Pain and depression: an integrative review of neurobiological and psychological factors

A Nationally Scaled Telebehavioral Health Program for Chronic Pain: Characteristics, Goals, and Psychological Outcomes

BACKGROUND

Millions of U.S. adults suffer from chronic pain with a high prevalence of comorbid mental health issues. Telehealth-delivered behavioral therapy for chronic pain has been evaluated in the research setting. The purpose of this study was 1) to describe a nationally scaled, standardized, telebehavioral therapy program for patients with chronic pain and behavioral comorbidities, and 2) evaluate characteristics, goals, and psychosocial outcomes among program participants.

MATERIALS AND METHODS

This was mixed-methods retrospective cohort analysis among consecutive program graduates (mean age 53y; 24% male). The 8-week program was delivered by a licensed therapist and a behavior coach through telephone/secure video and tailored to each participant's behavioral health needs and goals. Participant chief complaints, behavioral goals, and mood triggers were abstracted by deidentified clinical record review using structured qualitative research methods. Depression, anxiety, and stress symptom data were collected at baseline and program graduation using the validated Depression Anxiety Stress Scales 21.

RESULTS

Back pain (42%) and hip/leg/knee pain (28%) comprised the most common chief complaints. Pain management (44%) and weight loss (43%) were the most frequently cited goals. At baseline, approximately half of participants had elevated depression (59%), anxiety (54%), and/or stress (48%) scores. Triggers for depressed, anxious, or stressed mood included severe pain (47%), health concerns (46%), and interpersonal relationship challenges (45%). At graduation, significant improvement in median depression (-54%), anxiety (-50%), and stress (-33%) symptom scores was observed among those with non-normal baseline values (p < 0.001); degree of improvement did not vary by participant age or sex.

CONCLUSIONS

Participants in a nationally scaled telebehavioral health program for chronic pain experienced significant improvement in depression, anxiety, and stress symptoms and shared several complaints, goals, and mood triggers.

Rethinking chronic pain in a primary care setting

Chronic pain substantially impacts patient function and quality of life and is a burden to society at large in terms of increased health care utilization and loss of productivity. As a result, there is an increasing recognition of chronic pain as a public health crisis. However, there remains wide variability in clinical practices related to the prevention, assessment, and treatment of chronic pain. Certain fundamental aspects of chronic pain are often neglected including the contribution of the psychological, social, and contextual factors associated with chronic pain. Also commonly overlooked is the importance of understanding the likely neurobiological mechanism(s) of the presenting pain and how they can guide treatment selection. Finally, physicians may not recognize the value of using electronic medical records to systematically capture data on pain and its impact on mood, function, and sleep. Such data can be used to monitor onset and maintenance of treatments effects at the patient level and evaluate costs at the systems level. In this review we explain how these factors play a critical role in the development of a coordinated, evidence-based treatment approach tailored to meet specific needs of the patient. We also discuss some practical approaches and techniques that can be implemented by clinicians in order to enhance the assessment and management of individuals with chronic pain in primary care settings.

Genetic and Environmental Influences on Sleep, Pain, and Depression Symptoms in a Community Sample of Twins

OBJECTIVE

We used quantitative genetic methods to evaluate whether sleep quality, pain, and depression symptoms share a common genetic diathesis, to estimate the genetic and environmental sources of covariance among these symptoms, and to test for possible causal relationships.

METHODS

A community sample of 400 twins from the University of Washington Twin Registry completed standardized self-report questionnaires. We used biometric modeling to assess genetic and environmental contribution to the association between sleep quality measured by the Pittsburgh Sleep Quality Index, pain measured by the Brief Pain Inventory, and depression symptoms measured by the Brief Symptom Inventory. Trivariate Cholesky structural equation models were used to decompose correlations among the phenotypes.

RESULTS

Heritability was estimated at 37% (95% confidence interval = 20%-51%) for sleep quality, 25% (9%-41%) for pain, and 39% (22%-53%) for depression. Nonshared environmental influences accounted for the remaining variance. The genetic correlation between sleep quality and pain had an rg value of .69 (95% confidence interval [CI] = 0.33-0.97), rg value of .56 (95% CI = 0.55-0.98) between pain and depression, and rg value of .61 (95% CI = 0.44-0.88) between depression and sleep quality. Nonshared environmental overlap was present between pain and sleep quality as well as depression and sleep quality.

CONCLUSIONS

The link between sleep quality, pain, and depression was primarily explained by shared genetic influences. The genetic factors influencing sleep quality and pain were highly correlated even when accounting for depression. Findings support the hypothesis of a genetic link between depression and pain as well as potential causality for the association of sleep quality with pain and depression.

5-HT modulation of pain perception in humans

INTRODUCTION

Although there is clear evidence for the serotonergic regulation of descending control of pain in animals, little direct evidence exists in humans. The majority of our knowledge comes from the use of serotonin (5-HT)-modulating antidepressants as analgesics in the clinical management of chronic pain.

OBJECTIVES

Here, we have used an acute tryptophan depletion (ATD) to manipulate 5-HT function and examine its effects of ATD on heat pain threshold and tolerance, attentional manipulation of nociceptive processing and mood in human volunteers.

METHODS

Fifteen healthy participants received both ATD and balanced amino acid (BAL) drinks on two separate sessions in a double-blind cross-over design. Pain threshold and tolerance were determined 4 h post-drink via a heat thermode. Additional attention, distraction and temperature discrimination paradigms were completed using a laser-induced heat pain stimulus. Mood was assessed prior and throughout each session.

RESULTS

Our investigation reported that the ATD lowered plasma TRP levels by 65.05 ± 7.29% and significantly reduced pain threshold and tolerance in response to the heat thermode. There was a direct correlation between the reduction in total plasma TRP levels and reduction in thermode temperature. In contrast, ATD showed no effect on laser-induced pain nor significant impact of the distraction-induced analgesia on pain perception but did reduce performance of the painful temperature discrimination task. Importantly, all findings were independent of any effects of ATD on mood.

CONCLUSION

As far as we are aware, it is the first demonstration of 5-HT effects on pain perception which are not confounded by mood changes.

Gifts and influence: Conflict of interest policies and prescribing of psychotropic medications in the United States

The pharmaceutical industry spends roughly 15 billion dollars annually on detailing - providing gifts, information, samples, trips, honoraria and other inducements - to physicians in order to encourage them to prescribe their drugs. In response, several states in the United States adopted policies that restrict detailing. Some states banned gifts from pharmaceutical companies to doctors, other states simply required physicians to disclose the gifts they receive, while most states allowed unrestricted detailing. We exploit this geographic variation to examine the relationship between gift regulation and the diffusion of four newly marketed medications. Using a dataset that captures 189 million psychotropic prescriptions written between 2005 and 2009, we find that uptake of new costly medications was significantly lower in states with marketing regulation than in areas that allowed unrestricted pharmaceutical marketing. In states with gift bans, we observed reductions in market shares ranging from 39% to 83%. Policies banning or restricting gifts were associated with the largest reductions in uptake. Disclosure policies were associated with a significantly smaller reduction in prescribing than gift bans and gift restrictions. In states that ban gift-giving, peer influence substituted for pharmaceutical detailing when a relatively beneficial drug came to market and provided a less biased channel for physicians to learn about new medications. Our work suggests that policies banning or limiting gifts from pharmaceutical representatives to doctors are likely to be more effective than disclosure policies alone.

Describing the population health burden of depression: health-adjusted life expectancy by depression status in Canada

INTRODUCTION

Few studies have evaluated the impact of depression in terms of losses to both premature mortality and health-related quality of life (HRQOL) on the overall population. Health-adjusted life expectancy (HALE) is a summary measure of population health that combines both morbidity and mortality into a single summary statistic that describes the current health status of a population.

METHODS

We estimated HALE for the Canadian adult population according to depression status. National Population Health Survey (NPHS) participants 20 years and older (n = 12 373) were followed for mortality outcomes from 1994 to 2009, based on depression status. Depression was defined as having likely experienced a major depressive episode in the previous year as measured by the Composite International Diagnostic Interview Short Form. Life expectancy was estimated by building period abridged life tables by sex and depression status using the relative risks of mortality from the NPHS and mortality data from the Canadian Chronic Disease Surveillance System (2007-2009). The Canadian Community Health Survey (2009/10) provided estimates of depression prevalence and Health Utilities Index as a measure of HRQOL. Using the combined mortality, depression prevalence and HRQOL estimates, HALE was estimated for the adult population according to depression status and by sex.

RESULTS

For the population of women with a recent major depressive episode, HALE at 20 years of age was 42.0 years (95% CI: 40.2-43.8) compared to 57.0 years (95% CI: 56.8-57.2) for women without a recent major depressive episode. For the population of Canadian men, HALE at 20 was 39.0 years (95% CI: 36.5-41.5) for those with a recent major depressive episode compared to 53.8 years (95% CI: 53.6-54.0) for those without. For the 15.0-year difference in HALE between women with and without depression, 12.3 years can be attributed to the HRQOL gap and the remaining 2.7 years to the mortality gap. The 14.8 fewer years of HALE observed for men with depression equated to a 13.0-year HRQOL gap and a 1.8-year mortality gap.

CONCLUSION

The population of adult men and women with depression in Canada had substantially lower healthy life expectancy than those without depression. Much of this gap is explained by lower levels of HRQOL, but premature mortality also plays a role.

Pain severity, interference, and prescription analgesic use among depressed, low-income homebound older adults

OBJECTIVES

Disabled, homebound individuals tend to suffer both chronic pain and depression; however, low-income, homebound older adults have been underexposed in pain and depression research. We examined the extent of pain frequency, intensity, and interference; the relationship between pain and depressive symptoms; and prescription analgesic use and its association with use of antidepressant and anxiolytic medications among these older adults.

METHOD

The data came from the baseline assessment of 215 homebound individuals aged 50+ who were referred to a clinical trial of depression treatment. Bivariate and multivariate analyses were used to examine the research questions.

RESULTS

Almost 87% (n = 186) of the participants reported having had chronic pain in the preceding three months. Of the pain reporters, the mean frequency, intensity, and interference of pain were 8.65 ± 2.05, 7.71 ± 2.10, and 7.80 ± 2.82, respectively, on a 1-10 scale, and 61% were taking a prescription analgesic. Analgesic users and nonusers did not differ in depressive symptoms and in pain frequency and intensity, but analgesic users reported higher pain interference than nonusers (8.22 ± 2.46 vs. 7.14 ± 3.22; t = 2.44, df = 184, p = .016). Pain frequency and interference were significantly associated with depressive symptoms, and pain interference was significantly associated with analgesic use in multivariate analysis. Anxiolytic medication use was also correlated with analgesic use.

CONCLUSION

The findings underscore the significant pain-related problems in these vulnerable individuals and the need for recognizing and treating both pain and depression more effectively using both pharmacologic and nonpharmacologic interventions.

Growing up in a Bubble: Using Germ-Free Animals to Assess the Influence of the Gut Microbiota on Brain and Behavior

There is a growing recognition of the importance of the commensal intestinal microbiota in the development and later function of the central nervous system. Research using germ-free mice (mice raised without any exposure to microorganisms) has provided some of the most persuasive evidence for a role of these bacteria in gut-brain signalling. Key findings show that the microbiota is necessary for normal stress responsivity, anxiety-like behaviors, sociability, and cognition. Furthermore, the microbiota maintains central nervous system homeostasis by regulating immune function and blood brain barrier integrity. Studies have also found that the gut microbiota influences neurotransmitter, synaptic, and neurotrophic signalling systems and neurogenesis. The principle advantage of the germ-free mouse model is in proof-of-principle studies and that a complete microbiota or defined consortiums of bacteria can be introduced at various developmental time points. However, a germ-free upbringing can induce permanent neurodevelopmental deficits that may deem the model unsuitable for specific scientific queries that do not involve early-life microbial deficiency. As such, alternatives and complementary strategies to the germ-free model are warranted and include antibiotic treatment to create microbiota-deficient animals at distinct time points across the lifespan. Increasing our understanding of the impact of the gut microbiota on brain and behavior has the potential to inform novel management strategies for stress-related gastrointestinal and neuropsychiatric disorders.

The Subjective Experiences of Attention-Deficit/Hyperactivity Disorder of Chinese Families in Hong Kong: Co-Construction of Meanings in Multiple Family Groups

The subjective experiences of Chinese children in Hong Kong with attention-deficit/hyperactivity disorder (ADHD) are underexplored. This article reports the results of a qualitative study that aims to understand the subjective experiences of children with ADHD in Hong Kong, taken from among a clinical sample of Chinese families with children struggling with ADHD who have participated in cross-disciplinary research of multiple family groups (MFG). The participating children revealed the subjective experiences of their struggle with the disorder in response to their parents' concern at a "press conference," one of the MFG activities, which underscored the importance of developing a new social work model to meet the multiple psychosocial service needs of these families. The article concludes with the discussion of the implications for the new model.

Huntington's Disease: Prevalence and Psychological Indicators of Pain

Background

Huntington's disease (HD) is a genetic neurodegenerative condition that involves impairments in movement, cognition, and mood. Research is lacking in HD with regard to the prevalence of pain and the relationships between psychological factors and pain. The aim of this research was to investigate the prevalence of pain and identify the psychological factors associated with pain severity in people with HD.

Methods

This data-mining study used data from 1474 people who participated in the European Huntington's Disease Network (EHDN) REGISTRY study. Pain severity was measured using the Medical Outcome Study 36-item short-form health survey. Separate ordinal regression analyses were conducted with participant-rated and interviewer-rated psychological measures (the Hospital Anxiety and Depression Scale-Snaith Irritability Scale and the Unified Huntington's Disease Rating Scale). The psychological factors considered were anxiety, depression, irritability, aggression, low self-esteem, and apathy.

Results

The prevalence of pain in the total sample was 41% (stage I, 42%; stage II, 44%; stage III, 39%; stages IV and V, 50%). After controlling for confounding variables, pain severity was significantly associated with participant-rated anxiety and depression. Interviewer-rated anxiety, depression, and irritability also were significantly associated with severity of pain after controlling for confounding variables.

Conclusions

This research confirmed that pain is indeed an issue for people with HD, particularly during the later stages of the disease. Caregivers and health professionals should consider the possibility that people with HD might be experiencing pain, particularly if they are showing signs of anxiety, depression, or irritability.

Depressed Mood Differentially Mediates the Relationship between Pain Intensity and Pain Disability Depending on Pain Duration: A Moderated Mediation Analysis in Chronic Pain Patients

Research has shown that pain is associated with disability and that depressed mood mediates the relationship between pain and disability. The question of whether duration of pain moderates these effects was addressed in this cross-sectional study with 356 chronic pain patients. A simple mediation model replicated the notion that depressed mood explains a significant proportion of the relationship between pain and disability (in the study at hand: 12%). A moderated mediation model revealed that the indirect effect of pain on disability through depressed mood is moderated by pain duration: while depressed mood did not mediate the effect of pain on disability in chronic pain patients with shorter pain duration, depressed mood significantly mediated the effect pain exerts on disability in chronic pain patients with longer pain duration. Pain duration did not moderate the direct effect of pain on disability. Implications of these findings for the treatment of chronic pain might be that targeting depressed mood is especially relevant in chronic pain patients with longer pain duration to reduce the effect of pain on disability.

Depression and Somatization Are Associated With Increased Postprandial Symptoms in Patients With Irritable Bowel Syndrome

BACKGROUND & AIMS

Patients with irritable bowel syndrome (IBS) have increased postprandial symptom responses and more psychosocial morbidities than healthy individuals. However, the relationship between psychosocial status and postprandial symptom responses in patients with IBS is unclear. We investigated this relationship in a prospective study of patients with IBS.

METHODS

A total of 193 IBS patients, diagnosed according to Rome II (n = 126) or Rome III (n = 67) criteria, consumed a standard breakfast (540 kcal: 36% fat, 15% proteins, 49% carbohydrates, and 8.9 g fiber). They completed visual analogue scales assessing the severity of 5 gastrointestinal symptoms (abdominal pain, bloating, nausea, gas, and fullness) before breakfast and every 30 minutes, up to 240 minutes after eating. All patients completed validated self-report questionnaires for their current levels of anxiety and depression; patients diagnosed based on Rome II criteria also completed a somatization questionnaire. The relationship between these variables and the course of gastrointestinal symptom scores over time was analyzed using linear mixed models, controlling for comorbid functional dyspepsia.

RESULTS

We observed a main effect of anxiety levels on fullness and bloating (P < .04), and of depression levels on abdominal pain (P = .007), reflecting a general upward shift of the entire symptom curve. Depression-by-time interactions were seen for nausea and gas (P < .03). Somatization levels had a main effect on all 5 symptoms (P < .0001), independent of anxiety and depression. We observed somatization-by-time interaction effects for bloating (P = .005), and nausea (P = .02), and a nonsignificant trend was found for pain (P = .054), reflecting a steeper early postprandial increase in symptoms among subjects with higher levels of somatization.

CONCLUSIONS

Based on a prospective study of patients with IBS, psychosocial morbidities are associated with increased levels of gastrointestinal symptoms in general. Depression and somatization levels are associated specifically with increased postprandial symptoms.

Crude estimates of cannabis-attributable mortality and morbidity in Canada-implications for public health focused intervention priorities

BACKGROUND

Cannabis is the most commonly used drug in Canada; while its use is currently controlled by criminal prohibition, debates about potential control reforms are intensifying. There is substantive evidence about cannabis-related risks to health in various key outcome domains; however, little is known about the actual extent of these harms specifically in Canada.

METHODS

Based on epidemiological data (e.g. prevalence of relevant cannabis use rates and relevant risk behaviors; risk ratios; and annual numbers of morbidity/mortality cases in relevant domains), and applying the methodology of comparative risk assessment, we estimated attributable fractions for cannabis-related morbidity and mortality, specifically for: (i) motor-vehicle accidents (MVAs); (ii) use disorders; (iii) mental health (psychosis) and (iv) lung cancer.

RESULTS

MVAs and lung cancer are the only domains where cannabis-attributable mortality is estimated to occur. While cannabis use results in morbidity in all domains, MVAs and use disorders by far outweigh the other domains in the number of cases; the popularly debated mental health consequences (e.g., psychosis) translate into relatively small case numbers.

CONCLUSIONS

The present crude estimates should guide and help prioritize public health-oriented interventions for the cannabis-related health burden in the population in Canada; formal burden of disease calculations should be conducted.

Is duloxetine's effect on painful physical symptoms in depression an indirect result of improvement of depressive symptoms? Pooled analyses of three randomized controlled trials

In treating Major Depressive Disorder with associated painful physical symptoms (PPS), the effect of duloxetine on PPS has been shown to decompose into a direct effect on PPS and an indirect effect on PPS via depressive symptoms (DS) improvement. To evaluate the changes in relative contributions of the direct and indirect effects over time, we analyzed pooled data from 3 randomized double-blind studies comparing duloxetine 60 mg/d with placebo in patients with major depressive disorder and PPS. Changes from baseline in Montgomery-Åsberg Depression Rating Scale total and Brief Pain Inventory-Short Form average pain score were assessed over 8 weeks. Path analysis examined the (1) direct effect of treatment on PPS and/or indirect effect on PPS via DS improvement and (2) direct effect of treatment on DS and/or indirect effect on DS via PPS improvement. At week 1, the direct effect of duloxetine on PPS (75.3%) was greater than the indirect effect through DS improvement (24.7%) but became less (22.6%) than the indirect effect (77.4%) by week 8. Initially, the direct effect of duloxetine on PPS was markedly greater than its indirect effect, whereas later the indirect effect predominated. Conversely, at week 1, the direct effect of treatment on DS (46.4%) was less than the indirect effect (53.6%), and by week 8 it superseded (62.6%) the indirect effect (37.4%). Thus, duloxetine would relieve PPS directly in the initial phase and indirectly via improving DS in the later phase.

Correlates of depressive symptoms in individuals attending outpatient stroke clinics

Background and purpose Depressive symptoms are common post-stroke. We examined stroke deficits and lifestyle factors that are independent predictors for depressive symptomology. Methods A retrospective chart review was performed for patients' post-stroke who attended outpatient clinics at a hospital in Southwestern Ontario between 1 January 2014 and 30 September 2014. Demographic variables, stroke deficits, secondary stroke risk factors and disability study measures [Patient Health Questionnaire-9 (PHQ-9) and Montreal Cognitive Assessment (MoCA)] were analyzed. Results Of the 221 outpatients who attended the stroke clinics (53% male; mean age = 65.2 ± 14.9 years; mean time post-stroke 14.6 ± 20.1 months), 202 patients were used in the final analysis. About 36% of patients (mean = 5.17 ± 5.96) reported mild to severe depressive symptoms (PHQ-9 ≥ 5). Cognitive impairment (CI), smoking, pain and therapy enrollment (p < 0.01) were significantly associated with depressive symptoms. Patients reporting CI were 4 times more likely to score highly on the PHQ-9 than those who did not report CI (OR = 4.72). While controlling for age, MoCA scores negatively related to depressive symptoms with higher PHQ-9 scores associated with lower MoCA scores (r= -0.39, p < 0.005). Conclusions High levels of depressive symptoms are common in the chronic phase post-stroke and were partially related to cognition, pain, therapy enrollment and lifestyle factors. Implications for Rehabilitation Stroke patients who report cognitive deficits, pain, tobacco use or being enrolled in therapy may experience increased depressive symptoms. A holistic perspective of disease and lifestyle factors should be considered while assessing risk of depressive symptoms in stroke patients. Patients at risk for depressive symptoms should be monitored at subsequent outpatient visits.

The type and prevalence of the use of analgesics among inpatients in a geriatric psychiatry department

OBJECTIVES

The association between the presence of pain and mental disorder is well known. The extent of pain treatment in psychiatric patients is estimated to be high, but there is a lack of recent studies focusing on analgesic treatment in patients with mental disorders. The use of analgesics can be associated with side effects, and it is possible that analgesics are not the correct treatment for chronic pain among patients with mental disorders.

METHODS

Data were obtained among inpatients in a geriatric psychiatry department at Aarhus University Hospital, Risskov, Denmark, between 1 April 2013 and 1 October 2013. The study examines the extent of analgesic use by patients at admission with a follow up at discharge to note any change during hospitalization.

RESULTS

A total of 89 patients aged 68 years or older were included (56 women, 33 men). At admission, 51.7% used analgesics, and this number did not change significantly from admission to discharge. A statistically significant increased risk of analgesic use was found in females (odds ratio 4.0). The indications for analgesic use were not present in 34.5% of the pain-treated patients at admission. At discharge, this number had been reduced to 23.1%. Paracetamol was the drug most frequently used, followed by opioids.

CONCLUSIONS

The use of analgesics among aged psychiatric inpatients is high. An increased focus on this topic is recommended.

Depression and pain: testing of serial multiple mediators

PURPOSE

Despite the fact that pain is related to depression, few studies have been conducted to investigate the variables that mediate between the two conditions. In this study, the authors explored the following mediators: cognitive function, self-sacrificing interpersonal problems, and perception of stress, and the effects they had on pain symptoms among patients with depressive disorders.

PARTICIPANTS AND METHODS

An analysis was performed on the data of 346 participants with unipolar depressive disorders. The 17-item Hamilton Depression Rating Scale, Mini-Mental State Examination, the pain subscale of the health-related quality of life (SF-36), the self-sacrificing subscale of the Inventory of Interpersonal Problems, and the Perceived Stress Scale were used. Parallel multiple mediator and serial multiple mediator models were used. An alternative model regarding the effect of self-sacrificing on pain was also proposed.

RESULTS

Perceived stress, self-sacrificing interpersonal style, and cognitive function were found to significantly mediate the relationship between depression and pain, while controlling for demographic variables. The total effect of depression on pain was significant. This model, with an additional three mediators, accounted for 15% of the explained variance in pain compared to 9% without mediators. For the alternative model, after controlling for the mediators, a nonsignificant total direct effect level of self-sacrificing was found, suggesting that the effect of self-sacrificing on pain was based only on an indirect effect and that perceived stress was found to be the strongest mediator.

CONCLUSION

Serial mediation may help us to see how depression and pain are linked and what the fundamental mediators are in the chain. No significant, indirect effect of self-sacrificing on pain was observed, if perceived stress was not part of the depression and/or cognitive function mediational chain. The results shown here have implications for future research, both in terms of testing the model and in clinical application.

Synergistic effect between back pain and common mental disorders and the risk of future disability pension: a nationwide study from Sweden

BACKGROUND

The aim of this study was to analyse a possible synergistic effect between back pain and common mental disorders (CMDs) in relation to future disability pension (DP).

METHOD

All 4,823,069 individuals aged 16-64 years, living in Sweden in December 2004, not pensioned in 2005 and without ongoing sickness absence at the turn of 2004/2005 formed the cohort of this register-based study. Hazard ratios (HRs) and 95% confidence intervals (CIs) for DP (2006-2010) were estimated. Exposure variables were back pain (M54) (sickness absence or inpatient or specialized outpatient care in 2005) and CMD (F40-F48) [sickness absence or inpatient or specialized outpatient care or antidepressants (N06a) in 2005].

RESULTS

HRs for DP were 4.03 (95% CI 3.87-4.21) and 3.86 (95% CI 3.68-4.04) in women and men with back pain. HRs for DP in women and men with CMD were 4.98 (95% CI 4.88-5.08) and 6.05 (95% CI 5.90-6.21). In women and men with both conditions, HRs for DP were 15.62 (95% CI 14.40-16.94) and 19.84 (95% CI 17.94-21.94). In women, synergy index, relative excess risk due to interaction, and attributable proportion were 1.24 (95% CI 1.13-1.36), 0.18 (95% CI 0.11-0.25), and 2.08 (95% CI 1.09-3.06). The corresponding figures for men were 1.45 (95% CI 1.29-1.62), 0.29 (95% CI 0.22-0.36), and 4.21 (95% CI 2.71-5.70).

CONCLUSIONS

Co-morbidity of back pain and CMD is associated with a higher risk of DP than either individual condition, when added up, which has possible clinical implications to prevent further disability and exclusion from the labour market.

Chronic Pain in Irish Prison Officers: Profile and Predictors of Pain-Related Disability and Depression

OBJECTIVE

International research has consistently found increased risk for physical health and psychological difficulties among prison officers including elevated risk of assault resulting in acute pain. This study represented an exploratory examination of the experience of chronic pain conditions among Irish prison officers with particular reference to the psychosocial predictors of pain severity, pain interference, and depression.

DESIGN

A questionnaire battery was completed by 152 Irish prison officers. The questionnaires measured pain severity and interference, anxiety, depression, social support, coping strategies, and resilience.

RESULTS

Results showed that 48% of participants reported chronic pain based on the International Association for the Study of Pain definition. Psychological distress was high among respondents reporting chronic pain, with 38% of participants meeting the criteria for "probable depression" while 51% met the criteria for "probable anxiety disorder." In regression analyses, depression emerged as a significant predictor of both pain severity and pain interference while anxiety and pain interference emerged as significant predictors of depression.

CONCLUSION

Chronic pain appears to be prevalent in prison officers and is associated with both physical and psychological impairment. Health care staff in correctional facilities should be aware that these health difficulties are prevalent in the prison work environment.

Pain in older people with frailty

In this review we identified cohort and cross-sectional studies that assessed pain in community-dwelling older people (>65 years) reliably characterized as frail. Secondly, we considered biologically plausible mechanisms that may alter pain perception, or contribute to, or exacerbate pain in an older person with frailty. Thirdly, we considered specific implications of pain management for this group of people. From the limited data from the seven included studies, it would appear that the presence of pain is higher in older people with frailty compared with people characterized as pre-frail or not frail. Thus older people reporting pain are more likely to be frail. However, a lack of prospective data precludes inferences about the direction of the relationship: that is whether pain or frailty is the antecedent. Further research is needed to understand the direction of the relationship, and to identify appropriate pain management strategies for older people with frailty.

What Is the Relationship Between Depressive Symptoms and Pain During Functional Tasks in Persons Undergoing TKA? A 6-year Perioperative Cohort Study

BACKGROUND

Preoperative depressive symptoms have been shown in some but not all studies to be associated with poor self-reported pain and function outcomes. In addition, depressive symptoms after surgery have been shown to improve relative to preoperative levels.

QUESTIONS/PURPOSES

We hypothesized that (1) preoperative depressive symptoms would predict postoperative pain; (2) depressive symptoms would decrease after surgery; and (3) preoperative depressive symptoms would increase as the scheduled surgery date approached.

METHODS

Data from the Osteoarthritis Initiative, a National Institutes of Health-funded prospective multiyear cohort study, were used in this retrospective analysis. Persons from four communities were eligible if they had radiographic knee osteoarthritis or were at risk for developing knee osteoarthritis based on occupational, medical history, or body weight risk factors. A total of 4796 persons participated and rates of followup were 80% or greater over the course of the study. Participants completed a validated depressive symptom scale and the Knee Injury and Osteoarthritis Outcome Scale pain scale each year for 3 years before and 3 years after TKA. Latent growth curve modeling was used to model intercepts and slopes of pre- and postoperative depression and pain. Preoperative trajectories and intercepts were then used to predict postoperative pain and depressive symptoms adjusting for confounding variables.

RESULTS

After adjustment for potential confounding, we found no evidence that preoperative depressive symptoms predicted postoperative pain with function (estimate, 0.1; 95% confidence interval, -0.31 to 0.50; p = 0.64) or that depressive symptoms were reduced after surgery (z = 0.06, p = 0.80). We also found no evidence to indicate that preoperative depressive symptoms increased as the date of surgery approached (linear slope = 0.28, SE = 0.19, p = 0.15).

CONCLUSIONS

Preoperative and postoperative depressive symptoms in patients before and after TKA did not appreciably change over a 6-year perioperative period. Patient depressive symptoms were not reduced after surgery and did not appear to be related to less pain postoperatively. Our findings of no association between preoperative depressive symptom severity and postoperative pain and no reduction in postoperative depressive symptoms run counter to other available evidence, potentially attributable, in part, to a data collection process that occurred outside of orthopaedic surgeons' offices. Future research is needed to more fully explore the potential role of social desirability, the concept that patients respond in a way that they think the researcher or clinician wants them to respond in lieu of responding in a way that truly reflects the patient's status. Social desirability may influence a TKA patient's pain and function outcome assessment.

LEVEL OF EVIDENCE

Level I, prognostic study.

Anxiety and Depression in Bidirectional Relations Between Pain and Smoking: Implications for Smoking Cessation

Pain and tobacco smoking are highly prevalent and comorbid conditions that impose considerable burdens on individuals and health care systems. A recently proposed reciprocal model suggests that these conditions interact in a bidirectional manner, resulting in greater pain and the maintenance of tobacco addiction. Anxiety and depression are common among smokers in pain and have been identified as central mechanisms of interest. There is emerging evidence that smokers with anxiety/depression may experience more severe pain and functional impairment, greater pain-induced motivation to smoke, and increased sensitivity to pain during periods of smoking abstinence. Based on empirical findings, we hypothesize that these experiences may engender expectations that abstaining from smoking will exacerbate both pain and negative affect, thus eroding self-efficacy for smoking cessation and increasing perceived barriers to quitting. The goal of this narrative review is to examine the role of anxiety/depression in complex pain-smoking relations so as to advance evolving theoretical perspectives and inform the development of tailored interventions.

High Times for Painful Blues: The Endocannabinoid System in Pain-Depression Comorbidity

Depression and pain are two of the most debilitating disorders worldwide and have an estimated cooccurrence of up to 80%. Comorbidity of these disorders is more difficult to treat, associated with significant disability and impaired health-related quality of life than either condition alone, resulting in enormous social and economic cost. Several neural substrates have been identified as potential mediators in the association between depression and pain, including neuroanatomical reorganization, monoamine and neurotrophin depletion, dysregulation of the hypothalamo-pituitary-adrenal axis, and neuroinflammation. However, the past decade has seen mounting evidence supporting a role for the endogenous cannabinoid (endocannabinoid) system in affective and nociceptive processing, and thus, alterations in this system may play a key role in reciprocal interactions between depression and pain. This review will provide an overview of the preclinical evidence supporting an interaction between depression and pain and the evidence supporting a role for the endocannabinoid system in this interaction.

The impact of pain on systemic rheumatic diseases

Pain is associated with the different types of rheumatic syndromes because it is often the most troubling symptom of patients affected by any of these diseases. Some risk factors clearly play a major role in the clinical expression of pain and related syndromes, including genetics, age, gender, co-morbidities, traumas and psychological patterns, but there are no specific clinical, laboratory or neuroimaging markers that can indicate why and when a patient's localised pain will become chronic and widespread. Any type of pain must be treated not only appropriately, but also rapidly because the likelihood of developing some form of chronic pain is related to the duration of the peripheral pain stimulus. Chronic pain inevitably has a major impact on patients' quality of life because the loss of function undermines their ability to do everyday activities. Pain can be most effectively treated by carefully selecting various pharmacological and non-pharmacological interventions based on the characteristics of the pain itself, disease factors, psychological coping abilities, and lifestyle.

Effectiveness of Three Types of Interventions in Patients with Fibromyalgia in a Region of Southern Catalonia

Several pharmacological and nonpharmacological treatments can be used to alleviate the symptoms of fibromyalgia, although none of them are completely effective at present. In this study, we analyzed the effectiveness of different therapies in three groups of people diagnosed with fibromyalgia. The sample for this randomized controlled trial was made up of 66 people diagnosed with fibromyalgia in southern Catalonia. In turn, this sample was divided into three groups of 22 participants each, who were treated with: i) cervical infiltration with botulinum toxin, ii) group problem-solving therapy, or iii) both therapies. The variables recorded were quality of life, suicidal thoughts, perception of pain, quality of sleep, and satisfaction. Female patients composed 96.9% (n = 64) of the study sample. Satisfaction with the infiltration was 5.1 ± 2.7 points, while in group problem-solving therapy it was 6.6 ± 3.2. Self-perceived health in the infiltration group (p = .016) and the therapy group (p = .001) improved after the intervention took place. The risk of suicide decreased in the both treatments/groups (p = .049). Pain was reduced by 31.8% with infiltration, 13.6% with therapy, and 22.7% with both treatments. Anxiety/depression decreased by 45% with therapy, 36.3% with infiltration, and 36.3% with both treatments. The results also showed that the use of both treatments significantly reduces suicidal thoughts (p = .049). In conclusion, this study showed the complexity of reducing chronic pain and increasing the quality of life of people with fibromyalgia.

The risk of suicide mortality in chronic pain patients

Chronic pain has long been considered an important risk factor for suicidal behavior. Less well understood are the factors associated with the increased risk for suicide death within chronic pain populations. The purpose of this review is to examine recent research with regard to rates of and risk factors for suicide mortality in patients with chronic musculoskeletal pain. We conclude that patients with a number of chronic pain states are at increased risk for suicide death, and that this risk appears to be due, at least in part, to other well-known correlates of pain such as depression and substance use disorders. However, in all likelihood, there are aspects of chronic pain itself that add uniquely to an individual's suicide risk profile. Lastly, we address a theoretical perspective and offer recommendations for clinical practice.

Psychological aspects of chronic musculoskeletal pain

Chronic musculoskeletal pain, by its very nature, is associated with negative emotions and psychological distress. There are individual differences in personality, coping skills, behavioral adaptation, and social support that dramatically alter the psychological outcomes of patients with chronic pain. Patients who have an aspect of central pain amplification associated with mechanical or inflammatory pain and patients with fibromyalgia (FM) are likely to exhibit higher levels of psychological distress and illness behaviors. This manuscript discusses several different constructs for the association between chronic pain, central pain amplification, and psychological distress. The first key question addresses mechanisms shared in common between chronic pain and mood disorders, including the individual factors that influence psychological comorbidity, and the second addresses how pain affects mood and vice versa. Finally, the utility of cognitive behavioral approaches in the management of chronic pain symptoms is discussed.

Pain and depression: a neurobiological perspective of their relationship

Remarkable progresses have been achieved regarding the understanding of the neurobiological bases of pain and depression. The principal role of neurotransmitters, neuromodulators, and neurohormones has been proposed in the development of pain and depression. With the progression of molecular biology, an intricate interaction among biological factors accountable to the development and management of pain and depression has been also shown in a numerous preclinical and clinical researches. This mini-review will briefly describe the current issues and future research direction for better understanding of the relationship between pain and depression.

The associations between preexisting mental disorders and subsequent onset of chronic headaches: a worldwide epidemiologic perspective

Although there is a significant association between preexisting depression and later onset of chronic headache, the extent to which other preexisting mental disorders are associated with subsequent onset of headache in the general population is not known. Also unknown is the extent to which these associations vary by gender or by life course. We report global data from the WHO's World Mental Health surveys (n = 52,095), in which, by means of the Composite International Diagnostic Interview-3.0, 16 mental disorders from the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, were retrospectively assessed in terms of lifetime prevalence and age of onset. Frequent or severe headaches were assessed using self-reports. After adjustment for covariates, survival models showed a moderate but consistent association between preexisting mood (odds ratios [ORs] = 1.3-1.4), anxiety (ORs = 1.2-1.7), and impulse-control disorders (ORs = 1.7-1.9) and the subsequent onset of headache. We also found a dose-response relationship between the number of preexisting mental disorders and subsequent headache onset (OR ranging from 1.9 for 1 preexisting mental disorder to 3.4 for ≥5 preexisting mental disorders). Our findings suggest a consistent and pervasive relationship between a wide range of preexisting mental disorders and the subsequent onset of headaches. This highlights the importance of assessing a broad range of mental disorders, not just depression, as specific risk factors for the subsequent onset of frequent or severe headaches.

PERSPECTIVE

This study shows that there is a temporal association between a broad range of preexisting mental disorders and the subsequent onset of severe or frequent headaches in general population samples across the world.

Preclinical assessment of pain: improving models in discovery research

To date, animal models have not sufficiently "filtered" targets for new analgesics, increasing the failure rate and cost of drug development. Preclinical assessment of "pain" has historically relied on measures of evoked behavioral responses to sensory stimuli in animals. Such measures can often be observed in decerebrated animals and therefore may not sufficiently capture affective and motivational aspects of pain, potentially diminishing translation from preclinical studies to the clinical setting. Further, evidence indicates that there are important mechanistic differences between evoked behavioral responses of hypersensitivity and ongoing pain, limiting evaluation of mechanisms that could mediate aspects of clinically relevant pain. The mechanisms underlying ongoing pain in preclinical models are currently being explored and may serve to inform decisions towards the transition from drug discovery to drug development for a given target.

Persistent depressive symptoms and pain after cardiac surgery

OBJECTIVE

Our objectives were to describe trajectories of depressive symptoms and pain at hospital discharge and 6 weeks later and to examine the relationship of persistent depressive symptoms to pain.

METHODS

Before and 6 weeks after hospital discharge, 251 patients undergoing cardiac surgery (mean [SD] age = 67.3 [9.5] years; 73% male) completed the Beck Depression Inventory and the Brief Pain Inventory (BPI). Patients were categorized into two groups based on the presence or absence of persistent depressive symptoms (Beck Depression Inventory score >10 at both times). Between-group differences in pain interference (BPI-INT) and pain severity (BPI-SEV) were evaluated using repeated-measures analysis of variance. Linear regressions were performed to determine if changes in depressive symptoms were related to BPI-INT and BPI-SEV, controlling for demographic and clinical data.

RESULTS

Persistent (16.3%) or worsening depressive symptoms (15.3%) from hospital discharge to 6 weeks were observed; many experienced at least some persistent pain (BPI-INT 67.8%, BPI-SEV 47.8%). From discharge to 6 weeks, patients with persistent depressive symptoms sustained higher levels of BPI-INT (p < .001) and BPI-SEV (p < .003). In multivariate analysis, only changes in depressive symptoms, not clinical and demographic variables, were related to BPI-INT (p < .001) and BPI-SEV (p = .001).

CONCLUSIONS

Persistent depressive symptoms are independently associated with continued pain up to 6 weeks after hospital discharge. Successful treatment of ongoing pain should include screening for depressive symptoms and initiation of appropriate treatment.

TRIAL REGISTRATON

Clinicaltrials.gov Identifier: NCT00522717.