Mild Depression in Low Back Pain: the Interaction of Thought Suppression and Stress Plays a Role, Especially in Female Patients.

PURPOSE: Mild depression has been shown as a precursor and as a consequence of low back pain, even in early phases of acute or subacute pain. Chronic daily life stress as well as dysfunctional pain-related cognitions such as thought suppression (TS) seem to play a role in the pain-depression cycle; however, the mechanisms of these associations are less understood. Experimentally induced TS, conceived as the attempt to directly suppress sensations such as pain, has been shown to paradoxically cause a delayed and non-volitional return of the suppressed thoughts and sensations and to increase affective distress. These dysfunctional processes are supposed to increase under high cognitive load, such as high stress. METHOD: In the present cross-sectional study, we for the first time sought to examine a possible interaction between habitual TS and stress on depression in N = 177 patients with subacute low back pain (SLBP), using the following questionnaires: Subscale Thought Suppression from Avoidance-Endurance Questionnaire, Beck Depression Inventory, and Kiel Interview of Subjective Situation. A three-way ANOVA was conducted with two groups of TS (high/low), stress (high/low) and sex as independent factors and depression as dependent. RESULTS: Results indicated a significant three-way interaction with highest depression scores in female patients showing high TS and high stress. Overall main effects for sex and stress indicated higher depression in women and in highly stressed patients. CONCLUSION: Our findings support the hypothesis that TS heightens depressive mood under conditions of high cognitive load especially in female patients with SLBP indicating a special vulnerability for depressive mood in women with SLBP.

Correction to: Mild Depression in Low Back Pain: the Interaction of Thought Suppression and Stress Plays a Role, Especially in Female Patients.

This article was updated to correct the author names. Family and given names are in the correct order.

Isometric Back Exercise Has Different Effect on Pressure Pain Thresholds in Healthy Men and Women.

Objective: Isometric exercises produce an acute decrease in the pain sensitivity, known as exercise-induced hypoalgesia (EIH). Existing EIH paradigms use exercises at the extremities with more pronounced EIH at local compared to remote body sites, indicating local inhibition in addition to central inhibitory mechanisms. So far the results on EIH in patients with low back pain (LBP) are equivocal and no studies have investigated an EIH paradigm targeting the lower back in order to assess EIH in patients with LBP. Thus, the aim of this pilot study was to assess pressure pain sensitivity at local and remote assessment sites, before and after an isometric back exercise in healthy women and men. Methods: In a pre-posttest design, pressure pain thresholds (PPT) were assessed at the lower back, biceps femoris muscle, and hand in 29 healthy subjects (17 women) before and after 120 seconds of the isometric Biering-Soerensen back extension test. Results: After exercise, PPT increased significantly at the hand in women, but not in men ( P = 0.027). Moreover, PPT at the leg increased independently of sex ( P < 0.004). The increase in PPT at the lower back after exercise approached significance ( P = 0.07). Conclusions: The results of this pilot study indicate that isometric back exercise produces local and remote hypoalgesia. Remote EIH was only demonstrated in women, supporting the influence of sex in the hypoalgesic response after exercise. The effect of isometric back exercise on pain sensitivity in patients with low back pain should be investigated in future studies.

Recall Bias in Patients with Chronic Low Back Pain: Individual Pain Response Patterns Are More Important Than Pain Itself!

BACKGROUND: Patients' cognitive processing of pain-related information as well as their cognitive, affective and behavioral response pattern when experiencing pain in daily life has been shown to be associated with poorer prognosis in low back pain. However, the relationship between specific cognitive processes such as recall of pain-related material and individual pain responses remains unknown. PURPOSE: The present study sought to investigate recall bias in patients with chronic low back pain (CLBP) compared to healthy controls. Furthermore, it was aimed to investigate the impact of patients' individual pain-related responses on recall bias, comparing fear-avoidance response (FAR), endurance response (ER) and adaptive response (AR) patterns. METHOD: Thirty-one CLBP patients and 31 controls were tested on a free recall task with three word lists comprising pain words and neutral words. Further, the CLBP group was classified into patients with a FAR, ER and AR pattern, using a short screening including the Avoidance-Endurance Questionnaire (AEQ). Group differences with pain status (CLBP vs. healthy) and AEQ responses (FAR, ER, AR) as between-group factors, word type (pain vs. neutral) as within-group factor and free recall as dependent variable were analysed by means of repeated-measures analysis of (co-) variance. RESULTS: Results revealed different pain processing of pain words between FAR and ER patterns, whereas CLBP patients as a whole did not differ from the healthy controls. FAR patients displayed significantly less recall than ER patients. CONCLUSION: Recall biases in CLBP patients are not only a result of experiencing pain but also effected by patients' pain response pattern with respect to fear-avoidance versus endurance.

Comparing the Effects of Thought Suppression and Focused Distraction on Pain-Related Attentional Biases in Men and Women.

Increasing attentional focus away from pain can affect pain experience, suggesting that cognitive strategies that move attentional allocation may be a moderator of pain. In a pre-post-design, the present study examined the effects of 2 cognitive strategies used in pain contexts, thought suppression and focused distraction, on subsequent pain-related attention. Thought suppression was hypothesized to increase pain-related attention, whereas focused distraction was expected to reduce it. Influences of both anxiety and sex were also considered, as secondary questions. 139 (86 women, 53 men) healthy, pain-free participants were randomly assigned to use either thought suppression or focused distraction during a mild cold pressor test (CPT). Pain-related attention was examined using a dot-probe and an attentional blink task, pre-and post-CPT. Questionnaires about relevant cognitive and emotional aspects, demographics, and pain were completed. Results showed no difference in the effect of the 2 pain inhibition strategies on pain-related attention. The hypothesized rebound effect in thought suppression on pain-related attention did not emerge. However, thought suppression showed a short-term benefit in comparison to focused distraction regarding reported pain and perceived threat during the cold pressor test. Few sex differences were found. Thus, the cognitive strategies affected pain outcomes, but did not influence pain-related attention. PERSPECTIVE: Cognitive strategies could help with pain through changing attention allocation. In this study, the effects of the 2 cognitive strategies thought suppression and focused distraction on pain-related attention in men and women were examined. Elucidating mechanisms that lie behind pain strategies that focus on changing attention may help improve treatments.

Depression and suicidal ideation in high-performance athletes suffering from low back pain: The role of stress and pain-related thought suppression.

BACKGROUND: Depression and suicidal ideation are important health problems in athletes suffering from pain. Dysfunctional pain cognitions, that is, pain-related thought suppression (PTS), may play an important role in their aetiology. Thought suppression was shown to increase depressive mood, particularly in highly stressed individuals. This cross-sectional study examines the relationship between PTS and stress on depression and suicidal ideation in athletes with pain. METHODS: A total of 159 athletes with non-specific low back pain completed a set of questionnaires to measure PTS, depression and stress. Participants were split into groups with high and low stress, and high and low PTS. Two-way ANOVA calculated main effects for PTS, stress and a PTS*stress interaction, with depressive symptoms as dependent. Subsequently, distribution tests were calculated, investigating if the presence of clinically relevant depression and suicidal ideation is dependent of conditions of high/low PTS and stress. RESULTS: A main effect of stress demonstrated higher depression scores in highly stressed athletes. Further, a significant PTS*stress interaction showed elevated depression scores in athletes with high PTS and high stress. Distribution analysis revealed positive associations between PTS, stress and depression, with depression being most frequent among athletes with high PTS and high stress. Suicidal ideation was not significantly associated with PTS and only weakly correlated with stress. CONCLUSIONS: Our findings show that PTS is the most common pain response in athletes with pain. The results indicate a higher prevalence of depression and elevated depressive symptoms in athletes experiencing high stress, seemingly more pronounced when highly engaging in PTS. SIGNIFICANCE: This study contributes to the understanding of depression in athletes with pain, suggesting stress and pain-related thought suppression to increase symptoms and prevalence of depression. As athletes often experience acute or chronic pain, understanding the impact of pain cognitions on health outcomes is an important step in the optimization of treatments.

Psychological pain responses in athletes and non-athletes with low back pain: Avoidance and endurance matter.

BACKGROUND: Dysfunctional psychological pain responses, namely fear-avoidance (FAR), including catastrophizing and helplessness, as well as endurance-related responses (ER), including thought suppression and overactivity, have been shown to be risk factors for persistent low back pain (LBP). Literature suggests that athletes may differ from non-athletes regarding psychological responses to pain. OBJECTIVES: This study set out to compare FAR and ER between athletes and non-athletes with LBP. It was hypothesized that athletes would report less frequent FAR and more frequent ER, and that both FAR and ER are associated with LBP intensity and disability. METHODS: The 173 athletes and 93 non-athletes cross-sectionally reported how frequently they employ FAR and ER on the Avoidance-Endurance Questionnaire (AEQ), as well as LBP intensity and disability on the Chronic Pain Grade Questionnaire (CPGS). MANOVA was applied to compare FAR and ER between athletes and non-athletes. Hierarchical multiple linear regression models were used to determine the unique associations between FAR and ER with LBP intensity and disability. RESULTS: Athletes reported lower frequencies of behavioural avoidance than non-athletes, but no other FAR variables differed between the groups. Frequencies of ER did not differ between athletes and non-athletes. Regression analysis indicated substantial associations of FAR with LBP intensity, as well as of FAR and ER with disability in athletes and non-athletes. CONCLUSIONS: The results of the present study suggest that athletes and non-athletes with LBP differ regarding behavioural avoidance, but overall, differences regarding pain responses are marginal. FAR and ER are both reported in athletes and non-athletes and contribute to disability in both groups. SIGNIFICANCE: Athletes train to endure pain in the course of athletic socialization, at least in the context of exercise. However, there is sparsity of knowledge about psychological pain responses in athletes with low back pain and whether they differ from those in non-athletes. The results of this comparative study suggest that endurance responses are more frequent than avoidance responses among athletes and non-athletes alike. However, both types of responses seem relevant to clinical pain management in athletes as well as non-athletes.

The relationship between activity and pain in patients 6 months after lumbar disc surgery: do pain-related coping modes act as moderator variables?

BACKGROUND: In LBP patients, the relationship between pain and physical activity remains unclear. Whereas a negative relationship between pain and self-reported physical activity was found, this relation disappeared in the case of overt behavioral data (e.g., accelerometer). Cognitive-behavioral models of the development of chronic pain suggest subgroups with signs of physical underuse and overuse. AIMS: To examine if patients with pain-related adaptive, endurance and fear-avoidance coping differ in pain, self-reported physical function and overt physical activity 6 months after disc surgery. METHODS: 24 patients completed questionnaires (Von Korff chronic pain grade (CPG), Kiel pain inventory (KPI), Funktionsfragebogen Hannover-Rücken FFbH-R) and underwent an 8-h accelerometer assessment in their daily life (physical activity level (PAL), number of constant postures (CP)). The KPI differed between adaptive coping (AC) (N=9), fear avoidance coping (FAC) (N=1) and endurance coping (EC) (N=14). RESULTS: In the whole group, pain intensity was negative related to self-reported physical activity whereas PAL and CP displayed no correlation with pain. EC patients showed significantly higher pain scores and lower self-reported physical functioning compared to AC but the same level of PAL and furthermore, a significantly higher number of CPs in daily life. The visual inspection of the FAC patient revealed also high pain, low physical functioning and low overt physical activity. CONCLUSIONS: The assessment of pain-related coping modes yielded an important differentiation between subgroups of LBP patients 6 months after surgery. Endurance copers displayed signs of overuse in their daily behavior in spite of pain than adaptive copers. The one fear avoidance coper tends to do less physical activity in the sense of underuse.