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

Role of soluble epoxide hydrolase in pain and depression comorbidity

The coexistence of chronic pain and depression in clinical practice places a substantial social burden and profoundly impacts in patients. Although a clear correlation exists, the underlying mechanism of comorbidity between chronic pain and depression remains elusive. Research conducted in recent decades has uncovered that soluble epoxide hydrolase, a pivotal enzyme in the metabolism of polyunsaturated fatty acids, plays a crucial role in inflammation. Interestingly, this enzyme is intricately linked to the development of both pain and depression. With this understanding, this review aims to summarize the roles of soluble epoxide hydrolase in pain, depression, and their comorbidity. Simultaneously, we will also explore the underlying mechanisms, providing guidance for future research and drug development.

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.

Pain, mood, and suicidal behavior among injured working adults in Chile

BACKGROUND

Chronic pain is comorbid with psychiatric disorders, but information on the association of chronic pain with depressive symptoms, generalized anxiety, and suicidal behavior among occupational cohorts is inadequate. We investigated these associations among employed Chilean adults.

METHODS

A total of 1946 working adults were interviewed during their outpatient visit. Pain was assessed using the Short Form McGill Pain questionnaire (SF-MPG) while depression and generalized anxiety were examined using the Patient Health Questionnaire-9 (PHQ-9) and Generalized Anxiety Disorder-7 (GAD-7), respectively. The Columbia-Suicide Severity Rating Scale was used to assess suicidal behavior and suicidal ideation. Multivariable logistic regression models were used to estimate adjusted odds ratios (aORs) and 95% confidence intervals (95%CI) for the association of chronic pain with mood disorders, as well as suicidal behavior.

RESULTS

High chronic pain (SF-MPG > 11) was reported by 46% of participants. Approximately two-fifths of the study participants (38.2%) had depression, 23.8% generalized anxiety, 13.4% suicidal ideation, and 2.4% suicidal behavior. Compared to those with low pain (SF-MPG ≤11), participants with high chronic pain (SF-MPG > 11) had increased odds of experiencing depression only (aOR = 2.87; 95% CI: 2.21-3.73), generalized anxiety only (aOR = 2.38; 95% CI: 1.42-3.99), and comorbid depression and generalized anxiety (aOR = 6.91; 95% CI: 5.20-9.19). The corresponding aOR (95%CI) for suicidal ideation and suicidal behavior were (aOR = 2.20; 95% CI: 1.58-3.07) and (aOR = 2.18 = 95% CI: 0.99-4.79), respectively.

CONCLUSIONS

Chronic pain is associated with increased odds of depression, generalized anxiety, and suicidal behavior. Mental health support and appropriate management of patients experiencing chronic pain are critical.

Exploring Factors Associated With Depressive Symptoms Among Patients With Chronic Pain: A Cross-Sectional Multicenter Study

ABSTRACT

This cross-sectional study examined the factors associated with depression among people with chronic pain (PwCP) attending specialized pain clinics in Muscat, Oman. Two-hundred eighty-seven participants were recruited for the study, and univariate analyses were used to investigate the difference between individuals who scored above/below the cutoff points for depressive symptoms. A multiple regression analysis was used to detect the independent predictors. Twenty-six percent of participants scored above the cutoff point. Further analysis indicated that unstable family relationships pre-existing depressive symptoms (odds ratio [OR], 2.86; p = 0.044), a family history of depression (OR, 4.75; p = 0.019), severe pain (OR, 4.21; p < 0.006), having fibromyalgia (OR, 28.29; p = 0.005), and lumbago/truck (OR, 2.41; p = 0.039) were independent predictors of depressive symptoms. This study indicates that one in four patients with chronic pain also presents with depressive symptoms. However, the role of culture needs to be taken into consideration when interpreting these findings and when building on these data.

The role of microglia in chronic pain and depression: innocent bystander or culprit?

Clinical evidence shows that chronic pain and depression often accompany each other, but the underlying pathogenesis of comorbid chronic pain and depression remains mostly undetermined. Biotechnology is gradually revealing the phenotype and function of microglia, with great progress regarding microglia's role in neurodegeneration, depression, chronic pain, and other conditions. This article summarizes the role of microglia in chronic pain, depression, and comorbidities, which is conducive to finding new targets to treat chronic pain and depression.

Prevalence of Major Depressive Disorder Among Adults in China: A Systematic Review and Meta-Analysis

Background: Prevalence estimates of major depressive disorder (MDD) among adults in China have varied widely between studies. In this systematic review and meta-analysis, the overall prevalence of MDD in the Chinese population was estimated from published epidemiological studies and potential moderators that account for variability in estimates were assessed. Methods: A systematic literature search was conducted in PubMed, EMBASE, Web of Science, PsycINFO, China National Knowledge Internet (CNKI), and WanFang databases to identify relevant studies. Data analyses were conducted using the Comprehensive Meta-Analysis Version 2.0. Results: Forty studies comprising 1,024,087 subjects were included. The pooled point, 12-month, and lifetime prevalence rates of MDD in China were 1.1% (95% CI: 0.9-1.4%), 1.6% (95% CI: 1.0-2.5%), and 1.8% (95% CI: 1.5-2.2%), respectively. Subgroup and meta-regression analyses revealed gender, marital status, survey year, being published in English language, use of the Diagnostic and Statistical Manual of Mental Disorders (DSM) diagnostic systems and age as significant moderators of MDD prevalence. Conclusion: The overall prevalence of MDD in the Chinese population appears to be lower than that of most countries, but the rates have been increasing over time and are elevated in particular demographic subgroups. Due to the negative consequences of MDD, effective preventive measures, early identification, and timely treatments are still important and should be offered to those in need.

The association between the socioeconomic status and body pain: A nationwide survey

Pain is a significant burden among different communities, but little is known regarding the epidemiology of pain, particularly with respect to socioeconomic status (SES).The aim of the study was to estimate the prevalence of body pain and to identify risk factors of pain in middle-aged and older Chinese.The data were extracted from the 2008 Chinese Suboptimal Health Study that consisted of 18,316 Chinese subjects aged 18 to 65 years. Information on SES including occupation and education levels and body pain were collected. A Likert scale was used to evaluate reported body pain. We used the multiple logistic regression model to examine the association between SES and body pain.Overall, 65.34% reported body pain (male: 60.93%; female: 69.73%). After adjustments based on sex, age, education, area of residence, marital status, smoking, drinking and health status, the results showed that students (odds ratio [OR] = 1.51; 95% confidence interval [CI]: 1.32-1.74) and professionals (OR = 1.22; 95% CI: 1.08-1.37) had significant high risk for body pain, compared with civil servants and farmers (OR = 0.64; 95% CI: 0.55-0.75) who significantly lower risk of body pain. The study demonstrates there is a significant negative association between education and reported body pain.The results indicated an association between SES and body pain within the Chinese community. Body pain varied among different Chinese occupation-related population and people with higher education level are less like to have body pain.

The comorbidity of mental and physical disorders with self-reported chronic back or neck pain: Results from the China Mental Health Survey

BACKGROUND

To investigate mental and physical health comorbidity with chronic back or neck pain in the Chinese population, and assess the level of disability associated with chronic back or neck pain.

METHODS

Data were derived from a large-scale and nationally representative community survey of adult respondents on mental health disorders in China (n = 28,140). Chronic back or neck pain, other chronic pain conditions and chronic physical conditions were assessed by self-report. Mental disorders were assessed by the Composite International Diagnostic Interview (CIDI). Role disability during the past 30 days was assessed with the World Health Organization Disability Assessment Schedule (WHO-DAS-II).

RESULTS

The 12-month prevalence of chronic back or neck pain was 10.8%. Most of respondents with chronic back or neck pain (71.2%) reported at least one other comorbid condition, including other chronic pain conditions (53.4%), chronic physical conditions (37.9%), and mental disorders (23.9%). It was found by logistic regression that mood disorders (OR = 3.7, 95%CI:2.8-4.8) showed stronger association with chronic back or neck pain than anxiety disorders and substance disorders. Most common chronic pains and physical conditions were significantly associated with chronic back or neck pain. Chronic back or neck pain was associated with role disability after controlling for demographics and for comorbidities. Physical and mental comorbidities explained 0.7% of the association between chronic back or neck pain and role disability.

CONCLUSIONS

Chronic back or neck pain and physical-mental comorbidity is very common in China and chronic back or neck pain may increase the likelihood of other physical and mental diseases. This presents a great challenge for both clinical treatment and public health education. We believe that further study needs to be conducted to improve the diagnostic and management skills for comorbidity conditions.

Prevalence of major depressive disorder in older adults in China: A systematic review and meta-analysis

BACKGROUND

The prevalence of major depressive disorder (MDD) in Chinese older adults in epidemiological surveys have been inconsistent. We thus conducted a systematic review and meta-analysis of the pooled prevalence of MDD in older adults in China.

METHODS

Two investigators independently conducted a systematic literature search in English (PubMed, EMBASE, PsycINFO and Cochrane Library) and Chinese (CNKI, Sinomed and Wan Fang) databases. Studies reporting the prevalence of MDD in older adults in China using diagnostic instruments were identified and analyzed using the Comprehensive Meta-Analysis program.

RESULTS

A total of 28 studies with 76,432 subjects were included. The mean age ranged from 62.1 to 74.1 years. The point prevalence of MDD in older adults was 2.7% (95% CI: 2.1%-3.4%), 12-month prevalence was 2.3% (95% CI: 0.6%-8.5%), and lifetime prevalence was 2.8% (95% CI: 1.8%-4.4%). Subgroup analyses revealed significant differences in the prevalence of MDD across regions.

CONCLUSION

The prevalence of MDD in older adults varied across different regions in China. Further epidemiological studies and service planning should take into account such differences.

Pain perception of older adults in nursing home and home care settings: evidence from China

Background

In the past decade, the number of long-term care (LTC) services for older adults in China has grown annually by an average of 10%. Older adults, their family members, and policymakers in China are concerned about patient outcomes in different care settings because older adults who have a similar functional status and LTC needs may choose either nursing home care or home care. The aim of this study was to compare pain perception in nursing home care and home care settings for physically dependent older adults in China.

Methods

Multi-stage sampling method was used to recruit respondents aged 65 and older from Yichang City, China, in 2015. The researchers employed a two-step analytical strategy—zero-inflated ordered probit regression followed by propensity score matching method—to model the effect of contrasting residence types on pain perception.

Results

Zero-inflated ordered probit regression analysis with participants unmatched (n = 484) showed that compared with older adults who received home care, those who received nursing home care did not have more severe pain (β = 0.088, SE = 0.196, p = 0.655). After propensity-score matching, the research found that older adults in the home care group perceived less pain compared with the nursing home group (β = 0.489, SE = 0.169, p = 0.004).

Conclusions

The older adults who received home care perceived significantly less pain than the nursing home residents. The pain of older adults may differ based on the type of LTC services and therapy intensity they received, and home care might lead to less pain and better comfort than nursing home care.

Loss of Microglia and Impaired Brain-Neurotrophic Factor Signaling Pathway in a Comorbid Model of Chronic Pain and Depression

Major depressive disorder (MDD) and chronic pain are two complex disorders that often coexist. The underlying basis for this comorbidity is unknown. In the current investigation, microglia and the brain-derived neurotrophic factor (BDNF)-cAMP response element-binding protein (CREB) pathway were investigated. A comorbidity model, with characteristics of both MDD and chronic pain, was developed by the administration of dextran sodium sulfate (DSS) and the induction of chronic unpredictable psychological stress (CUS). Mechanical threshold sensory testing and the visceromotor response (VMR) were employed to measure mechanical allodynia and visceral hypersensitivity, respectively. RT-qPCR and western blotting were used to assess mRNA and protein levels of ionized calcium-binding adaptor molecule 1 (Iba-1), nuclear factor-kappa B (NF-κB), nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor, alpha (IκBa), BDNF, and CREB. In comorbid animals, mechanical allodynia and visceral hypersensitivities were significant with increased mRNA and protein levels for NF-κB-p65 and IκBa. Furthermore, the comorbid animals had deceased mRNA and protein levels for Iba-1, BDNF, and CREB as well as a reduced number and density of microglia in the medial prefrontal cortex (mPFC). These results together suggest that DSS and CUS can induce the comorbidities of chronic pain and depression-like behavior. The pathology of this comorbidity involves loss of microglia within the mPFC with subsequent activation of NF-κB-p65 and down-regulation of BDNF/p-CREB signaling.

Validations and psychological properties of a simplified Chinese version of pain anxiety symptoms scale (SC-PASS)

The Pain Anxiety Symptoms Scale (PASS) has been developed to evaluate pain anxiety, which leads to avoidance of daily activities and normal movements. However, a simplified Chinese version of PASS is still not available. Physicians are not aware of which patients are prone to anxiety, and what the risk factors are.To cross-culturally adapt the PASS into a simplified Chinese version and test the reliability and validity. Factors affecting pain anxiety were also explored.The PASS was first translated into a simplified Chinese version according to a forward-backward method. Then, validations were tested including content validity, construct validity, and reliability. Content validity was analyzed by response trend. Construct validity was analyzed by confirmatory factor analysis (CFA), exploratory factor analysis, and priori hypotheses testing. Reliability was analyzed by internal consistency and test-retest reliability. Risk factors of catastrophizing were analyzed by performing multivariate liner regression.A total of 219 patients were included in the study. The scores of items were well distributed. Both CFA and exploratory factor analysis suggested a 2nd-order, 4-factor model, accounting for 65.42% of the total variance according to principle component analysis. SC-PASS obtained good reliability with a Cronbach α = 0.92 and ICC = 0.90. College education, long pain duration, and both married and divorced status were risk factors. Factors reduced pain-related anxiety were no medication assumption, female sex, widowed status, non-Han ethnicity, and having no religious belief.The SC-PASS was applicable in Chinese patients and it was suitable for the clinical uses in mainland China.

Validation of a Chinese version of the Chronic Pain Acceptance Questionnaire (CAPQ) and CPAQ-8 in chronic pain patients

Acceptance of chronic pain has increasingly become a significant issue in the field of pain management. Many researchers have suggested that patients with better acceptance of pain are more likely to have better functioning both in physical and psychological status. In many countries, the Chronic Pain Acceptance Questionnaire (CPAQ) and CPAQ-8 have been validated and utilized frequently to measure the pain acceptance of patients with chronic pain. However, the CPAQ and CPAQ-8 yet have not been introduced and validated in Mainland China.In this study, we aimed to translate the English version of the CPAQ into simplified Chinese, make proper cross-cultural adaptations, and validate the psychometric properties of the Chinese version of the CPAQ and the CPAQ-8.The English version of the CPAQ was first linguistically translated and cross-culturally adapted to formulate a Chinese version. Then, we recruited 224 patients from a pain clinic and every participant was asked to finish a series of questionnaires. Finally, statistical analysis was performed to test the psychometric properties of the CPAQ and the CPAQ-8.Both confirmatory factor analysis (CFA) and principal component analysis (PCA) confirmed a 2-factor structure for the CPAQ and the CPAQ-8. Nine out of 10 of the hypotheses were validated for construct validity. The overall intraclass correlation coefficient (ICC) value for the CPAQ and CPAQ-8 were 0.92 and 0.89, respectively. In addition, the Cronbach α values for both the CPAQ and the CPAQ-8 showed excellent test-retest reliability.In conclusion, the original CPAQ was successfully developed into the Chinese version of the CPAQ and CPAQ-8 with excellent validity and reliability. The scores of the CPAQ or CPAQ-8 might be a strong predictor for the physical and psychological function of chronic pain patients. In addition, to improve the satisfaction of surgery patients, we recommend measuring patients' pain acceptance using the CPAQ or CPAQ-8 before and after the surgery. For patients with lower acceptance, psychological interventions may be more effective than treatment that simply reduces symptoms. Finally, we suggest that the Chinese version of the CPAQ and CPAQ-8 are appropriate for use in clinical settings or fundamental research in Mainland China.

Prevalence and characteristics of chronic body pain in China: a national study

Background

Chinese citizens regularly experience some form of bodily pain, yet little is known regarding the epidemiology of pain.

Methods

We conducted a nationally representative sample cross sectional study to estimate the prevalence of pain and identify risk factors of pain among 19,665 community residents aged 18–65 years in China. The China Sub-optimal Health Survey (CSHS) data was used to estimate pain prevalence. Body pain was also estimated by self-reports from the sample population. A logistical regression model was applied to estimate the odds ratio and 95 % CIs of acute pain and chronic pain to explore the potential risk factors.

Results

Women had a higher prevalence of pain than men (39.92 vs. 32.17 % for chronic pain). The prevalence of pain increased with age (29.72 % for ages 18–25 vs. 42.23 % for ages 45–65). The most common complaints were head, neck/shoulder, and waist/back pain. Females (OR 1.57, 95 % CI 1.44–1.71) ages 25 or older (25–45: OR 1.19, 95 % CI 1.04–1.36; 45–65: OR 1.47, 95 % CI 1.26–1.73) were more likely to report having chronic pain. Subjects’ living areas, and their drinking status (OR 1.32, 95 % CI 1.13–1.53) or smoking status (OR 1.01, 95 % CI 0.91–1.11), were also factors that were significantly associated with increased reporting of chronic pain.

Conclusion

Women had a higher prevalence of chronic pain than men, although both sexes had a high prevalence for chronic pain. There were significant differences between the two sexes and the location of chronic pain in the body, most notably in the shoulders, stomach, abdomen, and waist.

The Prevalence of Neck and Shoulder Symptoms and Associations with Comorbidities and Disability: The Johnston County Osteoarthritis Project

OBJECTIVES

Neck and shoulder pain are common but underreported by older people, raising important questions of frequency, medical comorbidities, gender and racial disparities and functional impact associated with neck and shoulder symptoms in elders, which we examined in this analysis.

METHODS

We performed a cross-sectional analysis in the community-based Johnston County Osteoarthritis Project, a cohort that is representative of the U.S. population, utilizing data from 1672 participants with a mean age of 68 years; 69% were white and 68% were women. Trained staff obtained data on participant-reported: symptoms, comorbidities, depression, and functional status; and performance-based functional assessments. Regression models of neck and shoulder symptoms and functional measures were adjusted for age, sex, race, and body mass index, and additionally for other joint symptoms and comorbidities.

RESULTS

Symptoms of neck (8%), shoulder (13%) or both (13%) were reported by participants. Neck symptoms were most frequently reported by White women; shoulder symptoms were evenly distributed among race and gender subgroups. Neck and shoulder symptoms were associated with cancer, diabetes mellitus, depression, and lung, cardiovascular, and other musculoskeletal problems, as well as pain, aching or stiffness at other sites, and independently with self-reported and performance -based functional measures.

CONCLUSIONS

These findings suggest that primary health care providers should inquire about neck and shoulder symptoms and address potential underlying causes to improve functional status and decrease disability in older people.

The Association Between Social Resources and Depressive Symptoms Among Chinese Migrants and Non-Migrants Living in Guangzhou, China

Background: Depression is a commonly studied mental disorder affecting Chinese internal (i.e., rural-to-urban) migrants. Social resources effectively reduce depression for many communities experiencing adversities. This study evaluated social-level risk factors for depression between internal migrant and non-migrant Chinese living in mainland China. Method: We conducted a random population-level survey among migrants and local residents living in Guangzhou, China. Data were collected using face-to-face interviews. We used items from the Social Support Rating Scale to measure social resource dimensions, including social network size, emotional support, structural social capital, and one (self-developed) item that measured belonging (an element of social cohesion). The Patient Health Questionnaire-9 measured depression. Correlation and regression analyses of the partial sample ( n = 678) were conducted to estimate the association between social resources and depression for migrants ( n = 383) and non-migrants ( n = 295). Results: Stratified regression analysis demonstrated that for migrants, greater belonging was associated with less depression, while age and larger friendship social network size was related to less depression among non-migrants. Conclusion: Differences emerged in our sample with regard to the types of social resources that are protective against depression between migrants and non-migrants. Interventions that provide opportunities for migrants to better integrate and feel welcomed into their new communities may reduce their depression symptoms.

A Systematic Review of the Prevalence and Measurement of Chronic Pain in Asian Adults

There are limited epidemiologic studies on chronic pain in Asian populations. The aim of this review was to gather all epidemiologic studies of chronic pain in Asian countries and systematically describe the measurement and prevalence of chronic pain in Asian adults. A systematic review was performed using PubMed, MEDLINE, EMBASE, Psych INFO, Cochrane Database for Systematic Review, and CINAHL. Additional studies were identified manually by searching bibliographies. We identified 19 relevant articles for this review. Most articles used the definition of chronic pain set by the International Association for the Study of Pain. The majority of the articles used simple single-question methods to measure chronic pain. The prevalence of chronic pain among Asian adults ranges from 7.1% (Malaysia) to 61% (Cambodia and Northern Iraq), whereas among the Asian geriatric population, the prevalence is even higher and ranges from 42% to 90.8%. This review showed that there is great variation in the reported prevalence of chronic pain in Asian adults and the prevalence of chronic pain is high among the Asian geriatric population. To measure the distribution of chronic pain in adults, a uniform measurement strategy should be adopted.

Impact of painful physical symptoms on depression outcomes in elderly Asian patients

ABSTRACT Background: Painful physical symptoms (PPS) are prevalent among elderly patients with depression. We describe the impact of PPS on depression outcomes and quality of life (QOL) of elderly Asian patients with major depressive disorder (MDD). Methods: This post hoc analysis of data from a three-month prospective observational study of East Asian MDD in- or out-patients focused on elderly patients aged ≥60 years. Depression severity was evaluated using the Hamilton depression (HAMD-17) and clinical global impression of severity (CGI-S) scales, while QOL was measured using EuroQOL (EQ-5D and EQ-VAS) instruments. PPS were rated using the modified somatic symptom inventory (SSI). Results: At baseline, depression was moderate to severe and 49% of the 146 elderly patients were painful physical symptom positive (PPS+). Bivariate analysis showed significant correlations between PPS and depression severity and QOL at baseline. Linear regression models showed the baseline factor most significantly associated with depression severity at three months was baseline PPS status. PPS+ patients had a mean increase of 2.87 points in their HAMD-17 rating and 0.77 points in their CGI-S score. Response and remission were significantly lower in PPS+ patients; response was 60% and remission was 40% in PPS+ patients while 82% and 66% in painful physical symptom negative (PPS-) patients. QOL at endpoint was lower in PPS+ patients. Conclusions: PPS are common in elderly Asian patients with MDD and negatively influence depression outcomes and QOL. Patients with PPS had lower QOL at baseline, lower response and remission rates, higher severity of depression, and lower QOL after three months of treatment.

Chronic administration of amitriptyline differentially alters neuropathic pain-related behaviour in the presence and absence of a depressive-like phenotype

Chronic pain and depression share a complex, reciprocal relationship. Furthermore, in addition to treating depression, antidepressants such as amitriptyline are a first-line treatment for chronic pain conditions, indicating possible common neural substrates underlying both depression and pain. However, there is a paucity of studies examining the effect of antidepressant treatment on nociceptive and neuropathic pain responding in the presence of a depressive phenotype. The current study aimed to examine the effect of chronic amitriptyline administration on neuropathic pain-related behaviour and associated neuroinflammatory processes in the olfactory bulbectomised (OB) rat model of depression. Nociceptive responding to mechanical, innocuous cold or noxious heat stimuli in sham or OB rats was not altered by chronic amitriptyline administration. The induction of neuropathic pain following L5-L6 spinal nerve ligation (SNL) resulted in robust mechanical and cold allodynia and heat hyperalgesia in both sham and OB vehicle-treated animals. Chronic amitriptyline administration attenuated SNL-induced mechanical allodynia in both sham and OB rats at day 7 post-SNL, an effect which was enhanced and prolonged in OB rats. In comparison, chronic amitriptyline administration attenuated SNL-induced cold allodynia and heat hyperalgesia in sham, but not OB, rats. Evaluating the affective/motivational aspect of pain using the place escape avoidance paradigm revealed that OB-SNL rats exhibit reduced noxious avoidance behaviour when compared with sham counterparts, an effect not altered by chronic amitriptyline administration. Chronic amitriptyline administration prevented the increased expression of GFAP, IL-10 and CCL5, and enhanced the expression of TNFα, in the prefrontal cortex of OB-SNL rats. In conclusion, these data demonstrate that chronic amitriptyline differentially alters somatic nociceptive responding following peripheral nerve-injury, depending on stimulus modality and the presence or absence of a depressive-like phenotype, an effect which may involve modulation of neuroinflammatory processes.

Which somatic symptoms are associated with an unfavorable course in Asian patients with major depressive disorder?

OBJECTIVE

To investigate the impact of somatic symptoms on the severity and course of depression in Asian patients treated for an acute episode of major depressive disorder (MDD).

METHODS

Three-month prospective observational study of 917 patients with MDD in psychiatric care settings of which 909 had complete main baseline data. Depression severity was assessed using the physician-rated Clinical Global Impression of Severity (CGI-S) and 17-item Hamilton Depression Rating Scale (HAMD17), and somatic symptoms were assessed using the patient-rated 28-item Somatic Symptom Inventory (SSI). Cluster analysis using baseline SSI scores grouped patients into 3 clusters with no/few, moderate or severe somatic symptoms. Four factors of SSI (pain, autonomic symptoms, energy, and central nervous system) were defined and regression analyses identified which factors were associated with remission and response at 3 months follow-up.

RESULTS

Baseline depression severity (HAMD17 and CGI-S scores) was associated with more severe somatic symptoms. Remission rates differed between clusters of patients: 68.4%, 54.7% and 29.3% for no/few, moderate and severe somatic symptoms, respectively (p<0.0001). Corresponding response rates were 81.8%, 72.1% and 55.2% (p<0.0001). Pain symptoms were the somatic symptoms most associated with these clinical outcomes at 3 months.

LIMITATIONS

Only patients diagnosed with MDD in psychiatric care were assessed.

CONCLUSIONS

Somatic symptoms are frequent among Asian patients in psychiatric care for MDD and are associated with greater clinical severity and lower response and remission rates. Among somatic symptoms, pain symptoms have the greatest prognostic value and should be taken into account when treating patients with depression.

Epidemiology of major depressive disorder in mainland china: a systematic review

BACKGROUND

Major depressive disorder (MDD) is one of the important causes of disease burden in the general population. Given the experiencing rapid economic and social changes since the early 1990s and the internationally recognized diagnostic criteria and interview instruments across the surveys during 2001-2010 in china, the epidemiological studies on MDD got varied results. We performed this meta-analysis to investigate current, 12-month and lifetime prevalence rates of MDD in mainland China.

METHODS

PubMed, Embase, Chinese Biological Medical Literature database (CBM), Chinese National Knowledge Infrastructure database (CNKI), and the Chinese Wanfang and Chongqing VIP database were searched for associated studies. We estimated the overall prevalence of MDD using meta-analysis.

CONCLUSIONS

Seventeen eligible studies were included. Our study showed that the overall estimation of current, 12-month and lifetime prevalence of MDD was 1.6, 2.3, 3.3%, respectively. The current prevalence was 2.0 and 1.7% in rural and urban areas, respectively; between female and male, it was 2.1 and 1.3%, respectively. In addition, the current prevalence of MDD diagnosed with SCID (Structured Clinical Interview for DSM-IV) was 1.8% and that diagnosed with CIDI (Composite International Diagnostic Interview) was 1.1%. In conclusion, our study revealed a relatively high prevalence rate in the lifetime prevalence of MDD. For current prevalence, MDD diagnosed with SCID had a higher prevalence rate than with CIDI; males showed a lower rate than females, rural residents seemed to have a greater risk of MDD than urban residents.