Quality of life in major depressive disorder: the role of pain and pain catastrophizing cognition

A control study on pain characteristics and influencing factors in patients with depressive disorders-based on a 5-year follow-up report from the epidemiological survey of mental disorders in Shandong Province, China

BACKGROUND

This study extends from the 2015 Shandong Province Epidemiological Survey of Mental Disorders in adults aged 18 and above. Over five years, it investigates pain characteristics and influencing factors in individuals with depressive disorders in Shandong Province.

METHODS

The study encompasses 871 individuals who met DSM-IV criteria for depressive disorders in 2015. Using 1:1:1 matching by gender, age, and residence, 825 non-afflicted individuals were selected as high-risk controls, and 825 screening-negative individuals became low-risk controls. A follow-up study in 2020 involved 1848 participants. Survey tools included a general information questionnaire, General Health Questionnaire-12 (GHQ-12), SCID-I/P, Global Pain Scale (GPS), Quality of Life Questionnaire (QLQ), PSQI, MoCA, and clinical data questionnaire.

RESULTS

GPS scores in the current depressive group were higher than in non-current depressive group (Z = 14.36, P < 0.01). GPS scores in study group exceeded those in high-risk and low-risk control groups (H = 93.71, P < 0.01). GPS scores in non-remission group were higher than in the remission group (Z = 8.90, P < 0.01). Regression analysis revealed positive correlations between GPS scores and physical illnesses, current depression, incumbency, GHQ-12 total score, and PSQI total score. Negative correlations were observed with QLQ total score and MoCA total score.

LIMITATIONS

The study could not assess pain during the 2015 survey, limiting controlled pain analysis before and after five years.

CONCLUSION

Depression sufferers may experience prolonged heightened pain, potentially relieved when depression subsides. Individual pain is influenced by depression, physical illnesses, sleep quality, quality of life, cognitive function, gender, residence, and occupation.

Predictors of Changes in Quality of Life of Patients with Major Depressive Disorder-A Prospective Naturalistic 3-Month Follow-Up Study

Major depressive disorder (MDD) is one of the leading causes of disease burden worldwide and affected patients frequently report impairments in quality of life (QoL). Therefore, the present research aimed to identify predictors of domain-specific QoL changes in MDD patients following the acute phase of pharmacological treatment (3-month). This study is a prospective, naturalistic, and observational analysis on 150 patients. Depressive symptoms, QoL, overall pain intensity, and functionality were assessed using Hamilton Depression Rating Scale, World Health Organization Quality of Life scale-abbreviated version, Visual Analog Scale, and Sheehan Disability Scale, respectively. Reductions in symptom severity and disability were predictors of improvement across all domains of QoL. Pain intensity reduction was a predictor of increases in the physical aspect of QoL. A reduced number of psychiatric hospitalizations and being in a relationship predicted an improvement of QoL in the psychological domain whereas a positive history of suicidal attempts was associated with better social relationships QoL. The predictive models explained 41.2% and 54.7% of the variance in psychological and physical health domains of QoL, respectively. Awareness of sociodemographic and changes in clinical factors that impact the change in domain-specific QoL might help in shaping personalized treatment.

The role of maladaptive emotion regulation in the bidirectional relation between sleep and depression in college students during the COVID-19 pandemic

Background: Emotion regulation deficits are an outcome and risk factor for both insomnia and depression, suggesting that maladaptive emotion regulation might in part explain the bi-directional links between sleep and depression. The current study tests this hypothesis during the COVID-19 pandemic in emerging adult undergraduate students, a high-risk population for both depression and sleep disturbance.Methods: A sample of 154 undergraduate students completed a series of online questionnaires bi-weekly on sleep, depression, and emotion regulation strategies across eight weeks during the early days of the COVID-19 pandemic (April 2nd to June 27th, 2020).Results: Sleep disturbance and depression prospectively predicted one another across eight weeks, and both directions were mediated by maladaptive emotion regulation. However, sleep and depression failed to predict change in one another controlling for baseline measures, directly or via emotion regulation.Conclusions: The results suggest that maladaptive emotion regulation is a potential mechanism through which sleep disturbance and depression help maintain high levels of one another in college students during the COVID-19 pandemic. Therefore, emotion regulation deficits are potentially an important target for interventions to interrupt the sleep disturbance-depression cycle.

Anxiety, Depression and Quality of Life-A Systematic Review of Evidence from Longitudinal Observational Studies

This review aimed to systematically review observational studies investigating the longitudinal association between anxiety, depression and quality of life (QoL). A systematic search of five electronic databases (PubMed, PsycINFO, PSYNDEX, NHS EED and EconLit) as well as forward/backward reference searches were conducted to identify observational studies on the longitudinal association between anxiety, depression and QoL. Studies were synthesized narratively. Additionally, a random-effects meta-analysis was performed using studies applying the mental and physical summary scores (MCS, PCS) of the Short Form Health Survey. The review was prospectively registered with PROSPERO and a study protocol was published. n = 47 studies on heterogeneous research questions were included, with sample sizes ranging from n = 28 to 43,093. Narrative synthesis indicated that QoL was reduced before disorder onset, dropped further during the disorder and improved with remission. Before onset and after remission, QoL was lower in comparison to healthy comparisons. n = 8 studies were included in random-effects meta-analyses. The pooled estimates of QoL at follow-up (FU) were of small to large effect sizes and showed that QoL at FU differed by disorder status at baseline as well as by disorder course over time. Disorder course groups differed in their MCS scores at baseline. Effect sizes were generally larger for MCS relative to PCS. The results highlight the relevance of preventive measures and treatment. Future research should consider individual QoL domains, individual anxiety/depressive disorders as well as the course of both over time to allow more differentiated statements in a meta-analysis.

Electromoxibustion for knee osteoarthritis in older adults: A pilot randomized controlled trial

BACKGROUND

Electromoxibustion devices are commercially available and can be self-administered by patients. Nevertheless, little is known about the effectiveness and potential burn injury of these devices as this topic is under-investigated.

OBJECTIVE

To assess the preliminary effects and safety of an electromoxibustion (EM) device for improving knee pain and joint functions in older adults with knee osteoarthritis (KOA).

DESIGN, SETTING, PARTICIPANTS AND INTERVENTION

This was a pilot two-armed assessor-blinded randomized controlled trial to assess the effects of electromoxibustion (EM) on older adults with KOA. A total of 38 subjects aged 60 or above, with KOA for 3 months or above were recruited. Participants were randomized to the EM group or the knee health education group. The intervention group (n = 21) received 12 sessions of EM spanning across four weeks, while the control group (n = 17) received two sessions of knee health education.

MAIN OUTCOME MEASURES

Primary outcome included the pain severity Numerical Rating Scale (NRS) at baseline and week 4. Secondary outcomes included the Western Ontario and McMaster University Osteoarthritis Index (WOMAC), Short-Form Six-Dimension (SF6D), Timed Up & Go Test (TUG) and Fast Speed Gait (FSG).

RESULTS

Both groups showed a decreasing trend in knee pain intensity by NRS at post-intervention. There were also trends of improvement in the WOMAC score, TUG score, FGS test score and SF-6D score at week 4. Only a small between-group effect size (d = 0.13) was found, but medium between-group effects sizes were found in the WOMAC total score (d = 0.40) and WOMAC functional sub-score (d = 0.51). However, the differences were not statistically significant.

CONCLUSION

This study suggested that EM may be beneficial for KOA in older adults, particularly in terms of improving knee function. Replication of similar studies in larger RCTs is warranted to confirm the effectiveness of EM on reducing pain and knee function of older adults with KOA.

TRAIL REGISTRATION NUMBER

NCT04034394.

Emotional problems and health-related quality of life: population-based study

PURPOSE

The aim of the present study was to evaluate the influence of emotional problems on health-related quality of life (HRQoL) according to the type of emotional problem, degree of limitation, and perceived control of the problem with treatment.

METHOD

A population-based cross-sectional study with probabilistic stratified cluster sampling was conducted in 2014 and 2015 in the city of Campinas, Brazil. A total of 2145 individuals aged 18 years or older participated in the study. HRQoL was evaluated using the SF-36^® questionnaire. The dependent variables were the score of the eight scales of the SF-36^®. The independent variables were self-perceived emotional problems, type of emotional problem (according to ICD 10), degree of limitation, and perceived control of the problem with treatment. Mean scores were calculated and regression coefficients were adjusted for sex, age, number of health problems, and chronic diseases using multiple linear regression analysis.

RESULTS

The prevalence of emotional problems was 32.7%. Among the individuals with a problem, the mean SF-36^® scores were lower on all domains. Regarding the type of emotional problem, a complaint of depression exerted a stronger negative impact on HRQoL scores than anxiety. Moreover, a greater degree of limitation caused by the problem led to lower mean SF-36^® scores. The negative impact on HRQoL was substantially greater among those who did not have the problem under control.

CONCLUSION

In conclusion, the findings underscore the importance of the prevention and control of emotional problems with the aim of reducing the impact on HRQoL.

What Interventions Improve Outcomes for the Patient Who Is Depressed and in Pain?

SPECIFIC CLINICAL ISSUE

The purpose of this clinical consultation is to offer nurses evidence-based strategies to provide holistic care to their patients with comorbid depression and pain. The combination of depression and pain is common and, if not managed effectively, has negative outcomes. Treatment-resistance is one negative outcome. The worst-case scenario for unrelieved depression and/or pain is suicide.

MAJOR PRACTICE RECOMMENDATIONS BASED ON BEST EVIDENCE

Antidepressants, particularly duloxetine, have had efficacy for pain and depression. Cognitive behavioral therapy, an evidence-based treatment for depression, has been found to decrease pain. Examples of additional interventions include exercise, relaxation techniques, mindfulness, and music. Providing holistic nursing care and working with other disciplines optimizes more effective management of these co-occurring conditions.

The role of pain in chronic pain patients’ perception of health-related quality of life: a cross-sectional SQRP study of 40,000 patients

Background and aims

Health-related quality of life (Hr-QoL) reflects the burden of a condition on an overarching level. Pain intensity, disability and other factors influence how patients with chronic pain perceive their condition, e.g. Hr-QoL. However, the relative importance of these factors is unclear and there is an ongoing debate as to what importance pain measures have in this group. We investigated the importance of current pain level and mood on aspects of Hr-QoL in patients with chronic pain and investigated whether such relationships are influenced by demographics.

Methods

Data was obtained from the Swedish Quality Registry for Pain Rehabilitation (SQRP), between 2008 and 2016 on patients ≥18 years old who suffered from chronic pain and were referred to participating specialist clinics. Dependent variables were general Hr-QoL [using two scales from European Quality of Life instrument: EQ5D Index and the European Quality of Life instrument health scale (EQ thermometer)] and specific Hr-QoL [from the Short Form Health Survey (SF36) the physical component summary (SF36-PCS) and the mental (psychological) component summary (SF36-MCS)]. Independent variables were sociodemographic variables, pain variables, psychological distress and pain attitudes. Principal component analysis (PCA) was used for multivariate correlation analyses of all investigated variables and Orthogonal Partial Least Square Regression (OPLS) for multivariate regressions on health aspects.

Results

There was 40,518 patients (72% women). Pain intensity and interference showed the strongest multivariate correlations with EQ5D Index, EQ thermometer and SF36-PCS. Psychological distress variables displayed the strongest multivariate correlations with SF36-MCS. Demographic properties did not significantly influence variations in the investigated Hr-QoL variables.

Conclusions

Pain, mood and pain attitudes were significantly correlated with Hr-QoL variables, but these variables cannot explain most of variations in Hr-QoL variables. The results pinpoint that broad assessments (including pain intensity aspects) are needed to capture the clinical presentation of patients with complex chronic pain conditions.

Body talk: Sex differences in the influence of alexithymia on physical complaints among psychiatric outpatients

This study investigated the relationship between alexithymia and physical complaints among psychiatric outpatients, and whether sex moderated this relationship. Participants (N = 185) completed measures of physical complaints (bodily symptom burden, pain severity, pain interference), alexithymia, current symptom (depression, anxiety) distress, and somatosensory amplification (i.e., a person's tendency to be bothered by physical sensations). Hierarchical regression analyses were conducted, controlling for the influence of current psychiatric symptom distress and somatosensory amplification. Findings revealed differential relationships between alexithymia and physical complaints (pain interference) for women and men, in addition to main effects for sex and alexithymia. The findings suggest that the negative influence of alexithymia on bodily-related problems may not be universal.

Past Pain Experience and Experimentally induced Pain Perception

Many intercurrent factors may be involved in the modulation of the pain message and its expression, such as the previous experience of pain built along the life. In this study, we aimed to determine whether susceptibility to experimentally induced pain is differentially influenced by the individual previous painful experience in subjects with schizophrenia (SC) major depression (MD), and controls (C).

METHODS

The SC (30), MD (32) and C (30) groups participated in experimental pain tests (application of pressure and induction of ischemia) after a semi-structured interview to make an inventory of the previous painful experiences, and the evaluation of anxiety either with autonomic (heart rate, blood pressure) or psychological (Hospital Anxiety Depression scale HAD) measures, and catastrophism.

RESULTS

The reported pain intensities, severities, duration, of the previous pain events, and the number of previous painful events were equivalent in the three groups, except for the number of painful events experimented before the last six months which was lower in the MD group. Experimental pain sensitivity was influenced by the diagnosis, the HAD scores or the number and intensities of previous lived painful events.

CONCLUSION

The lack of a past experience of pain was comparable for the different groups, suggesting that psychiatric disorders do not affect the experience of pain associated with daily life or past events. For each subject, the reported previous experience of pain influences the present feeling of pain.

Correlates of residual fatigue in patients with major depressive disorder: The role of psychotropic medication

OBJECTIVE

Fatigue is not only a core symptom of major depressive disorder (MDD), but also a common residual symptom. We determined the sociodemographic, clinical, and pharmacologic factors that were associated with fatigue in patients with remission or partial remission of MDD.

METHODS

Data was derived from a randomized controlled trial of acupuncture in 137 MDD patients with residual symptoms. Fatigue was measured by Multidimensional Fatigue Inventory (MFI-20). Self-report and clinician-rated scales were used to assess psychopathology. 17-item Hamilton Depression Rating Scale (HDRS17) score≤7 denoted MDD remission.

RESULTS

Participants' average HDRS17 score was 10.5; 29.2% were in remission. The average MFI-20 score was 71.8; 83.2% had severe fatigue, defined as MFI-20 score≥60. Fifty-two of 137 participants (38%) were using sedating psychotropic medications. Antidepressant dosage ranged from 1-90mg fluoxetine equivalent and sedatives/hypnotics from 1-60mg diazepam equivalent. There were significant correlations between MFI-20 score and HDRS17 depression and anxiety subscores, Hospital Anxiety and Depression Scale (HADS) depression and anxiety subscores, and Pain Catastrophizing Scale score, but insomnia and daytime sleepiness, sociodemographics, current medical conditions, and psychotropic medication use were not significant correlates. Upon multiple regression, HADS and HDRS17 depression scores independently predicted MFI-20 score. In remission and partial remission subgroups, HADS depression score was an independent predictor.

LIMITATION

Participants were recruited from specialty psychiatric units; hence the findings may not be applicable in non-specialized settings.

CONCLUSION

Fatigue was predicted by depression severity in remitted or partially remitted MDD. Psychotropic medication and higher dosage were not associated with greater fatigue.

The incremental burden of pain in patients with depression: results of a Japanese survey

BACKGROUND

Major depressive disorder (MDD) is a chronic mental illness which affects an estimated 3% of the Japanese population. Many patients with MDD report painful physical symptoms, and research outside of Japan suggests such patients may represent a subtype of depression which is more severe and difficult to treat. There is no evidence available about the characteristics or incremental burden of these patients in Japan. The objective of this study was to quantify the incremental burden of physical pain among individuals in Japan diagnosed with depression.

METHODS

Data for individuals age 18 and older who reported a physician diagnosis of depression were obtained from the Japan National Health and Wellness Survey (NHWS). Respondents who also reported physical pain were matched to respondents who did not report pain using propensity scores and compared using bivariate statistics. Measures included Patient Health Questionnaire (PHQ-9) for depression severity, Medical Outcomes Study 12-Item Short Form Survey Instrument (SF-12v2) for health-related quality of life, the Work Productivity and Activity Impairment (WPAI) for work and activity impairment, and 6-month report of health care use.

RESULTS

Individuals with depression who reported physical pain had higher PHQ-9 depression scores (14.3 vs. 11.1, p<0.001), lower health-related quality of life (Mental Component Summary score [MCS] 29.1 vs. 32.0, p<0.01; Physical Component Summary score [PCS] 43.0 vs. 47.2, p<0.001; health utility [SF-6D] 0.567 vs. 0.613, p<0.001), more presenteeism (46.3% vs. 36.8%, p<0.01), more overall work impairment (51.4% vs. 42.3%, p<0.01), more activity impairment (55.4% vs. 43.9%, p<0.001), and reported using more health care provider visits in the prior 6 months (17.7 vs. 12.8, p<0.01) as well as hospitalizations (1.7 vs. 0.8, p<0.05) relative to propensity-score matched controls without pain. Absenteeism (13.1% vs. 11.4%, p=0.51) and emergency room visits (0.31 vs. 0.35, p=0.76) were not significantly different between the two matched groups.

CONCLUSIONS

Individuals whose depression is accompanied by physical pain have a higher burden of illness than those whose depression does not include physical pain. Clinicians should take the presence of pain into account and consider treating both the physical and emotional symptoms of these patients.

Association between pain severity, depression severity, and use of health care services in Japan: results of a nationwide survey

BACKGROUND

Depression is often associated with painful physical symptoms. Previous research has seldom assessed the relationship between the severity of physical symptoms and the severity of mental and emotional symptoms of depression or other health outcomes, and no such studies have been conducted previously among individuals with depression in Japan. The aim of this study was to assess the relationship between the severity of physical pain and depression and other outcomes among individuals in Japan diagnosed with depression.

METHODS

Data for individuals aged 18 and older in Japan who reported being diagnosed with depression and also reported physical pain were obtained from the Japan National Health and Wellness Survey. These respondents were characterized on sociodemographics and health characteristics, and the relationship between ratings of severity on pain in the last week and health outcomes were assessed using bivariate correlations and generalized linear models. Measures included the Patient Health Questionnaire for depression severity, Medical Outcomes Study 12-Item Short Form Survey Instrument for health-related quality of life, the Work Productivity and Activity Impairment for work and activity impairment, and 6-month report of health care use.

RESULTS

More severe physical pain in the past week was correlated with more severe depression, worse health-related quality of life, lower health utility, greater impairment at work, and more health care provider visits. These relationships remained significant after incorporating sociodemographics and health characteristics in the statistical models.

CONCLUSION

Individuals whose depression is accompanied by more severe physical pain have a higher burden of illness than those whose depression includes less severe pain, suggesting that even partially ameliorating painful physical symptoms may significantly benefit patients with depression. Clinicians should take the presence and severity of physical pain into account and consider treating both the physical and emotional symptoms of these patients.

Risk Factors Associated with Adverse Events of Acupuncture: A Prospective Study

Objective

Mild adverse events (AEs) are common with acupuncture, but the risk factors remain unclear. A prospective study using a standardised AE assessment and acupuncture protocol was undertaken to address the question.

Methods

A 20-item AE report form investigated local and systemic AEs in 150 adults with insomnia randomised to receive traditional, minimal and non-invasive sham acupuncture. Sociodemographic, clinical and psychological variables at baseline and past history and perceived credibility of acupuncture were assessed.

Results

The incidence of any AEs per patient was 42.4% with traditional acupuncture, 40.7% with minimal acupuncture and 16.7% with non-invasive sham acupuncture. Traditional and minimal acupuncture were associated with a greater number of local AEs, while the presence of a chronic medical condition was predictive of fewer local and systemic AEs. Greater severity of insomnia, anxiety, depression, somatic symptoms and pain catastrophising thoughts were associated with lower risk, but most of the significant correlations disappeared after logistic regression. Divorce and widowhood were the only significant sociodemographic variables, while previous acupuncture treatment and perceived credibility of acupuncture were found to be unrelated. The risk of any AEs was higher in participants receiving traditional acupuncture (OR 4.26) and minimal acupuncture (OR 4.27) and in those without medical comorbidity (OR 3.39).

Conclusions

The prevalence of AEs was higher than usual, probably due to the low threshold in our definition of AEs and the systematic collection from the patients’ perspective. Baseline variables were largely unable to predict AEs associated with acupuncture. Further studies should explore the roles of practitioners, patients’ anxiety during treatment and patient–practitioner interactions.

Trial Registration Number

NCT01707706.

The impacts of migraine and anxiety disorders on painful physical symptoms among patients with major depressive disorder

Background

No study has simultaneously investigated the impacts of migraine and anxiety disorders on painful physical symptoms (PPS) among patients with major depressive disorder (MDD). The study aimed to investigate this issue.

Methods

This open-label study enrolled 155 outpatients with MDD, who were then treated with venlafaxine 75 mg per day for four weeks. Eighty-five participants with good compliance completed the treatment. Migraine was diagnosed according to the International Classification of Headache Disorders. MDD and anxiety disorders were diagnosed using the Structured Clinical Interview for DSM-IV-TR. The visual analog scale (VAS) was used to evaluate the severity of eight PPS. Multiple linear and logistic regressions were used to investigate the impacts of migraine and anxiety disorders on PPS.

Results

Compared with patients without migraine, patients with migraine had a greater severity of PPS at baseline and post-treatment. After controlling for demographic variables and depressive severity, migraine independently predicted the intensities of eight PPS at baseline and four PPS post-treatment. Moreover, migraine independently predicted poorer treatment responses of chest pain and full remission of pains in the head, chest, neck and/or shoulder. Anxiety disorders predicted less full remission of pains in the abdomen and limbs.

Conclusion

Migraine and anxiety disorders have negative impacts on PPS among patients with MDD. Integrating the treatment of migraine and anxiety disorders into the management of depression might help to improve PPS and the prognosis of MDD.

Depression symptoms and chronic pain in the community population in Beijing, China

We explore the association of depressive symptoms and chronic pain (arthritis, back or neck pain, headache, or other pain) in a community population of Beijing, China. Two thousand four hundred and sixty nine residents aged 16 years and older were investigated in 2010. Data were collected from face-to-face interviews using the Composite International Diagnostic Interview-3rd version. The presence of chronic pain condition and depressive symptoms were analyzed using univariate and multivariate analysis methods. We found a 12-month prevalence of MDD (Major depressive disorder) at 3.28%. Nearly half (41.01%) of respondents with depressive symptoms also had at least one chronic pain condition, and 64.20% of subjects with MDD (Major depressive disorder) experienced at least one chronic pain. After adjusting for selected demographic variables, it was found by multivariate logistic regression analysis that depressive symptom without MDD was significantly associated with back-or neck pain (Adjusted odds ratio (AOR)=1.97, 95% CI, 1.34-2.90), headache (AOR=3.17, 95% CI, 1.81-5.58), and other chronic pain (AOR=2.21, 95% CI, 1.07-4.49). MDD was significantly associated with arthritis (AOR=2.23) back or neck pain (AOR=4.17), headache (AOR=3.16), and other chronic pain (AOR=3.51). Multiple types of chronic pain are associated with depressive symptoms and MDD. Future studies are needed to infer causality.

Time course of improvement of different symptom clusters in patients with major depression and pain treated with duloxetine or placebo

OBJECTIVE

This post hoc analysis assessed improvements in a broad range of psychopathological dimensions and in interference of pain with functioning as well as the time course of these improvements in patients with major depressive disorder (MDD) and pain treated with duloxetine versus placebo.

RESEARCH DESIGN AND METHODS

Data were derived from an 8-week, double-blind, placebo-controlled study in adult outpatients with MDD and non-specific physical pain. Mean times between improvement in Brief Pain Inventory (BPI) pain severity and interference of pain with functioning, depression severity, and dimensions of the Symptom Checklist-90 Revised (SCL-90-R) subscales were evaluated by responder analysis.

RESULTS

For all SCL-90-R subscores, a higher percentage of duloxetine-treated patients reached responder status (50% improvement) as compared to placebo, of these anger/hostility and interpersonal sensitivity had the highest response rates. In the duloxetine-treated group, response for anger/hostility, phobic anxiety, psychoticism, and most items assessing interference of pain with functioning was reached earlier than response for pain severity. The times to response for Montgomery-Asberg Depression Rating Scale (MADRS) and for pain severity were similar. In the placebo-treated group, times to response for depression, anxiety, and MADRS were longer than response for pain severity.

CONCLUSIONS

Duloxetine, and to a lesser degree placebo, not only improved depressive symptomatology and pain severity but also a much broader range of psychopathological symptoms. Time courses of improvements were different for duloxetine and placebo, in that depression and interference of pain with functioning improved earlier than pain severity in duloxetine-treated patients but not in placebo-treated patients. These results suggest that time to response is a valuable means of characterizing treatment effects.

LIMITATIONS

Pain was only assessed as a symptom and no further clinical diagnosis for pain syndromes were performed. CLINICAL TRIAL REGISTRY ID: www.clinicaltrial.gov - NCT00191919.