniques to target two psychosocial risk factors for delayed recovery, namely, catastrophic thinking and perceptions of injustice. Measures of pain severity, depression, catastrophic thinking, perceived injustice, and self-reported disability were completed pre-, mid-, and post-treatment. Satisfaction with treatment was assessed at post-treatment. Return to work was assessed at 6-month follow-up. RESULTS: The drop-out rate was 18%. At treatment termination, 91% of participants indicated that they were "very" or "completely" satisfied with their involvement in the treatment program. Significant reductions in pain (Cohen's d = 0.71), depression (d = 0.86), catastrophic thinking (d = 1.1), and perceived injustice (d = 1.0) were observed through the course of treatment. In multivariate analyses, treatment-related reductions in depression, catastrophic thinking, and perceived injustice, but not pain, contributed significant unique variance to the prediction of return-to-work outcomes. CONCLUSIONS: Risk-targeted behavioral activation was found to be an acceptable and effective intervention for work-disabled individuals with comorbid pain and depression. The findings suggest that interventions targeting psychosocial risk factors for pain and depression might contribute to more positive recovery outcomes in work-disabled individuals with comorbid pain and depression. TRIAL REGISTRATION: ClinicalTrials.gov: NCT0517442 . Retrospectively registered.

Pain Medication Beliefs Mediate the Relationship Between Pain Catastrophizing and Opioid Prescription Use in Patients With Chronic Non-Cancer Pain.

Little is known about the mechanisms by which pain catastrophizing may be associated with opioid use outcomes. This study aimed to investigate the potential mediating role of beliefs about the appropriateness of pain medicines for pain treatment on the association between pain catastrophizing and prescription opioid use in a community chronic non-cancer pain (CNCP) sample. Individuals (N = 420) diagnosed with CNCP participated in a cross-sectional online self-report study with validated measures of pain medication beliefs, pain catastrophizing, and current prescription opioid use. Two parallel multiple mediator analyses with percentile-based bootstrapping examined pathways to both prescription opioid use and high-dose use (≥ 100mg oral morphine equivalents/day), while controlling for pain intensity and other relevant covariates. Pain medication beliefs significantly mediated the association between pain catastrophizing and prescription opioid use (CI = 0.011, 0.033). A similar pattern of findings was found for high-dose opioid use, with pain medication beliefs significantly mediating the pain catastrophizing-high-dose use association (CI = 0.006, 0.050). Pain medication beliefs are a potentially modifiable psychological mechanism by which pain catastrophizing is associated with opioid use, including high-dose use. These findings have important implications for personalizing prevention and treatment programs.

Improving well-being for individuals with persistent pain after surgery for breast cancer, lobular carcinoma in situ, or ductal carcinoma in situ: A randomized clinical trial.

>276,000 Americans will be diagnosed with invasive breast cancer, lobular carcinoma in situ, or ductal carcinoma in situ this year and most will undergo breast surgery as part of their care. Although prognosis is excellent, many patients experience persistent post-surgical pain (PSP), which has no satisfactory pharmacological treatment. The causal contributions of pain-associated psychological factors (e.g., catastrophic thoughts about pain, psychological flexibility, self-efficacy) to the continuing burden of PSP have not yet been determined and may be opportune intervention targets. The randomized trial described here will compare the benefits of three manualized behavioral interventions for individuals with PSP. Participants will receive either: 1) self-guided health education (SGHE); 2) interventionist-guided health education (IGHE); or 3) interventionist-guided pain coping skills training with elements of acceptance and commitment therapy that specially target catastrophic thoughts about pain, self-efficacy, and psychological flexibility (CST-PSP). Participants will prospectively complete validated assessments of primary outcomes (PSP severity and interference) at baseline (pre-intervention) and 3-, 6-, and 12-months later. Validated measures of emotional distress and cancer-specific distress will be assessed as secondary outcomes. To test their roles as drivers of PSP, catastrophic thoughts about pain, self-efficacy, and psychological flexibility, will be assessed and statistically analyzed as mediators of hypothesized beneficial effects. The interventions' impacts on pain sensitivity and central sensitization will be investigated to test these physiological pathways as proximal drivers of PSP. To better characterize the patient experience, additional validated measures will be explored for associations with PSP, along with demographic and clinical factors. Trial registration: https://clinicaltrials.gov/ct2/show/NCT04225585, registered January 13, 2020.

Catastrophizers with chronic pain display more pain behaviour when in a relationship with a low catastrophizing spouse.

The present study examined the relationship between couple concordance of catastrophizing and adverse pain outcomes. Possible mechanisms underlying the relationship between couple concordance of catastrophizing and pain outcomes were also explored. Fifty-eight couples were recruited for the study. The chronic pain patients were filmed while lifting a series of weighted canisters. The spouse was later invited to view the video and answer questions about the pain experience of their partner. Median splits on Pain Catastrophizing Scale scores were used to create four 'catastrophizing concordance' groups: low catastrophizing patient-low catastrophizing spouse; low catastrophizing patient-high catastrophizing spouse; high catastrophizing patient-low catastrophizing spouse; and high catastrophizing patient-high catastrophizing spouse. Analyses revealed that high catastrophizing pain patients who were in a relationship with a low catastrophizing spouse displayed more pain behaviours than patients in all other groups. These findings suggest that high catastrophizing chronic pain patients may need to increase the 'volume' of pain communication to compensate for low catastrophizing spouses' tendency to underestimate the severity of their pain experience. Patients' perceived solicitousness and punitive response from the spouse could not explain the group differences in pain behaviour. Theoretical and clinical implications of the findings are discussed.

The Prospective Prognostic Value of Biopsychosocial Indices of Sensitivity to Physical Activity Among People With Back Pain.

OBJECTIVES: Many people living with musculoskeletal pain conditions experience a range of negative biopsychosocial responses to physical activity, referred to as increased sensitivity to physical activity (SPA), that may undermine successful rehabilitation. This exploratory study aims to provide the first prospective analysis of the potential prognostic value of 3 biopsychosocial indices of SPA in relation to rehabilitation outcomes. This study also aimed to shed light on the cross-sectional interrelationships between these 3 biopsychosocial indices of SPA. MATERIALS AND METHODS: Adults with back pain were evaluated upon starting physical therapy and then again 3 months later. The initial testing session consisted of self-reported pain-related questionnaires and assessment of activity-related changes in pressure pain thresholds (SPA-Sensory), pain intensity ratings (SPA-Pain), and situational catastrophizing (SPA-Psych). The 3-month follow-up consisted of self-reported disability and pain questionnaires. Correlational and hierarchical linear regression analyses were conducted. RESULTS: A total of 97 participants completed both the initial visit and 3-month follow-up. The SPA-Pain index and the SPA-Psych index were significantly intercorrelated, but neither were correlated with the SPA-Sensory index. The SPA-Sensory index was not correlated with outcomes. The SPA-Pain index was correlated only with cross-sectional disability and pain outcomes. The SPA-Psych index was the only SPA index significantly correlated with outcomes both cross-sectionally and at 3-month follow-up. After controlling for baseline pain/disability and pain catastrophizing, SPA-Psych was no longer a significant prognostic factor for pain, but remained a significant prognostic factor for disability at 3-month follow-up (ß=0.272, t=2.674, P=0.008, R2 Δ=5.60%). DISCUSSION: This study highlights the importance of conceptualizing and measuring SPA as a biopsychosocial (rather than unidimensional) construct and points toward the added prognostic value of this construct. Implications for future research and practice are discussed.

Directed attention alters the temporal activation patterns of back extensors during trunk flexion-extension in individuals with chronic low back pain.

In chronic low back pain patients (CLBP), neuromuscular and pain intensity have been identified as contributing factors in the disability of the individual. However, it is unclear whether pain intensity influences neuromuscular activation and if directed attention mediates this relationship. Thus, the purpose of this study was to determine the effect of directed attention in individuals with different pain intensities on back extensor activation profiles. Fifty-four CLBP patients were separated into either high- or low-pain groups. Surface electromyograms were recorded from back muscles while the subjects performed a trunk flexion motion for four different attention conditions. Pattern recognition and repeated measures ANOVAs were used to examine the effect of sex, attention and pain intensity on temporal muscle activation patterns. The results showed that there was a significant sex x attention x pain interaction. The largest changes in muscle timing were observed in the low-pain group when their attention was focused on their pain, but the pattern of muscle activation differed between sexes. For males, a rapid decline in activation at mid-extension occurred, whereas females showed delayed activation at the beginning of extension. Overall, this study demonstrated that directed attention on pain had an effect on trunk muscle temporal recruitment, and that this relationship differed between sexes and pain groups. This suggests that sex-specific mechanisms may alter the neuromuscular control of the spine in CLBP patients for different pain levels.

The relation between perceived injustice and symptom severity in individuals with major depression: A cross-lagged panel study.

BACKGROUND: Perceived injustice has been associated with problematic recovery outcomes in individuals with debilitating health conditions. However, the relation between perceived injustice and recovery outcomes has not been previously examined in individuals with debilitating mental health conditions. The present study examined the relation between perceived injustice and symptom severity in individuals undergoing treatment for Major Depressive Disorder (MDD). METHODS: The study sample consisted of 253 work-disabled individuals with MDD who were referred to an occupational rehabilitation service. Participants completed measures of depressive symptom severity, perceived injustice, catastrophic thinking, pain and occupational disability at three time-points (pre-, mid- and post-treatment) during a 10-week behavioural activation intervention. RESULTS: Regression analysis on baseline data revealed that perceived injustice contributed significant variance to the prediction of depressive symptom severity, beyond the variance accounted for by time since diagnosis, pain severity and catastrophic thinking. Prospective analyses revealed that early treatment reductions in perceived injustice predicted late treatment reductions in depressive symptom severity. LIMITATIONS: The study sample consisted of work-disabled individuals with MDD who had been referred to an occupational rehabilitation service. This selection bias has implications for the generalizability of findings. CONCLUSION: The findings suggest that perceived injustice is a determinant of symptom severity in individuals with MDD. The inclusion of techniques designed to reduce perceived injustice might augment positive treatment outcomes for individuals receiving treatment for MDD.

The Relationship Between Level of Catastrophizing and Mental Health Comorbidity in Individuals With Whiplash Injuries.

OBJECTIVES: Pain catastrophizing has been shown to be correlated with measures of mental health problems such as depression and post-traumatic stress disorder (PTSD). However, the clinical implications of findings reported to date remain unclear. To date, no study has been conducted to determine meaningful cut-scores on measures of catastrophizing indicative of the heightened risk of mental health comorbidity. One objective of the present study was to identify the cut-score on the Pain Catastrophizing Scale (PCS) indicative of the heightened risk of the comorbidity of depression and PTSD. A second objective was to determine whether mental health comorbidity mediated the relationship between catastrophizing and occupational disability. MATERIALS AND METHODS: The sample consisted of 143 individuals with whiplash injuries. Pain severity, pain catastrophizing, depression, and post-traumatic stress symptoms were assessed after admission to a rehabilitation program. Mental health comorbidity was operationally defined as obtaining a score above the clinical threshold on measures of depressive and/or post-traumatic stress symptom severity. RESULTS: A receiver operating characteristic curve analysis revealed that a PCS score of 22 best distinguished between participants with and without mental health comorbidity. Results also revealed that mental health comorbidity mediated the relationship between catastrophizing and occupational disability. DISCUSSION: The findings suggest that a score of ≥22 on the PCS should alert clinicians to the possibility that patients might also be experiencing clinically significant symptoms of depression or PTSD. Greater attention to the detection and treatment of mental health conditions associated with whiplash injury might contribute to more positive recovery outcomes.