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Inmaculada Failde,1,2 María Dueñas,2,3 Maria Victoria Ribera,4 Rafael Gálvez,5 Juan A Mico,2,6,7 Alejandro Salazar,2,3 Helena de Sola,1,2 Concepción Pérez8 1Department of Biomedicine, Biotechnology and Public Health, Faculty of Medicine, University of Cádiz, Cádiz, Spain; 2Institute of Research and Innovation in Biomedical Sciences of the Province of Cadiz, Spain; 3Department of Statistics and Operational Research, Faculty of Sciences, University of Cádiz, Cádiz, Spain; 4Pain Clinic, Hospital Vall d’Hebrón, Barcelona, Spain; 5Pain Clinic, Hospital Virgen de las Nieves, Granada, Spain; 6Department of Neuroscience, Pharmacology and Psychiatry, Faculty of Medicine, University of Cádiz, Cádiz, Spain; 7CIBER of Mental Health, CIBERSAM, Instituto de Salud Carlos III, Madrid, Spain; 8Pain Unit, Hospital de la Princesa, Madrid, Spain 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. Keywords: central neuropathic pain, peripheral neuropathic pain, pain intensity, quality of life

This review provides a brief summary of what is known about the anxiolytic mechanism of action of pregabalin, a highly selective, high-affinity ligand of the P/Q type of voltage-gated calcium channel (CaV). Evidence from in vivo models of neuronal hyperexcitability suggests that pregabalin reduces synaptic release of neurotransmitters in selected CNS regions including the cortex, olfactory bulb, hypothalamus, amygdala, hippocampus, cerebellum and dorsal horn of the spinal cord. Release of neurotransmitters from the synaptic vesicle, and propagation of neurotransmission, requires the vesicle to fuse with the presynaptic membrane. Pregabalin binding to the α(2)δ type 1 protein of the P/Q type CaV reduces the availability of Ca2+ required for membrane fusion and exocytosis of neurotransmitters. Evidence that the anxiolytic mechanism of action of pregabalin is mediated by binding to the α(2)δ type 1 protein comes from animal models, which have demonstrated a structure-activity relationship between the affinity of ligands for the α(2)δ type 1 protein and their potency in models of anxiety such as the Vogel conflict test. Furthermore, the anxiolytic activity of pregabalin is lost in transgenic mice with specific point mutations in the CaV α(2)δ type 1 protein. Pregabalin-mediated reduction in calcium currents has also been shown to result in a significant inhibition of the release of neurotransmitters implicated in pathological anxiety such as glutamate and monoamine neurotransmitters. However, further research is needed to confirm that these effects contribute to the anxiolytic mechanism of action of pregabalin. Finally, pregabalin may also act by inhibiting synaptogenesis of excitatory neurons formed in response to chronic stress or anxiety, or more acutely inhibit the trafficking of CaV to the plasma membrane. [ABSTRACT FROM AUTHOR]

María Dueñas,1 Begoña Ojeda,2 Alejandro Salazar,2 Juan Antonio Mico,3 Inmaculada Failde,2 1Nursing Faculty “Salus Infirmorum”, The Observatory of Pain, University of Cádiz, Cádiz, Spain; 2Preventive Medicine and Public Health Area, The Observatory of Pain, University of Cádiz, Cádiz, Spain; 3Department of Neuroscience, Pharmacology, and Psychiatry, CIBER of Mental Health, CIBERSAM, Institute of Health Carlos III, University of Cádiz, Cádiz, Spain Abstract: Chronic pain (CP) seriously affects the patient’s daily activities and quality of life, but few studies on CP have considered its effects on the patient’s social and family environment. In this work, through a review of the literature, we assessed several aspects of how CP influences the patient’s daily activities and quality of life, as well as its repercussions in the workplace, and on the family and social environment. Finally, the consequences of pain on the health care system are discussed. On the basis of the results, we concluded that in addition to the serious consequences on the patient’s life, CP has a severe detrimental effect on their social and family environment, as well as on health care services. Thus, we want to emphasize on the need to adopt a multidisciplinary approach to treatment so as to obtain more comprehensive improvements for patients in familial and social contexts. Accordingly, it would be beneficial to promote more social- and family-oriented research initiatives. Keywords: pain, everyday problems, social relationships, family environment, health services

BACKGROUND: A new transdermal delivery system (TDS) for the rate-controlled systemic delivery of buprenorphine is available in 3 patch strengths, with release rates of 35, 52.5, and 70 microg/h over 72 hours, delivering daily amounts of 0.8, 1.2, and 1.6 mg, respectively. Randomized, double-blind, placebo-controlled, Phase III clinical trials in >400 patients with severe pain of malignant or nonmalignant origin have shown the analgesic efficacy of buprenorphine TDS. OBJECTIVE: This study investigated the effectiveness and tolerability of buprenorphine TDS for the relief of chronic pain in routine clinical practice. METHODS: This was a multicenter, open-label, uncontrolled, prospective, observational, 3-month follow-up study in patients who were beginning buprenorphine TDS treatment for moderate to severe cancer or noncancer pain that had not responded to nonopioid analgesics. Patches were to be changed every 72 hours. Patients were evaluated at 1 and 3 months after the start of treatment. Those who dropped out were considered treatment failures. Pain relief was assessed on a 5-category verbal rating scale, and quality of life was assessed using the European Quality of Life 5D (EQ-5D) questionnaire. Tolerability was determined based on adverse events recorded during the follow-up period. RESULTS: The study recruited 1223 patients, most of whom were outpatients. Of the 1212 patients for whom sex data were available, 820 (67.7%) were women. In the 1188 patients with age data, the mean (SD) age was 64.9 (12.9) years. In the 1175 patients with data on the etiology of pain, 82.4% had noncancer pain. Six hundred eighty-eight (56.3%) patients completed the 3-month follow-up period. The median daily amount of buprenorphine TDS received at the beginning of the study was 0.8 mg (corresponding to 35 microg/h). Over the study period, there was a significant increase in the proportion of patients reporting very good or good pain relief (P < 0.001), from 3.6% (43/1205) at baseline to 63.2% (762/1205) after 1 month and 56.8% (685/1205) after 3 months. Quality of life also improved, from a mean (SD) EQ-5D score of 40.6 (20.5) at baseline to 56.8 (23.5) at 3 months (P < 0.001). Five hundred seventeen (42.3%) of the original 1223 patients experienced adverse events; the investigator judged 397 (32.5%) of these events possibly or probably related to study drug. The likelihood of experiencing a drug-related adverse event was greater in noncancer patients than in cancer patients. The most common adverse events were nausea (11.0%), vomiting (9.2%), and constipation (7.8%); the most common local adverse events were pruritus (1.4%), dermatitis (1.3%), and erythema (1.3%). CONCLUSION: In the population studied, buprenorphine TDS was effective in alleviating cancer and noncancer pain and was well tolerated overall. [ABSTRACT FROM AUTHOR]

Objective: To improve understanding of current practices in the treatment of children and adolescents with chronic pain in Spain., Methods: A web-based survey was conducted with a representative sample of healthcare professionals (i.e. general practitioners [GP] and pediatricians [P]) in Spain. The survey included 23 questions on the pain education and training they had been given, and on organizational issues and current practices in the assessment and management of children and adolescents with chronic pain in their current work., Results: The survey was completed by 191 professionals (75 GP and 116 P) with wide experience (mean number of years = 21; SD = 8) in the management of children and adolescents with chronic pain. Half of the participants reported that they had not been given any specific education or training on pediatric chronic pain management during their studies, and 80% acknowledged important gaps in their training. Although the majority assessed pain when attending children with chronic pain (80%), and almost all (96%) believed that protocols to guide the management of chronic pain in young people were necessary, only a third reported that they usually use a specific protocol. Less than 25% were part of a multidisciplinary team addressing the needs of children and adolescents with chronic pain., Conclusions: This survey has identified considerable limitations in the management of children and adolescents with chronic pain in Spain. This information can now be used by policy makers to improve the care given to children and adolescents suffering from chronic pain and their families.

Monoamines are involved in regulating the endogenous pain system and indeed, peripheral and central monoaminergic dysfunction has been demonstrated in certain types of pain, particularly in neuropathic pain. Accordingly, drugs that modulate the monaminergic system and that were originally designed to treat depression are now considered to be first line treatments for certain types of neuropathic pain (e.g., serotonin and noradrenaline (and also dopamine) reuptake inhibitors). The analgesia induced by these drugs seems to be mediated by inhibiting the reuptake of these monoamines, thereby reinforcing the descending inhibitory pain pathways. Hence, it is of particular interest to study the monoaminergic mechanisms involved in the development and maintenance of chronic pain. Other analgesic drugs may also be used in combination with monoamines to facilitate descending pain inhibition (e.g., gabapentinoids and opioids) and such combinations are often also used to alleviate certain types of chronic pain. By contrast, while NSAIDs are thought to influence the monoaminergic system, they just produce consistent analgesia in inflammatory pain. Thus, in this review we will provide preclinical and clinical evidence of the role of monoamines in the modulation of chronic pain, reviewing how this system is implicated in the analgesic mechanism of action of antidepressants, gabapentinoids, atypical opioids, NSAIDs and histaminergic drugs., (Copyright © 2019 Bravo, Llorca-Torralba, Berrocoso and Micó.)

Oxidative stress is a pathophysiological mechanism potentially involved in psychiatric disorders. The objective of this study was to assess the relationship between total antioxidant status (TAS) and the functional status of patients with a first episode of psychosis at the onset of the disease. For this purpose, a sample of 70 patients aged between 9 and 17 years with a first episode of psychosis were followed up for a period of two years. Blood samples were drawn to measure TAS levels at three time points: at baseline, at one year, and at two years. Clinical symptoms and functioning were also assessed at the same time points using various scales. Linear regression analysis was performed to investigate the relationship between TAS and clinical status at each assessment, adjusting for potential confounding factors. The distribution of clinical variables was grouped in different percentiles to assess the dose-response in the relation between clinical variables and TAS. At baseline, patient's score on Children's Global Assessment Scale (CGAS) was directly and significantly associated with TAS with a monotonic increase in percentiles, and surprising this association was reversed after one and two years of follow-up with a monotonic decrease. In summary at the onset of the illness, TAS is positively related to clinical status, whereas as the illness progresses this correlation is reversed and becomes negative. This may be the result of an adaptive response.

Neuropathic pain, resistant to opiates and other drugs, is a chronic/persistent state with a complex treatment and often poor efficacy. In this scenario, cannabinoids are increasingly regarded as a genuine alternative. In this paper, and in an experimental animal model of neuropathic pain, we studied the efficacy of three kinds of PLGA nanoparticles containing synthetic cannabinoid CB13: (i) plain nanoparticles (PLGA); (ii) particles coated with PEG chains (PLGA+PEG) and (iii) particles possessing hydrophilic surfaces obtained by covalently binding PEG chains (PLGA-PEG). The optimized formulation, CB13-PLGA-PEG, showed high drug loading (13%) and small size (<300nm) with a narrow distribution and controlled surface properties (near-neutral zeta potential and stable PEG corona). Animal nociceptive behavioral studies were conducted by paw pressure and acetone tests. Versus the free CB13, CB13-PLGA-PEG nanoparticles showed a very noticeable analgesic efficacy with the longest sustained pain-relieving effect, lasting up to eleven days after one oral dose., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Objective: To analyze the use of healthcare resources by chronic pain (CP) patients in Spain and their satisfaction with them., Research Design and Methods: A nationwide, cross-sectional study was carried out on a representative sample of 1957 Spanish adults. A telephone survey was conducted with the aim of analyzing the prevalence of CP, the characteristics and consequences of pain, the use of healthcare resources and patients' satisfaction with them. Descriptive, bivariate and multivariate analyses were performed., Results: Of the 1957 subjects interviewed, 325 suffered CP. The mean duration of CP was 10 years (SD: 11.3) and 48.9% of the CP sufferers reported severe/unbearable pain. Moreover, about 30% felt sad/very sad or anxious/very anxious, 24.4% had been on sick leave, 12% had left/lost their jobs and 47.2% considered their pain affected their families. Likewise, 92.9% had consulted a healthcare professional due to their CP, on average 3.49 times (SD: 3.9), and 69.2% took medication. In addition, 67.3% and 63.8% were satisfied/very satisfied with the care and the healthcare information they received, respectively. Individuals who reported headache (OR = 0.34) and feeling sad (OR =0.38) were least satisfied with the care they received. In addition, CP sufferers who made greater use of consultations were those who had left/lost their jobs (β = 1.44), those who took medication (β = 1.67), those who considered their pain affected their families (β = 0.97) and those with a shorter duration of pain (β = -0.003)., Conclusions: CP produces relevant demands on healthcare resources, conditioned by the consequences within the family and the effects on their employment. To achieve greater patient satisfaction, professionals need to pay particular attention to certain sites of pain and to patients' mental health.

Alterations in the innate inflammatory response may underlie the pathophysiology of psychiatric diseases. Current antipsychotics modulate pro-/anti-inflammatory pathways, but their specific actions on these pathways remain only partly explored. This study was conducted to elucidate the regulatory role of paliperidone (1 mg/kg i.p.) on acute (6 h) and chronic (6 h/day for 21 consecutive days) restraint stress-induced alterations in 2 emerging endogenous anti-inflammatory/antioxidant mechanisms: nuclear factor erythroid-related factor 2 (NRF2)/antioxidant enzymes pathway, and the cytokine milieu regulating M1/M2 polarization in microglia, analyzed at the mRNA and protein levels in prefrontal cortex samples. In acute stress conditions, paliperidone enhanced NRF2 levels, possibly related to phosphoinositide 3-kinase upregulation and reduced kelch-Like ECH-associated protein 1 expression. In chronic conditions, paliperidone tended to normalize NRF2 levels through a phosphoinositide 3-kinase related-mechanism, with no effects on kelch-Like ECH-associated protein 1. Antioxidant response element-dependent antioxidant enzymes were upregulated by paliperidone in acute stress, while in chronic stress, paliperidone tended to prevent stress-induced downregulation of the endogenous antioxidant machinery. However, paliperidone increased transforming growth factor-β and interleukin-10 in favor of an M2 microglia profile in acute stress conditions, which was also corroborated by paliperidone-induced increased levels of the M2 cellular markers arginase I and folate receptor 2. This latter effect was also produced in chronic conditions. Immunofluorescence studies suggested an increase in the number of microglial cells expressing arginase I and folate receptor 2 in the stressed animals pretreated with paliperidone. In conclusion, the enhancement of endogenous antioxidant/anti-inflammatory pathways by current and new antipsychotics could represent an interesting therapeutic strategy for the future., Competing Interests: Compliance with ethical standards Required Author Forms Disclosure forms provided by the authors are available with the online version of this article.

Background: To investigate baseline demographics and disease characteristics as predictors of the analgesic effect of duloxetine and pregabalin on diabetic peripheral neuropathic pain (DPNP)., Methods: Based on data from the COMBO-DN study, a multinational clinical trial in DPNP, the potential impact of baseline characteristics on pain relief after 8-week monotherapy with 60 mg/day duloxetine or 300 mg/day pregabalin was assessed using analyses of covariance. Subgroups of interest were characterized regarding their baseline characteristics and efficacy outcomes., Results: A total of 804 patients were evaluated at baseline. A significant interaction with treatment was observed in the mood symptom subgroups with a larger pain reduction in duloxetine-treated patients having no mood symptoms [Hospital Anxiety and Depression Scale (HADS) depression or anxiety subscale score <11; -2.33 (duloxetine); -1.52 (pregabalin); p = 0.024]. There were no significant interactions between treatment for subgroups by age (<65 or ≥65 years), gender, baseline pain severity [Brief Pain Inventory Modified Short Form (BPI-MSF) average pain <6 or ≥6], diabetic neuropathy duration (≤2 or >2 years), baseline haemoglobin A1c (HbA1c) (<8% or ≥8%), presence of comorbidities and concomitant medication use., Conclusions: Our analyses suggest that the efficacy of duloxetine and pregabalin for initial 8-week treatment in DPNP was consistent across examined subgroups based on demographics and disease characteristics at baseline except for the presence of mood symptoms. Duloxetine treatment appeared to be particularly beneficial in DPNP patients having no mood symptoms., (© 2015 European Pain Federation - EFIC®)

Objective: This study aims to assess the prevalence of chronic pain, its characteristics, and its impact on the general Spanish population. Also, to establish chronic pain patient subgroups according to the characteristics of pain and to identify variables specifically associated with each subgroup., Design: Telephone-based, cross-sectional nationwide study., Subjects: A sample of 1,957 individuals representative of the Spanish population., Methods: Data were collected through telephone interviews. A subject was considered to have chronic pain if they had suffered pain (at least 4 days a week) during the last 3 months. The subjects were divided into two subgroups through a cluster analysis, and a regression model was established to determine the variables most specifically associated with these subgroups., Results: The prevalence of chronic pain was 16.6% (95% confidence interval: 14.9-18.3) and among these subjects, more than 50% referred to limitations in their daily activities, 30% felt sad and/or anxious, and 47.2% indicated that their pain was affecting their family life. Two subgroups of subjects with pain were identified: 1) characterized by generalized pain in more than one location and of a long evolution (150 months); and 2) characterized by pain localized to only one site with a shorter duration (100 months). Individuals who felt anxious because of their pain and those who considered that their pain was affecting their family were more likely to belong to group 1., Conclusions: Pain affects an important proportion of the Spanish adult population and that it has a strong personal impact. Two pain groups were clearly distinguished by their clinical characteristics., (Wiley Periodicals, Inc.)

Background: The corticotropin-releasing factor is a stress-related neuropeptide that modulates locus coeruleus activity. As locus coeruleus has been involved in pain and stress-related patologies, we tested whether the pain-induced anxiety is a result of the corticotropin-releasing factor released in the locus coeruleus., Methods: Complete Freund's adjuvant-induced monoarthritis was used as inflammatory chronic pain model. α-Helical corticotropin-releasing factor receptor antagonist was microinjected into the contralateral locus coeruleus of 4-week-old monoarthritic animals. The nociceptive and anxiety-like behaviors, as well as phosphorylated extracellular signal-regulated kinases 1/2 and corticotropin-releasing factor receptors expression, were quantified in the paraventricular nucleus and locus coeruleus., Results: Monoarthritic rats manifested anxiety and increased phosphorylated extracellular signal-regulated kinases 1/2 levels in the locus coeruleus and paraventricular nucleus, although the expression of corticotropin-releasing factor receptors was unaltered. α-Helical corticotropin-releasing factor antagonist administration reversed both the anxiogenic-like behavior and the phosphorylated extracellular signal-regulated kinases 1/2 levels in the locus coeruleus., Conclusions: Pain-induced anxiety is mediated by corticotropin-releasing factor neurotransmission in the locus coeruleus through extracellular signal-regulated kinases 1/2 signaling cascade., (© The Author 2015. Published by Oxford University Press on behalf of CINP.)

To assess the impact of chronic pain on the family environment from the patient's, relative's and caregiver's perspective, we undertook cross-sectional study on a representative sample of Spanish adults who suffered pain at least 4 days a week for ≥3 months and on relatives and caregivers of patients that fulfilled these criteria. The characteristics of pain and the perception of its impact on the family environment were assessed, using logistic regression models to reveal the variables associated with the impact of pain on the family. From a total of 1,957 subjects, 325 experienced chronic pain and 34.6% of them perceived that their pain affected their family environment. These patients recognized a stronger impact when their relatives were sad (OR = 3.61; CI:1.57, 8.27) and had modified the leisure activities because of the pain (OR = 3.62; CI:1.56, 8.38). Among the 131 relatives, 51.2% perceived that pain was affecting the family, causing changes in their leisure activities (OR = 1.17; CI:1.04, 9.94) and sleep disturbance (OR = 1.40; CI:1.32, 12.58). Of the 36 caregivers, mainly women over 50 years of age, 66.7% indicated that pain affected the family, although 72.8% were satisfied with the help they provided. Chronic pain has a very strong impact on the family, although this is perceived distinctly by patients, relatives, and caregivers. Recognizing that factors related to pain affect the family's well-being, and adopting a global approach to pain that takes into consideration the family's experiences, should improve the therapeutic response, and enhance the patient's and relative's quality of life. (PsycINFO Database Record (c) 2014 APA, all rights reserved).

Background: Previous studies indicated a systemic deregulation of the pro-/antiinflammatory balance in subjects after 6 months of a first psychotic episode. This disruption was reexamined 12 months after diagnosis to identify potential risk/protective factors and associations with symptom severity., Methods: Eighty-five subjects were followed during 12 months and the determination of the same pro-/antiinflammatory mediators was carried out in plasma and peripheral blood mononuclear cells. Multivariate logistic regression analyses were used to identify risk/protective factors. Multiple linear regression models were performed to detect the change of each biological marker during follow-up in relation to clinical characteristics and confounding factors., Results: This study suggests a more severe systemic pro-/antiinflammatory deregulation than in earlier pathological stages in first psychotic episode, because not only were intracellular components of the inflammatory response increased but also the majority of soluble elements. Nitrite plasma levels and cyclooxygenase-2 expression in peripheral blood mononuclear cells are reliable potential risk factors and 15d-prostaglandin-J2 plasma levels a protection biomarker. An interesting relationship exists between antipsychotic dose and the levels of prostaglandin-E2 (inverse) and 15d-prostaglandin-J2 (direct). An inverse relationship between the Global Assessment of Functioning scale and lipid peroxidation is also present., Conclusions: Summing up, pro-/antiinflammatory mediators can be used as risk/protection biomarkers. The inverse association between oxidative/nitrosative damage and the Global Assessment of Functioning scale, and the possibility that one of the targets of antipsychotics could be the restoration of the pro-/antiinflammatory balance support the use of antiinflammatory drugs as coadjuvant to antipsychotics., (© The Author 2015. Published by Oxford University Press on behalf of CINP.)

Sensory profiles are heterogeneous in neuropathic pain disorders, and subgroups of patients respond differently to treatment. To further explore this, patients in the COMBO-DN study were prospectively assessed by the Neuropathic Pain Symptom Inventory (NPSI) at baseline, after initial 8-week therapy with either duloxetine or pregabalin, and after subsequent 8-week combination/high-dose therapy. Exploratory post hoc cluster analyses were performed to identify and characterize potential subgroups through their scores in the NPSI items. In patients not responding to initial 60 mg/d duloxetine, adding 300 mg/d pregabalin for combination treatment was particularly effective regarding the dimensions pressing pain and evoked pain, whereas maximizing the duloxetine dose to 120 mg/d appeared more beneficial regarding paresthesia/dysesthesia. In contrast, adding 60 mg/d duloxetine to 300 mg/d pregabalin in case of nonresponse to initial pregabalin led to numerically higher decreases in all NPSI dimensions/items compared to maximizing the pregabalin dose to 600 mg/d. Cluster analysis revealed 3 patient clusters (defined by baseline scores for the 10 NPSI sensory items) with different pain profiles, not only in terms of overall pain severity, but also across NPSI items. Mean Brief Pain Inventory average pain improved in all clusters during combination/high-dose therapy. However, in patients with severe pain, the treatment effect showed a trend in favor of high-dose monotherapy, whereas combination therapy appeared to be more beneficial in patients with moderate and mild pain (not significant). These complementary exploratory analyses further endorse the idea that sensory phenotyping might lead to a more stratified treatment and potentially to personalized pain therapy., (Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.)

The hippocampus is a brain area characterized by its high plasticity, observed at all levels of organization: molecular, synaptic, and cellular, the latter referring to the capacity of neural precursors within the hippocampus to give rise to new neurons throughout life. Recent findings suggest that promoter methylation is a plastic process subjected to regulation, and this plasticity seems to be particularly important for hippocampal neurogenesis. We have detected the enzyme GNMT (a liver metabolic enzyme) in the hippocampus. GNMT regulates intracellular levels of SAMe, which is a universal methyl donor implied in almost all methylation reactions and, thus, of prime importance for DNA methylation. In addition, we show that deficiency of this enzyme in mice (Gnmt-/-) results in high SAMe levels within the hippocampus, reduced neurogenic capacity, and spatial learning and memory impairment. In vitro, SAMe inhibited neural precursor cell division in a concentration-dependent manner, but only when proliferation signals were triggered by bFGF. Indeed, SAMe inhibited the bFGF-stimulated MAP kinase signaling cascade, resulting in decreased cyclin E expression. These results suggest that alterations in the concentration of SAMe impair neurogenesis and contribute to cognitive decline., (© 2014 Wiley Periodicals, Inc.)

The objective of the study is to examine the association of baseline total antioxidant status (TAS) and glutathione (GSH) levels with short- and long-term cognitive functioning in patients with early onset first-episode psychosis, comparing affective and non-affective psychoses. We analysed 105 patients with an early onset-first episode psychosis (age 9-17 years) and 97 healthy controls. Blood samples were taken at admission for measurement of TAS and GSH, and cognitive performance was assessed at baseline and at 2years of follow-up. Regression analysis was used to assess the relationship between TAS/GSH levels at baseline and cognitive performance at both time points, controlling for confounders. Baseline TAS and GSH levels were significantly lower in patients than healthy controls. In patients, baseline TAS was positively associated with the global cognition score at baseline (p=0.048) and two years later (p=0.005), while TAS was not associated with cognitive functioning in healthy controls. Further, baseline TAS in patients was specifically associated with the memory domain at baseline and with the memory and attention domains two years later. Stratifying by affective and non-affective psychoses, significant associations were only found between TAS and cognition in the non-affective psychosis group. Baseline GSH levels were not associated with cognitive functioning at either time point in either group. The antioxidant defence capacity in early onset first-episode psychotic patients is directly correlated with global cognition at baseline and at 2years of follow-up, especially in non-affective psychosis., (Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.)

Background: Schizophrenia is a chronic syndrome of unknown etiology, predominantly defined by signs of psychosis. The onset of the disorder occurs typically in late adolescence or early adulthood. Efforts to study pathophysiological mechanisms in early stages of the disease are crucial in order to prompt intervention., Methods: Case-control study of first-episode psychotic (FEP) patients and matched controls. We recruited 117 patients during the first year after their FEP according to the DSM-IV criteria and recruited 106 gender-, race-, and age-matched controls between September 2010 and June 2011., Results: Biochemical studies carried out in peripheral mononuclear blood cells (PMBC) and plasma evidence a significant increase in intracellular components of a main proinflammatory pathway, along with a significant decrease in the anti-inflammatory ones. Multivariate logistic regression analyses identified the expression of inducible isoforms of nitric oxide synthase and cyclooxygenase in PMBC and homocysteine plasma levels as the most reliable potential risk factors and the inhibitor of the inflammatory transcription factor NFκB, IκBα, and the anti-inflammatory prostaglandin 15d-PGJ2 as potential protection factors., Discussion: Taken as a whole, the results of this study indicate robust phenotypical differences at the cellular machinery level in PMBC of patients with FEP. Although more scientific evidence is needed, the determination of multiple components of pro- and anti-inflammatory cellular pathways including the activity of nuclear receptors has interesting potential as biological markers and potential risk/protective factors for FEP. Due to its soluble nature, a notable finding in this study is that the anti-inflammatory mediator 15d-PGJ2 might be used as plasmatic biomarker for first episodes of psychosis.

Background and Aims: Epidemiological data about neuropathic pain are still scarce. A national survey, based on neurologic clinical diagnosis, was performed to determine its prevalence among patients attending pain clinics., Methods: An epidemiological cross-sectional study involving pain clinics across all regions in Spain was carried out. Pain specialists evaluated the medical files and the clinical condition of patients attending their practices systematically during 1 day. They used the revised definition and grading system proposed in 2008 to decide whether a given patient had definite (i.e., confirmed), probable (potential) or possible (believed) neuropathic pain. Also, they provided a diagnostic label for neuropathic pain conditions and appraised treatment adequacy., Results: In a single day, 178 pain specialists provided data from 2173 patients. Definite, probable and possible neuropathic pain was cited in 639 (29.4%), 304 (14.0%) and 97 (4.5%) patients, respectively. Almost two-thirds of these were women. A diagnostic label of primary pure central and/or peripheral neuropathic pain was cited in 344 (15.8%) patients. The most common diagnostic label (568 patients) was low back pain or sciatica causing mixed neuropathic pain. Definite neuropathic pain diagnosis was less likely in patients with mixed pain conditions and in women derived from primary care. Co-morbid depressive or anxiety symptoms were usual., Conclusions: Definite (confirmed) neuropathic pain alone was as prevalent as neuropathic pain ascertained with screening questionnaires in prior recent European studies. The clinical relevance of the surplus of patients with potential and believed neuropathic pain ascertained by clinicians is uncertain., (© 2012 European Federation of International Association for the Study of Pain Chapters.)

Unlabelled: Inflammation, caused by both external and endogenous factors, has been implicated as a main pathophysiological feature of chronic mental illnesses, including schizophrenia. An increase in pro-inflammatory cytokines has been described both in experimental models and in schizophrenia patients. However, not much is known about the effects that antipsychotic drugs have on intra- and intercellular mechanisms controlling inflammation. The aim of the present study was to investigate the possible anti-inflammatory effect of a standard schizophrenia treatment not only at the level of soluble mediators, but also at intra- and intercellular inflammatory pathways. The present study was conducted in a model of mild neuroinflammation using a lipopolysaccharide (LPS) challenge that was not an endotoxaemic dose (0.5 mg/kg i.p.) in young adult rats., Main Results: single doses of risperidone (0.3-3.0 mg/kg i.p.) prevented increased inflammatory parameters induced by LPS in brain cortex [expression of inflammatory cytokines, interleukin (IL)-1β and tumour necrosis factor (TNF)-α, activity of the inducible inflammatory enzymes nitric oxide synthase and cyclooxygenase, p38 mitogen-activated protein kinase (MAPK) and inflammatory nuclear transcription factor κB] and restored anti-inflammatory pathways decreased by LPS challenge (deoxyprostaglandins and peroxisome proliferator activated receptor γ). This is the first study demonstrating that risperidone elicits a preventive effect on the anti-inflammatory arm of the homeostatic mechanism controlling inflammation in a model of mild encephalitis in rats. Our findings suggest a possible protective effect of risperidone on brain cells.

Overexpression of the mammalian homolog of the unc-18 gene (munc18-1) has been described in the brain of subjects with schizophrenia. Munc18-1 protein is involved in membrane fusion processes, exocytosis and neurotransmitter release. A transgenic mouse strain that overexpresses the protein isoform munc18-1a in the brain was characterized. This animal displays several schizophrenia-related behaviors, supersensitivity to hallucinogenic drugs and deficits in prepulse inhibition that reverse after antipsychotic treatment. Relevant brain areas (that is, cortex and striatum) exhibit reduced expression of dopamine D(1) receptors and dopamine transporters together with enhanced amphetamine-induced in vivo dopamine release. Magnetic resonance imaging demonstrates decreased gray matter volume in the transgenic animal. In conclusion, the mouse overexpressing brain munc18-1a represents a new valid animal model that resembles functional and structural abnormalities in patients with schizophrenia. The animal could provide valuable insights into phenotypic aspects of this psychiatric disorder.

Background: Stressful challenges are associated with variations in immune parameters, including increased innate immunity/inflammation. Among possible mechanisms through which brain monitors peripheral immune responses, toll-like receptors (TLRs) recently emerged as the first line of defense against invading microorganisms. Their expression is modulated in response to pathogens and other environmental stresses., Methods: Taking into account this background, the present study aimed to elucidate whether the toll-like receptor-4 (TLR-4) signaling pathway is activated after repeated restraint/acoustic stress exposure in mice prefrontal cortex (PFC), the potential regulatory mechanism implicated (i.e., bacterial translocation), and its role in conditions of stress-induced neuroinflammation, using a genetic strategy: C3H/HeJ mice with a defective response to lipopolysaccharide stimulation of TLR-4., Results: Stress exposure upregulates TLR-4 pathway in mice PFC. Stress-induced inflammatory nuclear factor κB activation, upregulation of the proinflammatory enzymes nitric oxide synthase and cyclooxygenase type 2, and cellular oxidative/nitrosative damage are reduced when the TLR-4 pathway is defective. Conversely, TLR-4 deficient mice presented higher levels of the anti-inflammatory nuclear factor peroxisome proliferator activated receptor-gamma after stress exposure than control mice. The series of experiments using antibiotic intestinal decontamination also suggest a role for bacterial translocation on TLR-4 activation in PFC after stress exposure., Conclusions: Taken together, all the data presented here suggest a bifunctional role of TLR-4 signaling pathway after stress exposure by triggering neuroinflammation at PFC level and regulating gut barrier function/permeability. Furthermore, our data suggest a possible protective role of antibiotic decontamination in stress-related pathologies presenting increased intestinal permeability (leaky gut) such as depression, showing a potential therapeutic target that deserves further consideration., (Copyright © 2013 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.)

Background: Our objective was to determine antioxidant defence activity in healthy controls (HC) and healthy unaffected second-degree relatives of patients with early onset psychosis (HC-FHP), and to assess its relationship with familiar environment measured using the Family Environment Scale (FES)., Methods: We included 82 HC and 14 HC-FHP aged between 9 and 17 years. Total antioxidant status, lipid peroxidation, antioxidant enzyme activities and glutathione levels were determined in blood samples., Results: There was a significant decrease in the total antioxidant level in the HC-FHP group compared with the HC group (OR = 2.94; p = 0.009), but no between-group differences in the Global Assessment of Functioning (GAF) scale scores. For the FES, the HC-FHP group had significantly higher scores in the cohesion (p = 0.007) and intellectual-cultural dimensions (p=0.025). After adjusting for these two FES dimensions, total antioxidant status remained significantly different between groups (OR = 10.86, p = 0.009)., Conclusions: Although causal relationships cannot be assumed, we can state that family environment is not playing a role in inducing oxidative stress in these healthy subjects. It could be hypothesized that families with affected relatives protect themselves from psychosis with positive environmental factors such as cohesion and intellectual-cultural activities.

Progressive loss of cortical gray matter (GM), as measured by magnetic resonance imaging, has been described early in the course of first-episode psychosis. This study aims to assess the relationship between oxidative balance and progression of cortical GM changes in a multicenter sample of first-episode early-onset psychosis (EOP) patients from baseline to two-year follow-up. A total of 48 patients (13 females, mean age 15.9±1.5 years) and 56 age- and gender-matched healthy controls (19 females, 15.3±1.5 years) were assessed. Magnetic resonance imaging (MRI) scans performed both at the time of the first psychotic episode and 2 years later were used for volumetric measurements of left and right gray matter regions (frontal, parietal, and temporal lobes) and total sulcal cerebrospinal fluid (CSF). Total glutathione (GSH) blood levels were determined at baseline. In patients, after controlling for possible confounding variables, lower baseline GSH levels were significantly associated with greater volume decrease in left frontal (B=0.034, 95% confidence interval (CI): 0.011 to 0.056, r=0.620, p=0.006), parietal (B=0.039, 95% CI: 0.020 to 0.059, r=0.739, p=0.001), temporal (B=0.026, 95% CI: 0.016 to 0.036, r=0.779, p<0.001), and total (B=0.022, 95% CI: 0.014 to 0.031, r=0.803, p<0.001) gray matter, and with greater increase in total CSF (B=-0.560, 95% CI: -0.270 to -0.850, r=-0.722, p=0.001). Controls did not show significant associations between brain volume changes and GSH levels. GSH deficit during the first psychotic episode was related to greater loss of cortical GM two years later in patients with first-episode EOP, suggesting that oxidative damage may contribute to the progressive loss of cortical GM found in patients with first-episode psychosis., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Introduction: This study measures the levels of various markers of oxidative stress and inflammation in blood samples from first-episode psychosis (FEP) patients, and examines the association between these peripheral biomarkers and cognitive performance at 6 months after treatment., Methods: Twenty-eight FEP patients and 28 healthy controls (matched by age, sex and educational level) had blood samples taken at admission for assessment of total antioxidant status, superoxide dismutase (SOD), total glutathione (GSH), catalase (CAT), glutathione peroxidase, lipid peroxidation, nitrites and the chemokine monocyte chemoattractant protein-1 (MCP-1). A battery of cognitive tests was also applied to the healthy controls and those FEP patients who were in remission at 6 months after the acute episode., Results: FEP patients had significantly lower levels of total antioxidant status, catalase and glutathione peroxidase, compared with the healthy controls. Regression analyses found that MCP-1 levels were negatively associated with learning and memory (verbal and working), nitrite levels were negatively associated with executive function, and glutathione levels were positively associated with executive function., Conclusion: Our results suggest an association between certain peripheral markers of oxidative stress and inflammation and specific aspects of cognitive functioning in FEP patients. Further studies on the association between MCP-1 and cognition are warranted., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Background: There is a pressing need to identify novel pathophysiological pathways relevant to depression that can help to reveal targets for the development of new medications. Toll-like receptor 4 (TLR-4) has a regulatory role in the brain's response to stress. Psychological stress may compromise the intestinal barrier, and increased gastrointestinal permeability with translocation of lipopolysaccharide (LPS) from Gram-negative bacteria may play a role in the pathophysiology of major depression., Methods: Adult male Sprague-Dawley rats were subjected to chronic mild stress (CMS) or CMS+intestinal antibiotic decontamination (CMS+ATB) protocols. Levels of components of the TLR-4 signaling pathway, of LPS and of different inflammatory, oxidative/nitrosative and anti-inflammatory mediators were measured by RT-PCR, western blot and/or ELISA in brain prefrontal cortex. Behavioral despair was studied using Porsolt's test., Results: CMS increased levels of TLR-4 and its co-receptor MD-2 in brain as well as LPS and LPS-binding protein in plasma. In addition, CMS also increased interleukin (IL)-1β, COX-2, PGE2 and lipid peroxidation levels and reduced levels of the anti-inflammatory prostaglandin 15d-PGJ2 in brain tissue. Intestinal decontamination reduced brain levels of the pro-inflammatory parameters and increased 15d-PGJ2, however this did not affect depressive-like behavior induced by CMS., Conclusions: Our results suggest that LPS from bacterial translocation is responsible, at least in part, for the TLR-4 activation found in brain after CMS, which leads to release of inflammatory mediators in the CNS. The use of Gram-negative antibiotics offers a potential therapeutic approach for the adjuvant treatment of depression.

Background: Our objective is to determine the activity of the antioxidant defense system at admission in patients with early onset first psychotic episodes compared with a control group., Methods: Total antioxidant status (TAS) and lipid peroxidation (LOOH) were determined in plasma. Enzyme activities and total glutathione levels were determined in erythrocytes in 102 children and adolescents with a first psychotic episode and 98 healthy controls., Results: A decrease in antioxidant defense was found in patients, measured as decreased TAS and glutathione levels. Lipid damage (LOOH) and glutathione peroxidase activity was higher in patients than controls. Our study shows a decrease in the antioxidant defense system in early onset first episode psychotic patients., Conclusions: Glutathione deficit seems to be implicated in psychosis, and may be an important indirect biomarker of oxidative stress in early-onset schizophrenia. Oxidative damage is present in these patients, and may contribute to its pathophysiology.

Bipolar disorder is considered an important public health problem in the world. The depressive phase is the most important in terms of frequency, duration, and impairment of the quality of life. Common treatment of bipolar depression usually includes antidepressants, mood stabilizers and antipsychotics in different combinations, despite not having a specific indication for that. Quetiapine is the first drug in Europe that has obtained a specific indication for the treatment of bipolar depression, due to a pharmacologic profile that makes it to act on the three neurotransmitter systems involved in bipolar depression neurobiology. Regarding the dopaminergic pathway, quetiapine leads to an increasing of prefrontal dopamine release by antagonism of5-HT2A receptors, partial agonist of 5-HT1A and antagonism of a2 adrenoceptors. Quetiapine also enhances the serotoninergic transmission by increasing the density of receptors5-HT1A in the prefrontal cortex and by antagonism of 5-HT2A receptors and a2 adrenoceptors. On the other hand, norquetiapine, the main active metabolite of quetiapine, actsas a 5-HT2C antagonist and is a potent inhibitor of norepinephrine transporter (NET). NET inhibition leads to an increase of noerpinephrine in the synapse, and together with the increase of prefrontal dopamine and serotonin, could explain the antidepressive effect demonstrated by quetiapine in several clinical trials. Quetiapine’s action on glutamatergicand GABAergic receptors represents an interesting object of research, together with a potential neuroprotective effect that have already been observed in animal models.

Numerous studies support the participation of cytokines in the transmission of pain, especially in neuropathic pain. Results obtained both from different experimental pain models as well as studies from a clinical perspective implicate diverse cytokines, especially some of a proinflammatory nature, in the physiopathology of chronic pain. Selective pharmacologic manipulation of these pathways key molecules represents and constitutes a treatment opportunity and an answer to this painful pathology which currently has a difficult solution., (Copyright © 2009 Elsevier España, S.L. All rights reserved.)

Tricyclic antidepressants, together with anticonvulsants, are considered to be first-line drugs for the treatment of neuropathic pain. Antidepressants are analgesic in patients with chronic pain and no concomitant depression, indicating that the analgesic and antidepressant effects occur independently. The analgesia induced by these drugs seems to be centrally mediated but consistent evidence also indicates a peripheral site of action. Several pharmacological mechanisms account for their antinociceptive effect but the inhibition of monoamine transporters (and, consequently, the facilitation of descending inhibition pain systems) is implicated on the basis of mechanistic and knockout-mouse studies. However, pain is a common symptom of depression, and depression is frequent in chronic pain patients, supporting the hypothesis that pain and depression share some common biochemical mechanisms. We suggest that antidepressants have a genuine analgesic effect and that research into their mechanisms of action will help to facilitate the development of new drugs.

Tramadol is a centrally-acting analgesic endowed with opioid, noradrenergic and serotonergic properties. Various data suggest that, in addition to its analgesic effect, tramadol may have antidepressant and anxiolytic-like effects. This study investigates, through single-unit extracellular recording techniques, the in vivo effects of tramadol on locus coeruleus (LC) neurons and its possible effects on alpha(2)-adrenoceptors, opioid receptors and the 5-HT system. Tramadol produced a dose-dependent and complete inhibition of LC activity (ED(50)=2.1mg/kg). This inhibitory effect was prevented and reversed by the selective alpha(2)-adrenoceptor antagonist, idazoxan, but not by the opioid receptor antagonist, naloxone. The inhibition of the synthesis of 5-HT by p-chlorophenylalanine and the pre-administration of the 5-HT(1A) receptor agonist, 8-OH-DPAT at 40microg/kg, caused a significant potentiation of the tramadol effect decreasing the ED(50) by 53% and 67% respectively. Lower doses of 8-OH-DPAT, of 1 and 4microg/kg, did not significantly modify the tramadol effect. In summary, the results indicate that tramadol elicits an inhibitory effect on LC neurons in vivo through alpha(2)-adrenoceptors. Moreover, this effect is modulated by the 5-HT system and particularly by 5-HT(1A) receptors.

Cognitive deficit is a significant symptom in schizophrenic patients. Use of atypical antipsychotics has been demonstrated to improve some cognitive functions in schizophrenics, as well as in patients with dementia. However, side effects like sedation and muscarinic antagonism induced by these drugs have detracted from this improvement. We are interested in determining the behavioural effect of acute and chronic treatments with olanzapine and clozapine, two atypical antipsychotics, in a paradigm of working memory, and the influence on behavioural response of possible motor effects during test performance. Unspecific muscarinic antagonist scopolamine has been used for comparison. Male Wistar rats were trained on the 8-arm radial maze up to an accuracy level in choice of 80%. Distance travelled in the maze was also measured during test performance. Acute olanzapine, clozapine and scopolamine caused significant impairment of correct performance. Rats treated with olanzapine and clozapine presented a decrease in motor activity level at the same time. After the test at acute dosage, rats were chronically treated for 14 days with olanzapine, clozapine or scopolamine and 24 h after the last dose were again tested in the 8-arm radial maze. Under this procedure, chronic treatment with olanzapine, clozapine and scopolamine did not impair correct task performance and did not modify distance travelled. We concluded that the sedative effect masked a possible effect on working memory after acute administration of olanzapine and clozapine, whereas chronic treatment with olanzapine, clozapine and scopolamine did not adversely affect working memory performance. In the case of scopolamine, it suggests that chronic muscarinic antagonism does not induce memory impairment and for atypical antipsychotics, it suggests that chronic treatment induced a tolerance to acute motor effects of these drugs.

Tramadol, (1RS,2RS)-2-[(dimethylamine)-methyl]-1-(3-methoxyphenyl)-cyclohexanol hydrochloride, is an atypical centrally acting analgesic agent with relatively weak opioid receptor affinity and which, like some antidepressants, is able to inhibit the reuptake of serotonin (5-hydroxytryptamine, 5-HT) in the raphe nucleus. We have previously demonstrated that pindolol, a beta-adrenoceptor blocker/5-hydroxytryptamine(1A/1B) receptor antagonist, enhanced tramadol antinociception and that the selective 5-HT1A agonist 8-Hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT) reduced it. These effects were related to the negative feedback control that regulates raphe region neurones. The current study examines the ability of the selective antagonist at somatodendritic 5-HT1A receptors, N-[2-[4-(2-methoxyphenyl)-1-piperazinyl] ethyl]-N-(2-pyridinyl) cyclohexane carboxamide (WAY100635, 0.8 mg/kg), the selective antagonist at terminal 5-HT1B receptors, N-[3-(2-dimethylamino) ethoxy-4-methoxyphenyl]-2'-methyl-4'-(5-methyl-1,2,4-oxadiazol-3-yl)-(1,1'-biphenyl)-4-carboxamide (SB216641, 0.1-0.8 mg/kg) and the selective agonist at 5-HT1B receptors, 1,4-tDihydro-3-(1,2,3,6-tetrahydro-4-pyridinyl)-5H-pyrrolo[3,2-b] pyridin-5-one (CP93129, 0.2-0.4 mg/kg), to modify the antinociceptive effect of 4-64 mg/kg of tramadol in the hot plate test in mice. The results show that 0.8 mg/kg of WAY100635 enhanced antinociceptive effect of tramadol while neither agonism nor antagonism at the 5-HT1B receptor modifies it significantly at the doses tested. These results account for involvement of the somatodendritic 5-HT1A receptors in the analgesic effect of tramadol and support the supraspinal interaction of serotonin and the opioid system in the regulation of pain.

Rationale: The principal use of antidepressants is in the treatment of depression and affective disorders. Antidepressants have also been used as an adjuvant to analgesics in pain treatment. However, in chronic treatment, their antinociceptive and antidepressive effects coexist simultaneously. Antidepressants can interact with the opioid system, which is also involved in regulating nociceptive processing and affective state. Chronic antidepressants could act by increasing mu-opioid receptor expression in many brain areas involved in the regulation of nociception and affective state., Objectives: The aim of this study was to evaluate the antinociceptive and antidepressant-like effects and the possible variations in mu-opioid receptor expression induced by a chronic nefazodone treatment in brain areas related to pain and affective state., Methods: Wistar rats were chronically treated with nefazodone (10 and 25 mg/kg IP, twice a day, for 14 days). Twelve hours after the last day 14 dose of nefazodone, a tail-flick test was performed. After the administration of a daily dose of nefazodone, Porsolt's test was carried out 12 h after last dose. Two hours after completion of 14 days treatment, other animals were processed for mu-opioid receptor immunocytochemistry using polyclonal antisera raised in rabbits. Several brain regions were analyzed: the frontal and cingulate cortex, the dorsal raphe nucleus and the periaqueductal gray., Results: Chronic nefazodone treatment induced a significant increase in tail-flick latency and a significant decrease in immobility time at total doses of 20 and 50 mg/kg per day ( P<0.05). In treated animals, the density of neural cells immunostained for mu-opioid receptor in the frontal and cingulate cortices, dorsal raphe nucleus and periaqueductal gray had increased after chronic nefazodone compared to controls., Conclusion: Therefore, chronic nefazodone induces antinociceptive and antidepressant-like effects in rats and increases mu-opioid receptor expression in brain areas related to pain and affective state. These results suggest that antidepressants could be effective on somatic and affective dimensions of pain and this action could be related to its influence on the opioid system.

Tramadol is a centrally acting analgesic that demonstrates opioid and monoaminergic properties. Several studies have suggested that tramadol could play a role in mood improvement. Moreover, it has previously been shown that tramadol is effective in the forced swimming test in mice and the learned helplessness model in rats, two behavioural models predictive of antidepressant activity. The aim of the present study was to test tramadol and its enantiomers in the reserpine test in mice, a classical observational test widely used in the screening of antidepressant drugs. This test is a non-behavioural method where only objective parameters such as rectal temperature and palprebral ptosis are considered. Moreover, we compared the effects of tramadol and its enantiomers with those of antidepressants (desipramine, fluvoxamine and venlafaxine) and opiates [morphine (-)-methadone and levorphanol]. Racemic tramadol, (-)-tramadol, desipramine and venlafaxine reversed the reserpine syndrome (rectal temperature and ptosis), whereas(+)-tramadol and fluvoxamine only antagonized the reserpine-induced ptosis, without any effect on temperature. Opiates did not reverse reserpine-induced hypothermia. (-)-Methadone showed slight effects regarding reserpine-induced ptosis, morphine and levorphanol had no effect. These results show that tramadol has an effect comparable to clinically effective antidepressants in a test predictive of antidepressant activity, without behavioural implications. Together with other clinical and experimental data, this suggests that tramadol has an inherent antidepressant-like (mood improving) activity, and that this effect could have clinical repercussions on the affective component of pain.

The opioid system has been implicated in mood disorders as well as in the mechanism of action of antidepressants. Since the opioid component in venlafaxine (VLX) is still a matter of discussion, we investigated the role of opioid receptors in the antidepressant-like effect of VLX in the forced swimming test in mice. The non-selective opiate antagonist naloxone at high dose (2 mg/kg, s.c.) antagonized the effect of VLX. In contrast, beta-funaltrexamine (40 mg/kg, s.c.), which preferentially blocks mu(1)/mu(2) opioid receptors, naloxonazine (35 mg/kg, s.c.), a selective mu(1) opioid antagonist, naltrindole (10 mg/kg, s.c.), a selective delta opioid antagonist, and Nor-binaltorphimine (10 mg/kg, s.c.), which selectively blocks kappa-opioid receptors, were all ineffective. Thus, although apparently mediated by the opioid system, the behavioural effect of VLX does not involve specific opioid receptors.

Objective: The likelihood of developing psychotic symptoms greatly increases after puberty. In acute psychotic disorders, first rank symptoms (FRS) are prevalent and considered useful for the diagnostic process. The aim of this study was to test for a linear association between age and the probability of occurrence of FRS in patients with a first psychotic episode (FPE)., Method: A total of 112 patients, consecutively admitted with an FPE, were included at baseline and evaluated yearly over a 3-year period using SCID-I and a checklist of 11 items of FRS., Results: FRS were documented for 65.2% patients at baseline. There was a dose-response relationship in the association between age and FRS. There was no interaction with sex or with final diagnostic category., Conclusion: Variation in the expression of the core positive symptoms of psychosis is subject to the influence of underlying age-dependent maturational processes both in terms of occurrence and level of severity.

This study was undertaken to investigate the effects induced by chronic systemic administration of two different antidepressants: imipramine (IMI), a dual serotonin-noradrenaline reuptake inhibitor, and fluvoxamine (FVX), a selective serotonin reuptake inhibitor, on the antinociceptive effect of morphine (MOR) in a paw pressure test in adjuvant-induced arthritic rats. For 30 days rats were administered with IMI, FVX or saline (SAL). On days 15 and 30, animals were tested in the paw pressure test 20 min after MOR or SAL administration. MOR induced a significant antinociceptive effect in IMI, FVX and SAL treated rats. But, at 30 days, this increase in pain threshold was significatively higher in IMI than SAL rats. This increase was not seen in FVX rats. These results suggest that a combination of opioid and mixed monoaminergic activities is effective in enhancing the antinociceptive effect of MOR in arthritic rats while only opioid and serotonergic activities have no enhancer effect.

This study evaluates the antinociceptive effect of several tricyclic antidepressants in four nociceptive tests which employ either thermal (hot plate and tail flick tests) or chemical (formalin and acetic acid tests) stimuli. Forced swimming test was also performed as a model of depression and an activity test was also performed. Mixed antidepressants in current clinical use: amitriptyline, imipramine and clorimipramine and their respective main secondary metabolites which preferentially inhibit noradrenaline reuptake: nortriptyline, desipramine and desmethylclorimipramine, were tested (2.5-20 mg/kg, i.p.) in mice. The results show a stronger antinociceptive effect in chemical tests induced by all the drugs, compared with thermal tests. The doses needed to produce antinociception were lower than those inducing an antidepressive effect, both effects being mutually independent. The overall results show that preferentially noradrenergic tricyclics induced an antinociceptive effect comparable with that of mixed tricyclics, indicating that noradrenaline reuptake plays an important role in tricyclic-induced antinociception.

Psychotic symptoms frequently occur in bipolar disorder, especially in younger patients. However, whether the association with younger age also extends to psychotic symptoms that have traditionally been associated with schizophrenia, such as Schneiderian first-rank symptoms (FRSs), is unclear. This study examined FRSs in bipolar I patients and their relationship to age and gender. The sample comprised 103 consecutive inpatients who met DSM IV criteria for bipolar disorder, manic or mixed. FRSs were rated with the Scale for the Assessment of Positive Symptoms (SAPS). Interaction between FRSs and gender and FRSs and age was assessed using logistic regression. A high rate of FRSs in manic and mixed patients was found with a higher frequency in men (31%) than in women (14%; P=0.038). A monotonic increase in the association between FRSs and younger age was apparent (odds ratios (OR) over five levels: 1.42; 1.00-2.01). These results confirm previous findings that FRSs are not specific to schizophrenia and suggest in addition that a dimension of nuclear psychotic experiences of developmental origin extends across categorically defined psychotic disorders.

Background: It has been proposed that serotonin participates in the central antinociceptive effect of acetaminophen. The serotonin activity in the brainstem is primarily under the control of 5-HT1A somatodendritic receptors, although some data also suggest the involvement of 5-HT1B receptors. In the presence of serotonin, the blockade of 5-HT(1A/B) receptors at the level of the raphe nuclei leads to an increase in serotonin release in terminal areas, thus improving serotonin functions. This study examines the involvement of 5-HT(1A/B) receptors in the antinociceptive effect of acetaminophen in mice., Methods: The effects of acetaminophen (600 mg/kg intraperitoneal) followed by different doses of antagonists (WAY 100635 [0.2-0.8 mg/kg subcutaneous] and SB 216641 [0.2-0.8 mg/kg subcutaneous]) or agonists (8-OH-DPAT [0.25-1 mg/kg subcutaneous] and CP 93129 [0.125-0.5 mg/kg subcutaneous]) of 5-HT1A and 5-HT1B receptors, respectively, were determined in the hot-plate test in mice., Results: Acetaminophen (300-800 mg/kg) showed a dose-dependent antinociceptive effect in the hot-plate test in mice. WAY 100635 (0.2-0.8 mg/kg; 5-HT1A antagonist) induced an increase in the antinociceptive effect of 600 mg/kg acetaminophen, but this increase was not dose related. Conversely, 8-OH-DPAT (0.25-1 mg/kg; 5-HT1A agonist) decreased the antinociceptive effect of acetaminophen. SB 216641 (0.2-0.8 mg/kg; 5-HT1B antagonist) induced a dose-related increase in the antinociceptive effect of acetaminophen, and CP 93129 (0.25 mg/kg; 5-HT1B agonist) significantly decreased the antinociceptive effect of acetaminophen., Conclusions: These results suggest that the combination of acetaminophen with compounds having 5-HT1A and 5-HT1B antagonist properties could be a new strategy to improve the analgesia of acetaminophen, thanks to its mild serotonergic properties.

Affective states are regulated mainly by serotonin and noradrenaline. However the opioid system has been also related to antidepressant-induced mood improvement, and the mu-opioid receptor has been involved in affective responses to a sustained painful stimulus. Similarly, antidepressant drugs induce an antinociceptive effect via both the monoaminergic and opioid systems, probably involving sensorial and affective dimensions of pain. The aim of this study was to test three opiate analgesics, which also inhibit monoamine reuptake, in the learned helplessness model of depression in rats. Helpless rats receiving (+/-)tramadol (10, 20 mg/Kg) or (-)methadone (2, 4 mg/Kg) showed a decreased number of failures to avoid or escape aversive stimulus (shock) in both the second and the third daily sessions, compared with controls. Rats receiving levorphanol (0.5, 1 mg/Kg) showed a decreased number of such failures in the third session. The number of crossings in the intertrial interval (ITI) was not significantly modified by (+/-)tramadol or (-)methadone. Levorphanol enhanced ITI crosses at 1 mg/Kg. These results, together with other clinical and experimental data, suggest that analgesics with monoaminergic properties improve mood and that this effect may account for their analgesic effect in regulating the affective dimension of pain. From this, it seems probable that the analgesic effect of opiates could be induced by adding together the attenuation produced of both the sensorial and the affective dimensions of pain.