Pain and psychiatry: a critical analysis and pharmacological review

Anti-nociceptive and anti-inflammatory activities of the essential oil isolated from Cupressus arizonica Greene fruits

Background

Cupressus arizonica Greene is a coniferous tree with great importance in fragrance and pharmaceutical industries. Essential oils from C. arizonica (EC) have shown potential antioxidant, and anti-microbial activities. This study aimed at investigating the anti-nociceptive and anti-inflammatory effects/mechanisms of EC.

Methods

The EC was evaluated for anti-nociceptive and anti-inflammatory activities on male Wistar rats using a formalin test and carrageenan-induced paw edema, respectively. Also, we pre-treated some of the animals with naloxone and flumazenil in the formalin test to find out the possible contributions of opioid and benzodiazepine receptors to EC anti-nociceptive effects. Finally, gas chromatography/mass spectrometry (GC/MS) analysis was used to identify the EC’s constituents.

Results

EC in intraperitoneal doses of 0.5 and 1 g/kg significantly decrease the nociceptive responses in both early and late phases of the formalin test. From a mechanistic point of view, flumazenil administration 20 minutes before the most effective dose of EC (1 g/kg) showed a meaningful reduction in the associated anti-nociceptive responses during the early and late phases of the formalin test. Naloxone also reduced the anti-nociceptive role of EC in the late phase. Furthermore, EC at the doses of 1, 0.5, and 0.25 g/kg significantly reduced paw edema from 0.5 hours after carrageenan injection to 4 hours. GC/MS analysis showed that isolated EC is a monoterpene-rich oil with the major presence of α-pinene (71.92%), myrcene (6.37%), δ-3-carene (4.68%), β-pinene (3.71%), and limonene (3.34%).

Conclusions

EC showed potent anti-nociceptive and anti-inflammatory activities with the relative involvement of opioid and benzodiazepine receptors.

Depressive symptoms and health-related quality of life in a heterogeneous psychiatric sample: conditional indirect effects of pain severity and interference

BACKGROUND

Few studies have examined clinically relevant mechanisms that underlie the association between two important indices of recovery- depression severity and health-related quality of life (HRQOL) in psychiatric outpatients. This study aimed to explicate the roles of pain interference and pain severity as mediating and moderating mechanisms in the relationship between depressive symptoms and HRQOL.

METHODS

Data from 290 outpatients diagnosed with schizophrenia (n = 102), depressive (n = 98), and anxiety (n = 90) disorders were examined. Participants completed a set of questionnaires that queried their sociodemographic statuses, current pain severity and interference levels, depression severity levels, and HRQOL. Subsequently, mediation and moderation analyses were conducted.

RESULTS

Analyses revealed that pain interference fully mediated the relationship between depressive symptoms and physical (34% of the total effect) but not mental HRQOL. At high pain levels (+ 1 SD from mean), depressive symptoms may interfere with physical quality of life through pain interference, but this was not present at low pain levels (- 1 SD from mean).

CONCLUSIONS

Prolonged pain symptoms could negatively influence psychiatric recovery beyond the physical aspect of HRQOL. These results thus imply a need to detect and manage severe physical pain complaints at the acute stage in psychiatric outpatients.

Factors Associated With Opiate Use Among Psychiatric Inpatients: A Population-Based Study of Hospital Admissions in Ontario, Canada

Background:

Use of opiates, including synthetic opioids, is associated with a number of negative consequences, including increased risk of opioid use disorders and other mental health conditions. However, studies are limited in examining patterns of opiate use among persons in inpatient psychiatry, particularly those that consider the relationship between pain and opiate use.

Objective:

This study examined the prevalence in the prior 12 months to admission and patterns of opiate use and pain in a population-based study of persons admitted to inpatient psychiatry in Ontario, Canada.

Methods:

We conducted retrospective cross-sectional study of 165 434 persons admitted to inpatient psychiatry between January 1, 2006 and December 31, 2017. Using data from the Resident Assessment Instrument for Mental Health, we examined prevalence and factors associated with opiate use in the prior 12 months by a number of patient characteristics, including demographics, mental and physical health status, concurrent substance use, pain severity and frequency, and health region of residence.

Results:

The prevalence of opiate use within 12 months of admission was 7.5%, between 17% and 22% among those experiencing daily pain, and 27% among persons with a primary substance use disorder. Multivariable analyses revealed strong associations among demographic and clinical variables with opiate use (c = 0.91), including being of younger age, use of other substances, greater frequency and severity of pain, and health region of residence.

Conclusion:

The strong relationship between pain and opiate use in this population, and the regional variation in this pattern, supports the need for integrated care for mental illness and substance use, and therapeutic approaches to pain management that reduce risks of problems associated with substance use for persons with mental health conditions.

Pharmacogenetic Testing in Acute and Chronic Pain: A Preliminary Study

Background and Objectives: Pain is one of the most common symptoms that weighs on life’s quality and health expenditure. In a reality where increasingly personalized therapies are needed, the early use of genetic tests that highlights the individual response to analgesic drugs could be a valuable help in clinical practice. The aim of this preliminary study is to observe if the therapy set to 5 patients suffering of chronic or acute pain is concordant to the Pharmacogenetic test (PGT) results. Materials and Methods: This preliminary study compares the genetic results of pharmacological effectiveness and tolerability analyzed by the genetic test Neurofarmagen Analgesia^®, with the results obtained in clinical practice of 5 patients suffering from acute and chronic pain. Results: Regarding the genetic results of the 5 samples analyzed, 2 reports were found to be completely comparable with the evidences of the clinical practice, while in 3 reports the profile of tolerability and effectiveness were partially discordant. Conclusion: In light of the data not completely overlapping with results observed in clinical practice, further studies would be appropriate in order to acquire more information on the use of Neurofarmagen in routine clinical settings.

Determinants of suboptimal medication adherence in patients with a major depressive episode

BACKGROUND

Major Depression (MD) is often a chronic condition requiring a long-term pharmacologic treatment. Despite the efficacy of antidepressants, the medication adherence in those affected is usually very poor. In this scenario, further research concerning drivers of suboptimal adherence is needed. We aimed to explore medication adherence in patients with a MD episode, and to identify sociodemographic, clinical (psychiatric antecedents, comorbidities, medication, pain, and medication side effects), and psychosocial factors (negative life events, childhood trauma, and attitudes to medication) related to adherence status.

METHOD

The Medication Adherence Rating Scale (MARS) was completed by 370 patients at hospital admission. Participants were divided into groups of optimal and suboptimal adherence based on the medication adherence behavior score (MARS's factor 1), and were compared with respect to the study variables.

RESULTS

Twenty-nine percent of participants (n = 107) were found to be optimally adherents to their medication (score = 4/4). Compared to optimally adherents, suboptimally adherents (71%) presented a significantly higher depression severity, more psychiatric hospitalizations, suicidal ideation, physical pain, negative medication side effects, and antecedents of emotional maltreatment. Suboptimally adherents also had less favorable attitudes toward medication and were less in a relationship than optimally adherents. Multivariate analyses showed that depression severity, suicidal ideation, and physical pain increase the probability of belonging to the suboptimal adherent group.

CONCLUSION

These results suggest a vicious circle in which more vulnerable patients are less adherent to medication, which could worsen the clinical picture maintaining, in turn, low adherence. More efforts are needed to develop interventions aiming to improve medication adherence in MD patients.

Prevalence of central and peripheral neuropathic pain in patients attending pain clinics in Spain: factors related to intensity of pain and quality of life

Background

The objective of the study was to estimate the prevalence of pure central neuropathic pain (CNP) and peripheral neuropathic pain (PNP) among patients attending pain clinics in Spain. The study also aimed to analyze factors associated with pain intensity and quality of life (QoL).

Methods

A cross-sectional study was performed including 53 patients with pure CNP and 281 with pure PNP attending in 104 pain clinics in Spain. The revised grading system proposed in 2008 to determine a definite, probable or possible diagnosis of NP was used. Pain features, psychological variables and QoL were assessed. Descriptive, bivariate and multivariate analyses were performed.

Results

The prevalence of pure CNP and PNP amongst neuropathic pain patients was 2.4% (95% CI: 1.7;3.1) and 12.9% (95% CI: 1.5;14.3), respectively. Comorbid anxiety, depression or sleep disorders were high in both groups, but higher in CNP patients (51.1%, 71.4%, respectively). Pain intensity in PNP patients was associated with the presence of depression and sleep disturbances. However, in CNP patients, it was related with pain in the lower limbs. The impairment of QoL was greater in CNP patients than in PNP patients; pain location, presence of depression and sleep disturbance were the factors that most negatively affected QoL. Among PNP patients, women and those with higher pain intensity had worse QoL.

Conclusion

Pain intensity and QoL are affected by different factors in patients suffering from CNP or PNP. Identifying these factors could serve to guide therapeutic strategies and improve the QoL of patients.

Temporomandibular disorders in patients with schizophrenia using antipsychotic agents: a discussion paper

Patients with psychiatric problems show a tendency to develop temporomandibular disorders (TMD). Particularly, patients with schizophrenia are quite likely to have signs and symptoms of TMD due to the impairment of their oral health, the use of antipsychotic drugs, and other general health problems. In nonschizophrenic populations, TMD have been considered as the main cause of nondental pain in the orofacial region, involving mechanisms associated with changes in masticatory activity at the cortical and neuromuscular levels. Individuals with schizophrenia do not usually complain of pain, and TMD is misdiagnosed in this population. In this paper, we aimed to review the clinical aspects of TMD in people with schizophrenia on antipsychotic drug therapy.

Japanese clinical guidelines for chronic pain in children and adolescents

Chronic pain is a common problem in pediatric practice. The prevalence of chronic pain in children is >30%. Because pain indicates emotional expression as well as the physiological reaction toward infection, injury, and inflammation, both physiological and psychological assessments are essential to determine primary interventions for chronic pain. The Japanese Society of Psychosomatic Pediatrics Task Force of clinical practice guidelines for chronic pain in children and adolescents compiled clinical evidence and opinions of specialists associated with the primary care of pediatric chronic pain in the Japanese 'clinical guidelines for chronic pain in children and adolescents' in 2009, which are presented herein. The guidelines consist of three domains: general introduction to chronic pain; chronic abdominal pain; and chronic headache. Each section contains information on the physiological mechanism, psychological aspects, assessment methods, and primary interventions for pediatric chronic pain. These guidelines are expected to help disseminate knowledge on primary interventions for chronic pain in children and adolescents.

Current and emerging "at-site" pain medications: a review

The myriad pain pathophysiology has intrigued and challenged humanity for centuries. In this regard, the traditional pain therapies such as opioids and nonsteroidal anti-inflammatory drugs have been highly successful in treating acute and chronic pain. However, their drawback includes adverse events such as psychotropic effects, addiction potential, and gastrointestinal toxicities, to mention a few. These factors combined with the likelihood of an increase in chronic pain conditions due to an aging population calls for the development of novel mechanism-based or "site-specific" agents to target novel pain pathways. In this regard, rapid progress has been made in understanding the molecular mechanisms of novel pain targets such as cannabinoid receptors, fatty acid hydrolase, voltage-gated and ligand-gated ion channels such as P2 receptors, transient receptor potential channels and glial cell modulators. Accordingly, preclinical studies indicate that the site-specific/selective agents exhibit sufficient efficacy and reduced side effects such as lack of psychotropic effects indicating their clinical potential. This review provides a brief summary of some "at-site" pain targets and their role in the pain pathophysiology, and describes the efforts in developing some small molecules as novel pain therapeutics.

Prevalence of anxiety and depression in osteoarthritis: use of the Hospital Anxiety and Depression Scale as a screening tool

The aims of this study are to ascertain the prevalence of anxiety and depressive disorders in an outpatient population with osteoarthritis (OA), examine the interrelationships between severity of OA, pain, disability, and depression, and evaluate the Hospital Anxiety and Depression Scale (HADS) as a screening tool for this population. Patients with lower limb OA were evaluated with the Short Form McGill Pain and Present Pain Index Questionnaires, and a visual analogue scale, WOMAC Osteoarthritis Index-section C, and the HADS. Participants underwent a structured clinical interview by a liaison psychiatrist (AB). X-rays of affected joints were rated for disease severity. Fifty-four patients (42 females; mean age 63.3) were investigated. The prevalence of clinically significant anxiety and/or depression was 40.7% (95% confidence interval (CI), 27.6-55.0%). HADS was a good predictor of anxiety and depression with a sensitivity and specificity of 88% (95%CI, 64% to 99%) and 81% (95%CI, 65% to 92%), respectively. Pain correlated with HADS anxiety and depression scores (e.g. Rank correlation coefficients (Kendall's tau-b) between total HADS scores and Pain VAS scores 0.29; p=0.003). Disability was greater in patients with depression and/or anxiety (e.g. total HADS score; Kendall's rank correlation coefficient tau-b=0.26, p=0.007) OA severity as determined by radiological score was not a good predictor for anxiety nor depression and only weakly associated with disability. Anxiety and depression are very common in OA patients. HADS anxiety was a better predictor of diagnosed anxiety than HADS depression was of diagnosed depression. HADS is a valid and reliable screening instrument for detecting mood disorder, but not a diagnostic tool or a substitute for asking about symptoms of depression. The interrelationship between mental health, pain and disability is strong. We should therefore adopt a multidisciplinary approach to the management of OA.

Medically unexplained pain complaints are associated with underlying unrecognized mood disorders in primary care

BACKGROUND

Patients with chronic pain frequently display comorbid depression, but the impact of this concurrence is often underestimated and mistreated. The aim of this study was to determine the prevalence of unrecognized major depression and other mood disorders and comorbid unexplained chronic pain in primary care settings and to explore the associated factors.Also, to compare the use of health services by patients with unexplained chronic pain, both with and without mood disorder comorbidity.

METHODS

A cross-sectional study was carried out in a sample of primary care centers. 3189 patients consulting for "unexplained chronic pain" were assessed by the Visual Analogue Scales (VAS) and the Primary Care Evaluation of Mental Disorders (PRIME-MD) questionnaire.

RESULTS

We report: a) a high prevalence of unrecognized mood disorders in patients suffering from unexplained chronic pain complaints (80.4%: CI 95%: 79.0%; 81.8%); b) a greater susceptibility of women to mood disorders (OR adjusted = 1.48; CI 95%:1.22; 1.81); c) a direct relationship between the prevalence of mood disorders and the duration of pain (OR adjusted = 1.01; CI 95%: 1.01; 1.02) d) a higher comorbidity with depression if the pain etiology was unknown (OR adjusted = 1.74; CI 95%: 1.45; 2.10) and, e) an increased use of health care services in patients with such a comorbidity (p < 0.0001).

CONCLUSIONS

The prevalence of undiagnosed mood disorders in patients with unexplained chronic pain in primary care is very high, leading to dissatisfaction with treatment processes and poorer outcomes. Consequently, it seems necessary to explore this condition more regularly in general practice in order to reach accurate diagnoses and to select the appropriate treatment.

Pain perception in patients with bipolar disorder and schizophrenia

OBJECTIVE

Pain perception is reported to be altered in patients with depression and schizophrenia. However, few studies have investigated the pain perception in patients with bipolar disorders. We therefore aimed to compare pain sensitivity between patients with bipolar disorder, schizophrenia and controls.

METHODS

Study groups consisted of 30 patients with bipolar disorder, and control groups consisted of 27 patients with schizophrenia and 59 healthy subjects. Pain perception was assessed with cold pressor test (CPT) by exposure to ice-water.

RESULTS

Patients with schizophrenia had significantly higher pain thresholds (PTh) than patients with bipolar disorder. There were no differences between the PTh of patients with schizophrenia and healthy control subjects. However, patients with bipolar disorder had significantly lower pain tolerance (PT) in the CPT than patients with schizophrenia and corresponding healthy control subjects.

CONCLUSIONS

The higher PTh in the schizophrenia group compared with the bipolar group found in this study supports further investigation of a potential difference in the pain perception between patients with schizophrenia and bipolar disorder. Theoretical implications of these findings and possible relevant behavioural and neurochemical mechanisms are discussed.