Depression in people with pain: There is still work to do Commentary on 'Understanding the link between depression and pain'

Neuroligins facilitate the development of bone cancer pain via regulating synaptic transmission: an experimental study

BACKGROUND

The underlying mechanism of chronic pain involves the plasticity in synaptic receptors and neurotransmitters. This study aimed to investigate potential roles of Neuroligins (NLs) within the spinal dorsal horn of rats in a newly established Bone Cancer Pain (BCP) model. The objective was to explore the mechanism of neuroligin involved in the occurrence and development of bone cancer pain.

METHODS

Using our rat BCP model, we assessed pain hypersensitivity over time. Quantitative real-time polymerase chain reaction and Western blot analysis were performed to investigate NL expression, and NLs were overexpressed in the rat spinal cord using lentiviral vectors. Immunofluorescence staining and whole-cell patch-clamp recordings were deployed to investigate the role of NLs in the development of BCP.

RESULTS

We observed reduced expression levels of NL1 and NL2, but not of NL3, within the rat spinal cord, which were found to be associated with and essential for the development of BCP in our model. Accordingly, NL1 or NL2 overexpression in the spinal cord alleviated mechanical hypersensitivity of rats. Electrophysiological experiments indicated that NL1 and NL2 are involved in BCP via regulating γ-aminobutyric acid-ergic interneuronal synapses and the activity of glutamatergic interneuronal synapses, respectively.

CONCLUSIONS

Our observations unravel the role of NLs in cancer-related chronic pain and further suggest that inhibitory mechanisms are central features of BCP in the spinal dorsal horn. These results provide a new perspective and basis for subsequent studies elucidating the onset and progression of BCP.

Endometriosis diagnosis buffers reciprocal effects of emotional distress on pain experience

OBJECTIVES

Emotional profile is involved in the experience of chronic pain related to endometriosis. Following the Örebro Model of Behavioral Emotion Regulation of Pain, the aim of this study was to understand the processes involved in the psychological adaptation to pain experienced during menstruations in women either diagnosed or not diagnosed with endometriosis.

METHODS

The study was conducted on a sample of 545 women, either diagnosed with endometriosis or not, during their menstruations. Functional repercussions and intensity of pain, catastrophic thinking, difficulties in emotional regulation and emotional distress were assessed through an online questionnaire. Structural equation modeling (SEM) was carried out.

RESULTS

Women diagnosed with endometriosis experience more suffering than women who have not had such a diagnosis. The model we adapted from Örebro's model fits the data well. A differential effect is observed regarding the retroactive effect of depression on pain. Although emotional distress increases functional repercussions among women both with and without the diagnosis, growing pain intensity only occurs among those without.

CONCLUSIONS

A woman presenting pain during menstruation faces emotional regulation issues that make her more vulnerable to the development of emotional distress. Pain impacts emotional distress, but emotional distress does not impact pain among women for whom the origin of the pain was known (i.e., a diagnosis of endometriosis). Having a diagnosis allows women to externalize the origin of their pain, attributing it to the disease and not to their psychological state.

Optimizing Cognitive Function in Persons With Chronic Pain

OBJECTIVES

Cognitive functioning is commonly disrupted in people living with chronic pain, yet it is an aspect of pain that is often not routinely assessed in pain management settings, and there is a paucity of research on treatments or strategies to alleviate the problem. The purpose of this review is to outline recent research on cognitive deficits seen in chronic pain, to give an overview of the mechanisms involved, advocate cognitive functioning as an important target for treatment in pain populations, and discuss ways in which it may be assessed and potentially remediated.

METHODS

A narrative review.

RESULTS

There are several options for remediation, including compensatory, restorative, and neuromodulatory approaches to directly modify cognitive functioning, as well as physical, psychological, and medication optimization methods to target secondary factors (mood, sleep, and medications) that may interfere with cognition.

DISCUSSION

We highlight the potential to enhance cognitive functions and identify the major gaps in the research literature.

Sleep disturbance linked to suicidal ideation in postural orthostatic tachycardia syndrome

OBJECTIVE

We investigated the prevalence of suicidal ideation in relationship with symptoms of sleep disruption in people with postural orthostatic tachycardia syndrome (POTS).

METHODS

Online surveys (including the Pittsburgh Sleep Quality Index and the Suicide Behaviors Questionnaire - Revised) were completed by 705 POTS patients and 170 non-POTS controls.

RESULTS

Poor sleep quality was reported in 98.4% of POTS patients with a calculated subjective sleep efficiency of 65.4%. The POTS group's sleep efficiency was significantly lower (t[873]= -11.32; p<0.001) and sleep disturbances because of pain were significantly higher (t[873]=15.36; p<0.001) than controls. Chi-square testing showed a larger proportion of individuals at high-risk for suicide among POTS patients than controls (c2 [1, n=875]=55.6; p<0.001). Multiple linear regression analysis showed that sleep scores (β=0.23, p<0.001), age (β=-0.03, p<0.001), and illness with POTS (β=0.68, p=0.05) were significantly associated with suicide ideation scores (F[4, 870]=38.34, p<0.001). This model explained 15% of variance (R2=0.15) in suicidal ideation scores.

CONCLUSION

Patients with POTS may suffer from increased sleep disturbance and suicidal ideation compared with the general population. Treatment to improve sleep efficiency and sleep quality is an important step toward better quality of life for POTS patients.

The Brazilian version of STarT Back Screening Tool - translation, cross-cultural adaptation and reliability

Background:

Psychosocial factors are not routinely identified in physical therapy assessments, although they can influence the prognosis of patients with low back pain. The "STarT Back Screening Tool" (SBST) questionnaire aids in screening such patients for poor prognosis in the primary care setting and classifies them as high, medium, or low risk based on physical and psychosocial factors.

Objectives:

This study sought to translate and cross-culturally adapt the SBST to the Brazilian Portuguese language and test the reliability of the Brazilian version.

Method:

The first stage of the study consisted of the translation, synthesis, and back-translation of the original version of the STSB, including revision by the Translation Group, pretest of the translated version, and assessment by an expert panel. The pre-final Brazilian version was applied to 2 samples comprising 52 patients with low back pain; these patients were of both genders and older than 18 years of age. To assess the instrument's reliability, an additional sample comprising 50 patients was subjected to 2 interviews, and the results were assessed using the quadratic weighted kappa value. The instrument's internal consistency was assessed using Cronbach's alpha (n=105), and the standard error of measurement was also calculated (n=50).

Results:

Translation and back-translation attained consensus, and only item 6 required changes; the reformulated version was applied to an additional sample comprising 52 individuals who did not report any doubts related to this item. The reliability of the SBST-Brazil was 0.79 (95% confidence interval: 0.63-0.95), the internal consistency was 0.74 for the total score and 0.72 for the psychosocial subscale, and the standard error of measurement was 1.9%.

Conclusion:

The translated and cross-culturally adapted SBST-Brazil proved to be reliable for screening patients according to their risk of poor prognosis and the presence of psychosocial factors.

Suicide attempts in chronic pain patients. A register-based study

Background

There are several studies about the relationship between depression and chronic non-malignant pain. These studies have shown that up to 50% of chronic pain patients are suffering from depression.

It is, therefore, reasonable to expect that pain patients would also have an increased risk of suicidal behaviour. This problem is not well studied.

Since 1990 the Centre for Suicide Research, Odense, Denmark has registered all suicide attempts in patients residing in the Region of Funen, Denmark.

The Pain Clinic, Odense University Hospital receives patients with chronic pain from the entire Region of Southern Denmark.

Purpose

The purpose of the study has been:

To investigate, whether patients treated in the Pain Clinic during the period from 1 January 2004 to 31 December 2009 had an increased risk of suicide attempts compared with the background population.

Materials and methods

The Register for Suicide Attempts (RSA) is a product of the WHO research programme WHO/EURO Multicentre Study on Para suicide. The RSA is a longitudinal person-based register. It contains information about people who have been in contact with the health care system in the County of Funen as a result of a suicide attempt.

The Pain Clinic, Odense University Hospital receives patients with non-malignant chronic pain from the Region of Southern Denmark with 1,194,659 inhabitants. Data about age, sex, and time of treatment for patients treated in the Pain Clinic during the period were registered. Time and method of the suicide attempts were registered in the RSA. By registry linkages between the patient registers it was possible to calculate any excess risk of suicide attempts in chronic pain patients in the study period.

We used a cohort design and calculated incidence rates (IR) and incidence rate ratios (IRRs) for suicide attempts, based on data from RSA. Poisson Regression analyses were used for calculation of IR and IRR for suicide attempts.

Results

In the study period from 1 January 2004 to 31 December 2009 1871 patients residing in the Region of Funen in Denmark were referred to The Pain Clinic.

In the patient group 258 suicide attempts in 110 persons were registered. In all 6% of the patient group had attempted suicide.

An increased risk of suicide attempts was found in the pain population as the incidence rate ratio (IRR) was 3.76 95% CI (3.22; 4.40). No statistical significant differences between men and women were found.

Conclusion

In a chronic non-malignant pain population, referred to a pain clinic, the risk of suicide attempts was increased.

Implications

It is important to be aware of risk factors for suicidal behaviour, i.e. pain history, depression, anxiety, abuse problems, and social problems when caring for patients with chronic pain. More knowledge and training of the staff caring for chronic pain patients are needed to decrease the risk of suicidal behaviour.

The individual and societal burden of chronic pain in Europe: the case for strategic prioritisation and action to improve knowledge and availability of appropriate care

BACKGROUND

Chronic pain is common in Europe and elsewhere and its under treatment confers a substantial burden on individuals, employers, healthcare systems and society in general. Indeed, the personal and socioeconomic impact of chronic pain is as great as, or greater, than that of other established healthcare priorities. In light of review of recently published data confirming its clinical and socioeconomic impact, this paper argues that chronic pain should be ranked alongside other conditions of established priority in Europe. We outline strategies to help overcome barriers to effective pain care resulting in particular from deficiencies in education and access to interdisciplinary pain management services. We also address the confusion that exists between proper clinical and scientific uses of opioid medications and their potential for misuse and diversion, as reflected in international variations in the access to, and availability of, these agents.

DISCUSSION

As the economic costs are driven in part by the costs of lost productivity, absenteeism and early retirement, pain management should aim to fully rehabilitate patients, rather than merely to relieve pain. Accredited education of physicians and allied health professionals regarding state-of-the-art pain management is crucial. Some progress has been made in this area, but further provision and incentivization is required. We support a tiered approach to pain management, whereby patients with pain uncontrolled by non-specialists are able to consult a physician with a pain competency or a specialist in pain medicine, who in turn can recruit the services of other professionals on a case-by-case basis. A fully integrated interdisciplinary pain service should ideally be available to patients with refractory pain. Governments and healthcare systems should ensure that their policies on controlled medications are balanced, safeguarding public health without undue restrictions that compromise patient care, and that physician education programmes support these aims.

SUMMARY

Strategic prioritization and co-ordinated actions are required nationally and internationally to address the unacceptable and unnecessary burden of uncontrolled chronic pain that plagues European communities and economies. An appreciation of the 'return on investment' in pain management services will require policymakers to adopt a long-term, cross-budgetary approach.