The psychopharmacologic treatment of depression and anxiety in the context of chronic pain

Headache attributed to psychiatric disorders

The association between psychiatric illness and headache is widely recognized. "Headache attributed to psychiatric disorder" is a new category of secondary headache introduced in the 2004 revision of the International Classification of Headache Disorders (ICHD-II) (Headache Classification Subcommittee of the International Headache Society, 2004). It represents a new, but not conclusive, step toward a better systematization of the topic "headache and psychological factors." From the early 1990s the involvement of psychological factors in headache disorders has been clearly identified as "psychiatric comorbidity." The current conceptualization of the term implies an association, more than casual, but likely not causal, between an index disease or disorder and one or more coexisting physical or psychological pathologies. Additionally, clarifying the direction, meaning, and weight of comorbidities has pathophysiological, nosological, course, and treatment implications. However, the study of comorbidity may present a series of difficulties related to the current understanding of the etiology and pathophysiology of diseases at the center of our attention. Sometimes, as happens in the subject of headache, we proceed against a background where many issues need to be clarified. In this chapter, we analyze the past and current literature, tracing the line from "migraine personality" to "psychiatric comorbidity" to "headache attributed to psychiatric disorders." Questions related to etiology, pathophysiology, and treatment options are discussed for different headache subtypes.

Patient-centered perspective on treatment outcomes in chronic pain

OBJECTIVE

To define patient-determined success criteria for fibromyalgia and back pain treatment across four outcome domains: pain, fatigue, emotional distress, interference with daily activities.

DESIGN

Retrospective correlational clinical sample design.

SETTING

Tertiary care clinics at health science center.

PATIENTS

248 fibromyalgia patients and 52 back pain patients.

INTERVENTIONS

N/A.

OUTCOME MEASURES

Patient Centered Outcomes Questionnaire, measures of usual pain intensity and pain unpleasantness.

RESULTS

Overall, for treatment to be considered successful, fibromyalgia patients required pain levels of 3.30 (54% reduction), fatigue levels of 3.08 (60% reduction), distress levels of 2.49 (60% reduction), and interference levels of 2.67 (63% reduction). Comparatively, back pain patients required pain levels of 2.23 (58% reduction), fatigue levels of 2.29 (57% reduction), distress levels of 1.65 (67% reduction), and interference levels of 1.81 (68% reduction). Overall, both fibromyalgia and back pain patients did not expect to meet their criteria for success.

CONCLUSIONS

Results highlight the importance of assessing the patient's view of successful outcome. Both fibromyalgia and back pain patients appear to have stringent criteria for success that existing treatments are often unlikely to meet. Comparison across groups indicated fibromyalgia patients have higher usual levels of pain, fatigue, distress, and interference. Interestingly, fibromyalgia patients also require greater changes across domains in order to consider treatment successful, despite rating higher levels of pain, fatigue, distress, and interference as successful. Recognizing patients' success criteria and treatment expectations encourages discussion and development of individualized treatment goals, and wider implementation of individualized treatment for chronic-pain populations is encouraged.

Psychiatric disorders and headache familial recurrence: a study on 200 children and their parents

The main aim of the study was to examine the relationship between headache and familial recurrence of psychiatric disorders in parents and their children. Headache history and symptomatology have been collected in a clinical sample of 200 patients and their families, using a semi-structured interview (ICHD-II criteria). Psychiatric comorbidity was assessed by DSM-IV criteria. Chi squares and a loglinear analysis were computed in order to evaluate the main effects and interactions between the following factors: frequency and headache subtypes (migraine/not-migraine) in children, headache (migraine/not-migraine-absent/present) in parents, headache (absent/present) in grandparents, and psychiatric comorbidity (absent/present) have been analyzed: 94 mothers (47%) and 51 fathers (25.5%) had at least one psychiatric disorder, mainly mood and anxiety disorders. Considering the significant prevalence of Psi-co in children (P < 0.0001), we compared it with the presence of familiarity to headache: a significant interaction has been found (P < 0.05) showing that migraineurs with high familial recurrence of headache had a higher percentage (74.65%) of psychiatric disorders, than no-migraineurs (52.17%). Absence of headache familial loading seems to be related to psi-co only in no-migraine headache (87.5 vs. 45.5%). The occurrence of psychiatric disorders is high in children with headache, but a very different pattern seems to characterize migraine (familial co-transmission of migraine and Psi-Co?) if compared with non-migraine headache.

Health service utilization in patients with major depression and co-morbid pain

AIMS

Patients with depression often have co-morbid pain symptoms. However, rates of service utilization by psychiatric in-patients with co-morbid pain symptoms are unknown. The purpose of this study is to estimate whether patients with major depression and co-morbid pain access medical treatment for their pain as much as their counterparts with psychiatric diagnoses other than major depression.

METHODS

A total of 103 patients (62 female; 41 male) were assessed for a diagnosis of major depression applying a psychiatric clinical interview followed by a self-report pain questionnaire, which assessed physical pain in psychiatric patients.

RESULTS

Patients with major depression reported higher rates of pain symptoms in the past 6 and 12 months than their counterparts with a psychiatric diagnosis other than major depression. Analysis of variance showed that patients with depression were less likely to attend medical and specialist services for their pain symptoms than their counterparts. On the contrary, depressed patients with pain attended more frequently general in-patient services than non-depressed patients with pain.

CONCLUSIONS

Patients with depression suffer high rates of pain symptoms, but are at higher risk of not accessing appropriate services suggesting inadequate service utilization. The results have implications for screening and health care delivery for psychiatric patients with pain.

Anxiety-like behaviour is attenuated by gabapentin, morphine and diazepam in a rodent model of HIV anti-retroviral-associated neuropathic pain

Neuropathic pain is commonly associated with affective disorders such as anxiety and depression. We have previously characterised a rodent model of HIV, anti-retroviral-associated neuropathy in which rats develop hypersensitivity to a punctate mechanical stimulus and display anxiety-like behaviour in the open field paradigm. To assess the potential of this behavioural paradigm for the assessment of pain related co-morbidities in rodent models of pain, here we test the sensitivity of this anxiety-like behaviour to the analgesic agents gabapentin and morphine in comparison to the known anxiolytic drug diazepam. We found that gabapentin (30 mg/kg, i.p.) and morphine (2.5 mg/kg, i.p.), which reduce mechanical hypersensitivity in these rats, significantly reduces measures of thigmotaxis in the open field. The effect of gabapentin and morphine did not differ significantly from diazepam (1 mg/kg, i.p.). This study highlights the potential use of this rodent model and behavioural paradigm in the validation of the affective component of novel analgesic pharmacological targets and elucidation of underlying pathophysiological mechanisms.

Comorbid painful physical symptoms and anxiety: prevalence, work loss and help-seeking

BACKGROUND

There is evidence that painful physical symptoms (PPS) are increased in patients with anxiety disorder (AD). This survey reports the 12-month prevalence and sociodemographic characteristics of PPS in subjects with and without AD, taking into account somatic comorbidity. In addition, the impact of PPS on work loss days (WLDs) and help-seeking was examined.

METHODS

In a cross-sectional, population-based study, a representative random sample of non-institutionalised adults from Belgium, France, Germany, Italy, The Netherlands and Spain (N=21,425) was interviewed using the World Mental Health Composite Diagnostic Interview (CIDI 3.0 of the WHO). 8296 respondents provided data on the occurrence of PPS, from which 5489 respondents reported the number of work loss days.

RESULTS

PPS were reported by 28% of respondents without AD and by 45% in those with AD. Female gender, higher age and lower educational level were predictive of PPS. No additive effect of AD and PPS was found on the WLD score, neither did the presence or not of a comorbid somatic disorder change the findings. Finally, respondents with both AD and PPS had numerically higher rates of help-seeking for emotional reasons (20.8% vs. 15.0% for respondents with AD but not PPS) and delayed their help-seeking for a numerically shorter period of time (289 vs. 413 days, respectively).

LIMITATIONS

The most important limitation of this study was its reliance on self-reported data about somatic disorders.

CONCLUSION

Approximately 45% of persons with anxiety disorder also reported the presence of PPS. No additive effect of AD and PPS was found on the WLD score, and the presence of PPS in AD does not delay help-seeking for emotional problems.

Mechanical and cold hypersensitivity in nerve-injured C57BL/6J mice is not associated with fear-avoidance- and depression-related behaviour

BACKGROUND

Neuropathic pain is associated with significant co-morbidity, including anxiety and depression, which impact considerably on the overall patient experience. However, pain co-morbidity symptoms are rarely assessed in animal models of neuropathic pain. To improve the clinical validity of a widely used rodent model of traumatic peripheral neuropathy, we have investigated fear-avoidance- and depression-related behaviours in nerve-injured and sham-operated mice over a 4 week period.

METHODS

Male C57BL/6J mice were subjected to partial sciatic nerve ligation (PSNL) or sham surgery and were assessed on days 7, 14, and 28 after operation. Withdrawal thresholds to punctate mechanical and cooling stimuli were measured. Mice were tested on the novel open-field and elevated plus-maze tests for fear-avoidance behaviour, and on the tail suspension test for depression-related behaviour.

RESULTS

Hypersensitivity to punctate mechanical and cool stimuli was evident up to day 28 after PSNL. However, there was no change in fear-avoidance- or depression-related behaviours regardless of interval after-surgery.

CONCLUSION

These data demonstrate that pain behaviour in nerve-injured C57BL/6J mice was not associated with alterations in emotion-related behaviours.

Biopsychosocial pain medicine and mind-brain-body science

This article reviews how emotions, behavior, and psychiatric comorbidity influence the course and outcome of chronic pain disorders and addresses methods of identifying and managing these problems in clinical practice. Successful medical rehabilitation for patients with chronic pain requires (1) appreciating the effects of biopsychosocial factors in the onset, course, and outcomes of pain disorders; (2) understanding neurobiologic mechanisms linking mind, brain, and body in the functions of pain perception and modulation; and (3) being able to review critically and use selectively the plethora of new medications and interventional technologies that are proposed in the literature. Deficits in these skills now are recognized as hazardous to the public health so that medical school education and post residency training in pain medicine is now mandatory in some states.

A treatment algorithm for neuropathic pain

BACKGROUND

Neuropathic pain is a chronic pain syndrome caused by drug-, disease-, or injury-induced damage or destruction of sensory neurons within the dorsal root ganglia of the peripheral nervous system. Characteristic clinical symptoms include the feeling of pins and needles; burning, shooting, and/or stabbing pain with or without throbbing; and numbness. Neuronal hyperexcitability represents the hallmark cellular mechanism involved in the underlying pathophysiology of neuropathic pain. Although the primary goal is to alleviate pain, clinicians recognize that even the most appropriate treatment strategy may be, at best, only able to reduce pain to a more tolerable level.

OBJECTIVE

The purpose of this review is to propose a treatment algorithm for neuropathic pain that health care professionals can logically follow and adapt to the specific needs of each patient. The algorithm is intended to serve as a general guide to assist clinicians in optimizing available therapeutic options.

METHODS

A comprehensive review of the literature using the PubMed, MEDLINE, Cochrane, and Toxnet databases was conducted to design and develop a novel treatment algorithm for neuropathic pain that encompasses agents from several drug classes, including antidepressants, antiepileptic drugs, topical antineuralgic agents, narcotics, and analgesics, as well as various treatment options for refractory cases.

RESULTS

Any of the agents in the first-line drug classes (tricyclic antidepressants, antiepileptic drugs, topical antineuralgics, analgesics) may be used as a starting point in the treatment of neuropathic pain. If a patient does not respond to treatment with at least 3 different agents within a drug class, agents from a second drug class may be tried. When all first-line options have been exhausted, narcotic analgesics or refractory treatment options may provide some benefit. Patients who do not respond to monotherapy with any of the first- or second-line agents may respond to combination therapy or may be candidates for referral to a pain clinic. Because the techniques used at pain clinics tend to be invasive, referrals to these clinics should be reserved for patients who are truly refractory to all forms of pharmacotherapy.

CONCLUSIONS

Neuropathic pain continues to be one of the most difficult pain conditions to treat. With the proposed algorithm, clinicians will have a framework from which to design a pain treatment protocol appropriate for each patient. The algorithm will also help streamline referrals to specialized pain clinics, thereby reducing waiting list times for patients who are truly refractory to traditional pharmacotherapy.

Comorbidities in Chronic Neuropathic Pain

Neuropathic pain arises from a lesion or dysfunction within the nervous system; the specific mechanisms that elicit neuropathic pain symptoms are the subject of ongoing research. It is generally acknowledged that neuropathic pain is extremely difficult to treat, and a major factor impacting outcomes is the presence of comorbidities such as poor sleep, depressed mood, and anxiety. Patients who suffer from chronic pain experience difficulties in initiating and maintaining sleep. Sleep deprivation has been associated with a decreased pain threshold, muscle aches, and stiffness in normal volunteers. The interrelationship of these factors is complex: Many chronic pain patients are depressed and anxious; sleep deprivation can lead to anxiety; and depression can be both the cause and the result of sleep disturbances. Thus, physicians must evaluate all aspects of pain, sleep, and mood in chronic pain patients. Several instruments have been developed to aid physicians in gathering qualitative and quantitative information from chronic pain patients. This triad of chronic pain, sleep disturbances, and depression/anxiety must be fully addressed if the patient is to be restored to optimal functionality. A multidisciplinary team approach allows for treatment of the whole patient. Nonpharmacologic interventions include relaxation therapy, sleep restriction therapy, and cognitive therapy. Strategies for pharmacologic interventions should attempt to maximize outcomes by employing, where possible, agents that address both the pain and the comorbidities. In this way, functionality may be restored and the patient's quality of life improved.

Psychiatric comorbidity in chronic daily headache: pathophysiology, etiology, and diagnosis

Chronic daily headache is a challenge for clinical practitioners and researchers. Etiology, pathophysiology, diagnosis, treatment, and prognosis of chronic daily headache present many questions that need answers. A chance occurrence of psychiatric disorders (mostly anxiety and mood disorders) in patients with chronic daily headache should not be excluded. This results in the need to understand the involved mechanisms, which requires us to draw new insights into the etiology, diagnosis, treatment, and prognosis of chronic daily headache. Psychiatric comorbidity seems to be cross-related to each of these dimensions, although the meanings need to be drawn. Each domain is discussed, considering the status of knowledge and stressing the future lines of research.