Pain perception in schizophrenia: influence of neuropeptides, cognitive disorders, and negative symptoms

Sex-specific differences in the clinical profile among psychiatric patients with pulmonary Embolism: a hospital-based retrospective study

BACKGROUND

Pulmonary embolism (PE) is a severe and life-threatening complication of venous thromboembolism. However, there is a lack of systematic studies on differences between female and male PE patients. This paper aimed to compare the sex-specific differences in clinical characteristics and laboratory indicators in psychotic patients with PE.

METHODS

This retrospective study enrolled psychiatric patients with PE from June 2018 to June 2022 at Shenzhen Kangning Hospital (Shenzhen Mental Health Center). Demographic characteristics, factors associated with PE, and laboratory indices were collected to assess sex-specific differences.

RESULTS

Of the 168 patients, 87 (51.8%) were female and 81 (48.2%) were male, with a mean age of 58 years for females and 46 years for male patients. The male group had higher ratio of hyperprolactinemia, more patients using antipsychotic medications, higher D-dimer levels at PE onset, greater D-dimer difference, and a higher rate of D-dimer elevation than the female group (p < 0.05). Female patients were significantly older, exhibited a higher prevalence of diabetes, and had a greater number of patients taking antidepressants and hypnotics/sedatives than male patients (p < 0.05). Schizophrenia spectrum disorders were more prevalent in male patients, while female patients had a higher incidence of mood disorders (p < 0.05). Among patients aged < 45 years, the male group had higher D-dimer levels at PE onset and greater D-dimer difference (p < 0.05). Among all 112 patients aged ≥ 45 years, male patients were more likely than female patients to have respiratory tract infections, higher D-dimer levels at PE onset, greater D-dimer difference, and a higher rate of D-dimer elevation (p < 0.05). The multiple linear regression analysis indicated that hyperprolactinemia and the use of first-generation antipsychotics (FGAs) were associated with D-dimer levels at PE onset in male patients, while the time of PE onset and protective restraints were associated with D-dimer levels at PE onset in female patients (p < 0.05).

CONCLUSION

PE-associated clinical features differ between male and female patients. These differences may imply that the processes and mechanisms of PE onset are sex specific. Male patients are more likely to have respiratory tract infections and higher D-dimer levels at PE onset than female patients. The use of FGAs may be associated with increased D-dimer in male psychiatric patients, while protective restraints may be associated with increased D-dimer in female psychiatric patients.

Nationwide Assessment of Chronic Pain among Hospitalized Individuals with Co-occurring Post Traumatic Stress Disorder and Substance Use Disorder in the United States

Objective: Chronic pain (CP) is independently associated with substance use disorders (SUD) and posttraumatic stress disorder (PTSD). However, little is known about factors associated with CP among patients with co-occurring PTSD and SUD. Patterns of hospital resource usage should also be explored further. Methods: Using the 2019 National Inpatient Sample (NIS), we identified 216,125 hospital discharges with co-occurring diagnoses of PTSD and SUD in 2019 and examined their association with CP. Multivariable logistic regression models were used to identify factors associated with an increased likelihood of CP in this cohort. Results: Among those with co-occurring PTSD and SUD (N = 216,125), 35,450 had associated CP, a prevalence of 164.02 cases per 1,000 discharges (95% CI [160.54, 167.52]). Individuals aged 55-64 with co-occurring PTSD and SUD were approximately 7.2 times more likely to experience CP, compared to those aged 16-24 (OR = 7.2; 95% CI [6.09, 8.60]). Being in the CP group was associated with 50% increased odds of insomnia and obesity (OR = 1.5; 95% CI [1.12, 2.03] and OR = 1.5; 95% CI [1.38, 1.55], respectively), 30% increased odds of anxiety (OR = 1.3; 95% CI [1.24, 1.38]), 20% increased odds of attention deficit disorder (ADD;OR = 1.2; 95% CI [1.12, 1.38]) and 10% increased odds of depression (OR = 1.1; 95% CI [1.01, 1.14]). Compared with females, being male was associated with slightly decreased odds of CP (OR = 0.9; 95% CI [0.84, 0.94]). Conclusions: Among hospitalized Americans with co-occurring PTSD and SUD, advanced age, being female, and the presence other mental health disorders were associated with an increased risk of CP. Providers treating co-occurring PTSD/SUD should evaluate for and consider evidence-based management of CP if present.

Prescription opioid dispensing patterns among patients with schizophrenia or bipolar disorder

BACKGROUND

Patients with schizophrenia (SZ) or bipolar disorder (BD) may have increased risk of complications from prescribed opioids, including opioid-induced respiratory depression. We compared prescription opioid pain medication dispensing for patients with SZ or BD versus controls over 5 years to assess dispensing trends.

METHODS

This retrospective, observational study analysed US claims data from the IBM® MarketScan® Commercial and Multi-State Medicaid databases for individuals aged 18-64 years with prevalent SZ or BD for years 2015-2019 compared with age- and sex-matched controls. Baseline characteristics, comorbidities, and medication use were assessed. Proportions of individuals dispensed prescription opioids chronically (ie, ≥70 days over a 90-day period or ≥ 6 prescriptions annually) or nonchronically (≥1 prescription, chronic definition not met) were assessed.

RESULTS

In 2019, the Commercial and Medicaid databases contained records for 4773 and 30,179 patients with SZ and 52,780 and 63,455 patients with BD, respectively. Patients with SZ or BD had a higher prevalence of comorbidities, including pain, versus controls in each analysis year. From 2015 to 2019, among commercially insured patients with SZ, chronic opioid-dispensing proportions decreased from 6.1% (controls: 2.7%) to 2.3% (controls: 1.2%) and, for patients with BD, from 11.4% (controls: 2.7%) to 6.4% (controls: 1.6%). Chronic opioid dispensing declined in Medicaid-covered patients with SZ from 15.0% (controls: 14.7%) to 6.7% (controls: 6.0%) and, for patients with BD, from 27.4% (controls: 12.0%) to 12.4% (controls: 4.7%). Among commercially insured patients with SZ, nonchronic opioid dispensing decreased from 15.5% (controls: 16.4%) to 10.7% (controls: 11.0%) and, for patients with BD, from 26.1% (controls: 17.5%) to 20.0% (controls: 12.2%). In Medicaid-covered patients with SZ, nonchronic opioid dispensing declined from 22.5% (controls: 24.4%) to 15.1% (controls: 12.7%) and, for patients with BD, from 32.3% (controls: 25.9%) to 24.6% (controls: 13.6%).

CONCLUSIONS

The proportions of individuals dispensed chronic or nonchronic opioid medications each year were similar between commercially and Medicaid-insured patients with SZ versus controls and were higher for patients with BD versus controls. From 2015 to 2019, the proportions of individuals who were dispensed prescription opioids chronically or nonchronically decreased for patients with SZ or BD and controls.

From periphery immunity to central domain through clinical interview as a new insight on schizophrenia

Identifying disease predictors through advanced statistical models enables the discovery of treatment targets for schizophrenia. In this study, a multifaceted clinical and laboratory analysis was conducted, incorporating magnetic resonance spectroscopy with immunology markers, psychiatric scores, and biochemical data, on a cohort of 45 patients diagnosed with schizophrenia and 51 healthy controls. The aim was to delineate predictive markers for diagnosing schizophrenia. A logistic regression model was used, as utilized to analyze the impact of multivariate variables on the prevalence of schizophrenia. Utilization of a stepwise algorithm yielded a final model, optimized using Akaike's information criterion and a logit link function, which incorporated eight predictors (White Blood Cells, Reactive Lymphocytes, Red Blood Cells, Glucose, Insulin, Beck Depression score, Brain Taurine, Creatine and Phosphocreatine concentration). No single factor can reliably differentiate between healthy patients and those with schizophrenia. Therefore, it is valuable to simultaneously consider the values of multiple factors and classify patients using a multivariate model.

Alterations of serum neuropeptide levels and their relationship to cognitive impairment and psychopathology in male patients with chronic schizophrenia

Serum neuropeptide levels may be linked to schizophrenia (SCZ) pathogenesis. This study aims to examine the relation between five serum neuropeptide levels and the cognition of patients with treatment-resistant schizophrenia (TRS), chronic stable schizophrenia (CSS), and in healthy controls (HC). Three groups were assessed: 29 TRS and 48 CSS patients who were hospitalized in regional psychiatric hospitals, and 53 HC. After the above participants were enrolled, we examined the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) and the blood serum levels of α-melanocyte stimulating hormone (α-MSH), β-endorphin (BE), neurotensin (NT), oxytocin (OT) and substance.P (S.P). Psychiatric symptoms in patients with SCZ were assessed with the Positive and Negative Syndrome Scale. SCZ patients performed worse than HC in total score and all subscales of the RBANS. The levels of the above five serum neuropeptides were significantly higher in SCZ than in HC. The levels of OT and S.P were significantly higher in CSS than in TRS patients. The α-MSH levels in TRS patients were significantly and negatively correlated with the language scores of RBANS. However, the BE and NT levels in CSS patients were significantly and positively correlated with the visuospatial/constructional scores of RBANS. Moreover, the interaction effect of NT and BE levels was positively associated with the visuospatial/constructional scores of RBANS. Therefore, abnormally increased serum neuropeptide levels may be associated with the physiology of SCZ, and may cause cognitive impairment and psychiatric symptoms, especially in patients with TRS.

Migraine in bipolar disorder and schizophrenia: The hidden pain

OBJECTIVE

This study examined the prevalence of comorbid migraine in patients with bipolar disorder and those with schizophrenia and also examined the association between migraine comorbidity and disease characteristics in both disorders.

METHODS

In this cross-sectional study, 150 patients with bipolar disorder and 150 with schizophrenia were evaluated for migraine diagnosis using the International Classification of Headache Disorders (3rd ed). Patients were selected from psychiatry outpatient clinics at Kasr Al Ainy hospitals, Cairo University.  The Young Mania Rating Scale (YMRS) and the Hamilton Depression Rating Scale (HDRS) were administered to the bipolar group, whereas the Positive and Negative Syndrome Scale (PANSS) was administered to the schizophrenia group. Both groups were evaluated by the Clinical Global Impressions (CGI) scale.

RESULTS

The diagnosis of migraine was made in 34 (22.7%) of the bipolar group and 24 (16.0%) of the schizophrenia group. Patients with schizophrenia showed a significantly higher frequency and intensity of migraine attacks on the Migraine Disability Assessment scale than did the bipolar group (p < 0.001). In the bipolar group, there was no significant difference between patients with and without migraine on the YMRS, HDRS, and CGI. Among patients with schizophrenia, the duration of the migraine attacks was positively correlated with CGI scores (r = 0.40, p = 0.02).

CONCLUSION

Migraine was found to be a significant comorbidity in patients with bipolar disorder and schizophrenia. However, the intensity and frequency of migraine attacks were higher in the schizophrenia than in the bipolar group.

Plasma neuropeptide levels in patients with schizophrenia, bipolar disorder, or major depressive disorder and healthy controls: A multiplex immunoassay study

AIM

We aimed to compare neuropeptide levels between patients with major psychiatric disorders and healthy controls and examine their association with symptoms and cognitive function.

METHODS

The participants were 149 patients with schizophrenia, 115 patients with bipolar disorder (BD), 186 unremitted patients with major depressive disorder (MDD), and 350 healthy controls. Psychiatric (schizophrenic, manic, and depressive) symptoms, sleep state, and cognitive (premorbid intelligence quotient, general cognitive, and memory) functions were evaluated. A multiplex immunoassay kit was used to measure cerebrospinal fluid (CSF) and plasma α-melanocyte-stimulating hormone (MSH), β-endorphin, neurotensin, oxytocin, and substance P levels.

RESULTS

The verification assay revealed that CSF α-MSH, β-endorphin, neurotensin, oxytocin, and substance P levels were too low to be reliably measured, while plasma α-MSH, β-endorphin, neurotensin, oxytocin, and substance P levels could be successfully measured. Plasma α-MSH, β-endorphin, neurotensin, oxytocin, and substance P levels were not significantly different between patients with schizophrenia, BD, or MDD and healthy controls. Plasma α-MSH, β-endorphin, neurotensin, oxytocin, and substance P levels were not significantly correlated with psychiatric symptom scores in patients with schizophrenia, BD, or MDD and cognitive function scores in patients or healthy controls.

CONCLUSION

Our data suggest that plasma neuropeptide levels do not elucidate the involvement of neuropeptides in the pathology of schizophrenia, BD, or MDD.

Risks of complicated acute appendicitis in patients with psychiatric disorders

BACKGROUND

Acute appendicitis often presents with vague abdominal pain, which fosters diagnostic challenges to clinicians regarding early detection and proper intervention. This is even more problematic with individuals with severe psychiatric disorders who have reduced sensitivity to pain due to long-term or excessive medication use or disturbed bodily sensation perceptions. This study aimed to determine whether psychiatric disorder, psychotropic prescription, and treatment compliance increase the risks of complicated acute appendicitis.

METHODS

The diagnosis records of acute appendicitis from four university hospitals in Korea were investigated from 2002 to 2020. A total of 47,500 acute appendicitis-affected participants were divided into groups with complicated and uncomplicated appendicitis to determine whether any of the groups had more cases of psychiatric disorder diagnoses. Further, the ratio of complicated compared to uncomplicated appendicitis in the mentally ill group was calculated regarding psychotropic dose, prescription duration, and treatment compliance.

RESULTS

After adjusting for age and sex, presence of psychotic disorder (odds ratio [OR]: 1.951; 95% confidence interval [CI]: 1.218-3.125), and bipolar disorder (OR: 2.323; 95% CI: 1.194-4.520) was associated with a higher risk of having complicated appendicitis compared with absence of psychiatric disorders. Patients who are taking high-daily-dose antipsychotics, regardless of prescription duration, show high complicated appendicitis risks; High-dose antipsychotics for < 1 year (OR: 1.896, 95% CI: 1.077-3.338), high-dose antipsychotics for 1-5 years (OR: 1.930, 95% CI: 1.144-3.256). Poor psychiatric outpatient compliance was associated with a high risk of complicated appendicitis (OR: 1.664, 95% CI: 1.014-2.732).

CONCLUSIONS

This study revealed a close relationship in the possibility of complicated appendicitis in patients with severe psychiatric disorders, including psychotic and bipolar disorders. The effect on complicated appendicitis was more remarkable by the psychiatric disease entity itself than by psychotropic prescription patterns. Good treatment compliance and regular visit may reduce the morbidity of complicated appendicitis in patients with psychiatric disorders.

Higher amoebic and metronidazole resistant forms of Blastocystis sp. seen in schizophrenic patients

Background

Blastocystis sp. is one of the most common colonisers of the intestinal tract that demonstrate strong interaction with accompanying gut bacteria. Previously, the protozoan isolated from individuals with irritable bowel syndrome (IBS) showed altered phenotypic features suggesting that it can be triggered to become pathogenic. Previous studies reported altered gut microbiota and high prevalence of Blastocystis sp. in schizophrenia patients. However, the phenotypic characteristics of Blastocystis sp. isolated from individuals with SZ have yet to be described.

Methods

In this study, faecal samples from 50 patients with severe schizophrenia (SZ) and 100 non-schizophrenic (NS) individuals were screened for Blastocystis sp. infection. Positive isolates were subjected to genotypic and phenotypic characterization.

Results

We found that 12 out of 50 (24%) SZ and 5 out of 100 (5%) NS individuals were detected Blastocystis sp. positive using both in vitro culture and PCR method with no significant association to age and gender. Out of the 15 sequenced isolates, ST3 was the most prevalent subtype (66.7%) followed by ST1 (20%) and ST6 (13.3%). The isolates from SZ individuals demonstrated significant slower growth rate (34.9 ± 15.6 h) and larger range of cell diameter (3.3–140 µm). We detected higher amoebic forms and metronidazole resistance among SZ isolates with variation in cell surface glycoprotein where 98% of cells from SZ showed consistent medium to high binding affinity (+ 2 to + 3) to Concavalin A staining compared to NS isolates that demonstrated only 76% high lectin (+ 3) binding affinity. Cysteine and serine protease levels were predominantly found among SZ isolates. We also demonstrate the presence of metalloprotease in Blastocystis sp. especially among NS isolates. Introduction of solubilised antigens from SZ isolates increased the cell proliferation of HCT116 cells by two fold when compared to NS isolates.

Conclusion

Our findings demonstrated Blastocystis sp. isolated from SZ individuals showed variation in phenotype specifically in morphology and drug resistance. The findings indicate that the gut environment (SZ and NS) and treatment of SZ could have influenced the phenotype of Blastocystis sp.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13071-022-05418-0.

Chronic Pain: Among Tertiary Care Psychiatric Out-Patients in Singapore—Prevalence and Associations with Psychiatric Disorders

Objective

The study aimed to determine the prevalence and severity of chronic pain and its associations amongst psychiatric out-patients in a tertiary care hospital in Singapore. Methodology. The cross-sectional study was conducted among 290 psychiatric out-patients aged 21–65 years. Sociodemographic and clinical information, as well as data from Brief Pain Inventory-Short Form (BPI-sf), Beck's Depression Inventory II (BDI-II), and Beck's Anxiety Inventory (BAI) were collected. Cut points (C.P.s) dividing the sample into mild, moderate, and severe groups were created for the ratings of average pain. Eight possible cut-off values for the C.P.s between 3 and 7, representing 8 different categorical variables, were created and their relationships were examined with BPI's set of seven interference items using multivariate analysis of variance. Sociodemographic and clinical correlates of chronic pain were determined using multinomial logistic regression analysis. Analysis of covariance was used to determine the association of BPI with continuous scores of BAI and BDI.

Results

Based on the C.P. pain severity classification, 38.5% of the sample had mild pain, 22.9% had moderate pain, and 11.8% had severe pain. Patients with severe pain were more likely to be associated with older age (p ≤ 0.006) (versus young age), less likely to be married (p ≤ 0.025) (versus single), and more likely to have high risk for obesity (p ≤ 0.030) (versus low risk for obesity). Participants with mild pain were seen to be significantly associated with older age (p ≤ 0.021), whereas moderate pain (p ≤ 0.002) and severe pain (p ≤ 0.001) (versus no pain) were seen to be significantly associated with higher BAI scores.

Conclusion

The current study observed high prevalence of pain among patients with psychiatric illness that was determined by optimal C.P.s for mild, moderate, and severe pain. Patients diagnosed with anxiety disorders and those with higher BMI were seen to be associated with pain of moderate to severe intensity. Improving the knowledge of correlates and co-morbidities of physical pain would aid in early identification, use of prophylactic strategies, and the intervention techniques to formulate basic guidelines for pain management among psychiatric population.

Altered physical pain processing in different psychiatric conditions

Several reports indicate either increased or decreased pain sensitivity associated with psychiatric disorders. Chronic pain is highly prevalent in many of these conditions. We reviewed the literature regarding experimental pain sensitivity in patients with major depression, bipolar disorder, posttraumatic stress disorder (PTSD), generalized anxiety disorder, panic disorder, obsessive-compulsive disorder and schizophrenia. Electronic searches were performed to identify studies comparing experimental pain in patients with these conditions and controls. Across 31 depression studies, reduced pain threshold was noted except for ischemic stimuli, where increased pain tolerance and elevated sensitivity to ischemic pain was observed. A more pervasive pattern of low pain sensitivity was found across 20 schizophrenia studies. The majority of PTSD studies (n = 20) showed no significant differences compared with controls. The limited number of bipolar disorder (n = 4) and anxiety (n = 9) studies precluded identification of clear trends. Wide data variability was observed. Awareness of psychiatric patients' pain perception abnormalities is needed for active screening and addressing physical comorbidities, in order to enhance quality of life, life expectancy and mental health.

Atraumatic Bilateral Acute Compartment Syndrome of the Lower Legs: A Review of the Literature

Bilateral acute compartment syndrome of the legs is a very rare presentation that requires emergency surgical intervention. Atraumatic bilateral cases are almost unheard of in medicine. There is currently no link between compartment syndrome and cognitive impairment or mental health.

A systematic literature search was performed in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines using the following keywords in multiple databases: compartment syndrome, atraumatic, spontaneous, bilateral, both, lower leg, acute, compartmental pressure, and fasciotomy. Atraumatic, bilateral, acute, and confirmed compartment syndrome cases were included.

In total, 33 cases of atraumatic bilateral acute compartment syndrome (ABACS) were identified, of those 72.7% of cases were males. A form of cognitive impairment was found in 66% of cases. The medical history of the cases included substance abuse (nine patients), mental health illness (seven patients), and hypothyroidism (four patients). Within the reports, there was evidence of a misdiagnosis or delayed management in 19 cases (57.6%). Creatinine kinase (CK) was measured in 28 cases with a mean CK of 110,893 IU/L. Compartment pressure measurements were used in only 12 cases. A total of 29 cases were managed with bilateral four-compartment fasciotomy.

This review highlights that ABACS is a condition with high rates of misdiagnosis or delay in treatment. Associations found included patients with cognitive impairment on presentation, mental health conditions, substance misuse, and elevated levels of CK. In addition, this review demonstrates that this condition is less rare than previously thought with serious morbidity and mortality.

Evaluation of acute and chronic nociception in subchronically administered MK-801-induced rat model of schizophrenia

Patients diagnosed with schizophrenia have been reported to exhibit atypically low pain sensitivity and to vary in their experience of chronic pain. To the best of our knowledge, there has yet to be an animal study that provides information concerning the relationship between models of schizophrenia and pain. In the present study, we investigated several distinct nociceptive behaviors in a translational rat model of schizophrenia (0. 5 mg/kg MK-801, twice a day for 7 days followed by a 7-day washout period). The presence of the expected cognitive deficit was confirmed with novel object recognition (NOR) paradigm prior to nociception testing. MK-801-treated rats with lack of novelty interest in NOR testing showed: hyposensitivity to thermal and mechanical stimuli; short-term hypoalgesia followed by augmented hyperalgesia in response to formalin-induced spontaneous nociception and increased thermal and mechanical hyperalgesia in the complete Freund's adjuvant (CFA) induced chronic pain model. In conclusion, MK-801 induced antinociception effects for thermal stimuli in rats that were consistent with the decreased pain sensitivity observed in schizophrenia patients. Additionally, the amplified biphasic response exhibited by the MK-801 group in the formalin-induced spontaneous nociception test affirms the suitability of the test as a model of acute to delayed pain transition.

Guanosine ameliorates positive symptoms of schizophrenia via modulating 5-HT1A and 5-HT2A receptors

Schizophrenia is a serious mental disorder characterized by hallucinations, delusions, and extremely disordered thinking and behavior. There are several hypotheses of pathogenesis in schizophrenia: dopaminergic, glutamatergic, or serotonergic hyperfunction. Guanosine reportedly protects the central nervous system by modulating the glutamatergic system. Thus, we assumed that guanosine may exert a positive effect on the pathophysiology of schizophrenia. Herein, we demonstrated that guanosine significantly reduced MK-801-induced hyperlocomotion and stereotyped behaviors, but showed no effect on hyperlocomotion induced by d-amphetamine, indicating that guanosine may directly affect the glutamatergic system. Guanosine dose-dependently reduced 5-HTP-induced wet dog shakes (WDS) and other serotonin syndromes (SS) behaviors, indicating that it might block serotonin 5-HT_1A or 5-HT_2A receptors. Finally, we confirm that that guanosine modulates serotonin 5-HT_1A and 5-HT_2A receptors and it might be anti-schizophrenic partly through pertussis toxin-sensitive G_i/o-coupled PI3K/Akt signaling. Collectively, this study provides possible compounds and mechanisms for therapeutic effects on schizophrenia.

Reduced pain perception in patients with schizophrenia; A missed case of hand fracture

Altered pain perception among patients with schizophrenia is often underrecognized in the medical community. The cause is not known, and medical professionals are not sure whether these patients experience less pain or are simply unable to express it. There are documented cases of patients with schizophrenia presenting to hospital settings with serious injuries without obvious (expected) pain. Research into the underlying cause(s) is underway; meanwhile, ensuring awareness of this issue among medical providers is of upmost importance. We report a case of a patient with schizophrenia who presented voluntarily to the emergency department (ED) with a hand fracture that went unrecognized in the ED and further discuss the implications of reduced pain perception. Additionally, we summarize existing hypotheses regarding the source of this reduced pain perception in this population.

A qualitative study on experiences of persons with schizophrenia in oral-health-related quality of life

Our study aimed to explore the views and experiences in oral health and oral-health-related quality of life (OHRQoL) of persons with schizophrenia (PWS) in order to expand the understanding of the factors that either limit or facilitate their healthcare pathway, which can ultimately optimize their oral health and/or OHRQoL. A qualitative study was conducted in France in the Côte d'Or department (530 000 in habitants) centered on PWS's perceived meanings regarding oral health or OHRQoL, and semi-structured individual interviews were used. A conventional content analysis approach was chosen in order to highlight unrevealed themes. A sample of 20 PWS (12 males; 8 females) with a median age was 45.8 (± 9.5) were recruited to assess views and experiences regarding OHRQoL, which were focused on three dimensions: an individual dimension related to experience of "oral symptoms", a second dimension related to experience of "stress and its management", and a third related to "Autonomy dimension in oral health". We showed that PWS clearly expressed their mental representations of oral health and OHRQoL. This study supports that PWS were able to define their needs and had the ability to discuss their oral health and OHRQoL. These finding could be used to support specific interventions for this population to better manage the negative impact of antipsychotics and help them to consult dentists on a regular basis.

Pain Sensitivity in Schizophrenia Spectrum Disorders: A Narrative Review of Recent Work

Many patients with schizophrenia seem relatively immune to physical pain while others complain of constant pain. This may result from disturbances or alterations of the sensory threshold for pain in populations with psychosis, a possibility for which there is some preliminary evidence. The inconsistency in pain perception may, in part, be explained by the treatments patients receive, but treatment-naïve patients also exhibit differences in response to pain. This suggests that decreased pain sensitivity may represent a specific psychosis endophenotype. Thus far, few experimental studies have investigated sensory thresholds, pain modalities, or other factors contributing to the perception or expression of physical pain in psychosis. A digital search for information on this topic was conducted in PubMed and Google Scholar. The result is a non-systematic, narrative review focusing on recent clinical and experimental findings of pain sensitivity in patients with psychosis. Importantly, physical and mental pain are closely connected constructs that may be difficult to differentiate. Our hope is that the review provides some clarity to the field in the specific context of schizophrenia.

Outpatient prescribing of opioids to adults diagnosed with mental disorders in the United States

BACKGROUND

Adults with mood and anxiety disorders have an increased likelihood of being prescribed opioids. The influence of other mental disorders, such as psychotic and attention disorders, on opioid prescribing patterns is less known.

METHODS

We studied a population-representative sample of 166,927 outpatient visits for adults with painful conditions from the 2002-2016 National Ambulatory Medical Care Survey and the 2002-2011 National Hospital Ambulatory Medical Care Survey. Logistic regression analyses examined the likelihood of opioid prescription among visits with specific mental disorder diagnoses (anxiety, attention, mood, psychotic, post-traumatic stress disorder (PTSD), opioid use, and non-opioid substance use), adjusted for covariates and weighted for the complex survey design. Secondary analyses stratified results by whether opioids were newly initiated or continued.

RESULTS

Opioids were prescribed at 16.8 % of visits. Mood, anxiety, and non-opioid substance use disorders were associated with higher likelihoods of opioid prescriptions, particularly for continued rather than first-time prescriptions. Psychotic disorders were strongly negatively associated with opioid prescriptions (adjusted odds ratio 0.44, 95 % CI 0.22-0.86). Diagnoses of PTSD and attention disorders were not associated with opioid prescribing.

CONCLUSIONS

Outpatient physicians are more likely to prescribe and refill opioids for adults with pain who present with mood, anxiety, and non-opioid substance use disorders, but not for those who present with PTSD or attention disorders. Patients with psychotic disorders and pain are markedly less likely to be prescribed opioids.

Differences in the Opioid Consumption of Terminally Ill Schizophrenic and Nonschizophrenic Cancer Patients: Analysis of Secondary National Population Data

CONTEXT

It is uncertain whether terminally ill schizophrenic cancer patients are hypoalgesic or have disparities in pain management.

OBJECTIVES

The objective of this study was to analyze the dosage of opioids used in terminally ill cancer patients with and without schizophrenia.

METHODS

This is a population-based retrospective cohort study based on data derived from the Taiwan National Health Insurance Research Database. Patients aged >20 years and newly diagnosed between 2000 and 2012 with at least one of the six most common cancers were included. After 1:4 matching, 1001 schizophrenic cancer patients comprised the schizophrenia cohort, while 4004 cancer patients without schizophrenia comprised the nonschizophrenia cohort. The percentage of opioid use, accumulated dose, and average daily dose near the end of life were analyzed for each cohort using multiple logistic and linear regression models.

RESULTS

The percentage of opioid use was lower in the schizophrenic cohort than the nonschizophrenic cohort during the last month before death (69.6% vs. 84.8%, odds ratio = 0.40, 95% CI = 0.34-0.48). The accumulated dose of opioid consumption was also lower in the schizophrenic cohort (2407 mg vs. 3694 mg, P value < 0.05).

CONCLUSION

Near the end of life, cancer patients with schizophrenia use less opioid than their nonschizophrenic counterparts. Cognitive impairment may be a cause in the disparity in end-of-life care for terminally ill schizophrenic cancer patients. Thus, we should formulate a more accurate pain scale system and pay attention to their need for pain treatment.

The aetiology of social deficits within mental health disorders: The role of the immune system and endogenous opioids

The American National Institute for Mental Health (NIMH) has put out a set of research goals that include a long-term plan to identify more reliable endogenous explanations for a wide variety of mental health disorders (Insel, 2013). In response to this, we have identified a major symptom that underlies multiple mental health disorders - social bonding dysfunction. We suggest that endogenous opioid abnormalities can lead to altered social bonding, which is a symptom of various mental health disorders, including depression, schizophrenia and ASD. This article first outlines how endogenous opioids play a role in social bonding. Then we show their association with the body's inflammation immune function, and review recent literature linking inflammation to mental health 'immunophenotypes'. We finish by explaining how these immunophenotypes may be caused by alterations in the endogenous opioid system. This is the first overview of the role of inflammation across multiple disorders where we provide a biochemical explanation for why immunophenotypes might exist across diagnoses. We propose a novel mechanism of how the immune system may be causing 'sickness-type' behaviours (fatigue, appetite change, social withdrawal and inhibited motivation) in those who have these immunophenotypes. We hope that this novel aetiology can be used as a basis for future research in mental health.

Genome-wide association study of multisite chronic pain in UK Biobank

Chronic pain is highly prevalent worldwide and represents a significant socioeconomic and public health burden. Several aspects of chronic pain, for example back pain and a severity-related phenotype ‘chronic pain grade’, have been shown previously to be complex heritable traits with a polygenic component. Additional pain-related phenotypes capturing aspects of an individual’s overall sensitivity to experiencing and reporting chronic pain have also been suggested as a focus for investigation. We made use of a measure of the number of sites of chronic pain in individuals within the UK general population. This measure, termed Multisite Chronic Pain (MCP), is a complex trait and its genetic architecture has not previously been investigated. To address this, we carried out a large-scale genome-wide association study (GWAS) of MCP in ~380,000 UK Biobank participants. Our findings were consistent with MCP having a significant polygenic component, with a Single Nucleotide Polymorphism (SNP) heritability of 10.2%. In total 76 independent lead SNPs at 39 risk loci were associated with MCP. Additional gene-level association analyses identified neurogenesis, synaptic plasticity, nervous system development, cell-cycle progression and apoptosis genes as enriched for genetic association with MCP. Genetic correlations were observed between MCP and a range of psychiatric, autoimmune and anthropometric traits, including major depressive disorder (MDD), asthma and Body Mass Index (BMI). Furthermore, in Mendelian randomisation (MR) analyses a causal effect of MCP on MDD was observed. Additionally, a polygenic risk score (PRS) for MCP was found to significantly predict chronic widespread pain (pain all over the body), indicating the existence of genetic variants contributing to both of these pain phenotypes. Overall, our findings support the proposition that chronic pain involves a strong nervous system component with implications for our understanding of the physiology of chronic pain. These discoveries may also inform the future development of novel treatment approaches.

Chronic pain is common worldwide and imposes a significant burden from a public health and socioeconomic perspective. The reasons why some individuals develop chronic pain and others do not are not fully understood. In this study we searched for genetic variants associated with chronic pain in a large general-population cohort. We also assessed how this genetic variation was correlated with a range of other diseases and traits, such as depression and BMI, and we tested for causal relationships between depression and chronic pain. We found that chronic pain was associated with several genes involved in brain function and development and was correlated with mental health and autoimmune traits (including depression, PTSD and asthma). We also found evidence for causal relationships between chronic pain and major depressive disorder. This work provides new insights into the genetics and underlying biology of chronic pain and may help to inform new treatment strategies.

Odor perception and hedonics in chronic schizophrenia and in first episode psychosis

BACKGROUND AND PURPOSE

The study evaluated olfactory performance and pleasantness rating of odors in patients with first episode psychosis (FEP) and chronic schizophrenia (SCH) with regard to the severity of psychopathological symptoms and plasma β-endorphin concentration.

PATIENTS AND METHODS

Twenty patients with FEP, 27 with SCH and 29 healthy individuals, were recruited to the research . The University of Pennsylvania Smell Identification Test (UPSIT), subjective odor hedonic judgment and plasma levels of β-endorphin (BE) assay were performed in all participants.

RESULTS

Individuals with SCH revealed higher BE concentration than other study groups (P=0.000). All patients identified pleasant odors poorer than controls, however, SCH made more identification errors (P=0.000) than those with FEP. Moreover, participants with FEP rated pleasant odors as more pleasant than individuals with chronic schizophrenia and healthy controls (P=0.009). Nevertheless, higher β-endorphin level was related with lower scores in pleasant odor identification (Rs=-0.452; P=0.046) and more severe psychotic symptoms in FEP sample. Chronic schizophrenia patients did not demonstrate any relationship between symptom severity, odor identification performance and β-endorphin concentration. No relationship was found between BE concentration and hedonic judgment of the presented odors among all study groups. Chronically ill subjects identified odors significantly more poorly than those with first episode psychosis. Deficits in identifying pleasant odors might not be the only potential risk factor for undergoing chronic, recurrent schizophrenia. All patients subjectively overrated pleasant odors. Those with SCH and more severe negative symptoms made significantly more identification errors.

CONCLUSION

The endogenous morphine system deregulation is observed in first episode psychosis as well as in chronic schizophrenia. In first episode schizophrenia higher beta-endorphin concentration is related to pleasant odor identification deficit.

The Schizophrenia Oral Health Profile: Development and Feasibility

Background

The aim of this study was to present the different stages of development of the Schizophrenia Oral Health Profile (SOHP) questionnaire, aimed at assessing oral disorders and their impacts on functioning and psychosocial wellbeing for patients with schizophrenia (PWS) and to give the results of a feasibility study conducted in France

Materials and methods

The first step of this qualitative study was semi-structured interviews were conducted with 20 PWS and 6 health professionals (HP). A focus group integrating 4 PWS and 4 HP was also organised to identify the items of the SOHP. The data were analysed using a thematic analysis. Second, a feasibility study was conducted in a sample of 30 PWS who answered the SOHP questionnaire. The acceptability and understanding of the SOHP were evaluated, using a specific questionnaire.

Results

The semi-structured interviews and focus groups included 34 individuals in total. Items’ selection was done with several stages and led to a SOHP scale with 53 final items related to oral disorders and their impacts on functioning and psychosocial well-being. These items were classified in 13 preselected dimensions including one additional module related to the side effects of medications (11 items). The feasibility study showed good acceptability and understanding of the items of the SOHP scale.

Conclusions

The psychometric validation of the SOHP scale, involving a large sample of PWS, is currently in progress. The SOHP is important to evaluate PWS oral health needs and to offer appropriate strategies to improve oral health of this persons.

Trial registration

Clinical Trials Gov NCT02730832. Date registered: 21 March, 2016.

Overrated hedonic judgment of odors in patients with schizophrenia

AIMS

The odor identification ability and its hedonic judgment in patients with schizophrenia were evaluated in the study. The association between olfactory performance and negative symptoms and β-endorphin concentration was also analyzed.

METHODS

Study groups consisted of 23 patients with negative symptoms (PN) and 25 without predominant negative symptoms (PP) and 21 healthy individuals. The University of Pennsylvania Smell Identification Test, odor hedonic evaluation, and plasma concentrations of β-endorphin assay in all participants were performed.

RESULTS

PN perceived the poorer olfactory identification; nevertheless, they evaluated unpleasant odors as more pleasant than PP and controls. Beta-endorphin concentration was significantly higher among PN than in other study groups. No association was observed between β-endorphin and odors identification and odor hedonic judgment among all study groups.

CONCLUSIONS

There is potential relationship between increased β-endorphin concentration and severity of negative symptoms. Patients with predominant negative symptoms tend to evaluate odors as significantly more pleasant. Individuals with this subtype of schizophrenia might present specific, altered pattern of smell identification and hedonic judgment. Presumably, β-endorphin has no direct influence on olfactory identification performance and hedonic judgment in schizophrenia.

Evidence for differential opioid use disorder in schizophrenia in an addiction treatment population

Although people diagnosed with schizophrenia are known to have elevated risks of abuse and dependence for nicotine, alcohol, cocaine, and cannabis, it is less clear if schizophrenia is associated with higher rates of opioid use disorders compared to either the general population or individuals with other major psychiatric disorders. Here we examine a large publicly available database from substance abuse treatment centers to compare how frequently patients with schizophrenia report problems with heroin or other opioid drugs compared to other major drugs of abuse. For comparison, the pattern of substance abuse in schizophrenia is contrasted with individuals with major depression, bipolar disorder, and the entire sample of individuals seeking substance abuse treatment. We find that a significantly lower proportion of patients with schizophrenia are reported to have problems with heroin (5.1%) relative to the entire treatment population (18.2%). The schizophrenia sample also had a significantly lower proportion of individuals with a non-heroin opioid problem (7.2%) compared to the entire treatment population (14.8%), patients with depression (23%), and patients with bipolar disorder (17.3%). In contrast, the schizophrenia sample had significantly higher proportions of individuals with problems with alcohol, cocaine, and cannabis relative to the treatment population. Although these data do not allow conclusions on the relative rate of opioid addiction in schizophrenia compared to the general population, the results suggest a discrepancy in patterns of drug choice that may aid our understanding of schizophrenia and substance use comorbidity.

Past Pain Experience and Experimentally induced Pain Perception

Many intercurrent factors may be involved in the modulation of the pain message and its expression, such as the previous experience of pain built along the life. In this study, we aimed to determine whether susceptibility to experimentally induced pain is differentially influenced by the individual previous painful experience in subjects with schizophrenia (SC) major depression (MD), and controls (C).

METHODS

The SC (30), MD (32) and C (30) groups participated in experimental pain tests (application of pressure and induction of ischemia) after a semi-structured interview to make an inventory of the previous painful experiences, and the evaluation of anxiety either with autonomic (heart rate, blood pressure) or psychological (Hospital Anxiety Depression scale HAD) measures, and catastrophism.

RESULTS

The reported pain intensities, severities, duration, of the previous pain events, and the number of previous painful events were equivalent in the three groups, except for the number of painful events experimented before the last six months which was lower in the MD group. Experimental pain sensitivity was influenced by the diagnosis, the HAD scores or the number and intensities of previous lived painful events.

CONCLUSION

The lack of a past experience of pain was comparable for the different groups, suggesting that psychiatric disorders do not affect the experience of pain associated with daily life or past events. For each subject, the reported previous experience of pain influences the present feeling of pain.

Impact of reward on pain threshold and tolerance to experimental pain (Cold Pressor Task) in healthy subjects and patients with schizophrenia

Reduced pain sensitivity is considered as a potential endophenotype of schizophrenia. Patient's motivation in pain experimental studies was neither assessed nor controlled. This study aimed to assess the effect of reward on pain in patients with schizophrenia compared to controls. Rewarded subjects showed higher pain threshold and tolerance compared to unrewarded subjects. Pain tolerance was significantly lower in patients than in controls when they were not rewarded. Reward resulted in an increase of pain tolerance with a higher manner in patients. This study suggests that better control of motivational aspects could improve assessment of pain sensitivity in schizophrenia.

Olfactory identification in patients with schizophrenia - the influence of β-endorphin and calcitonin gene-related peptide concentrations

BACKGROUND

The relationship between the olfactory system and emotional processing is an area of growing interest in schizophrenia research. Both the orbitofrontal cortex and amygdala are involved in the processing of olfactory information, and olfactory deficits may be also influenced by endogenous opioids and calcitonin gene-related peptide (CGRP), which is probably involved in dopaminergic transmission. However, the relationship between endorphins and dopaminergic transmission has not been fully explored.

METHODS

Odor identification performance and valence interaction was evaluated among 50 schizophrenic patients and 50 controls. Schizophrenia symptoms were assessed using the Positive and Negative Syndrome Scale (PANSS). All study participants were subjected to the University of Pennsylvania Smell Identification Test (UPSIT), blood β-endorphin (BE) and CGRP measurement.

RESULTS

Insignificantly higher BE concentrations were observed in the patient group, while significantly higher UPSIT scores were seen in controls (mean UPSIT 32.48 vs 26.82). The patients demonstrated significantly more identification errors for pleasant (P=0.000) and neutral (P=0.055) odors than for unpleasant odors. Patients with higher BE concentrations made more identification errors concerning pleasant (R_s=-0.292; P=0.04) and neutral odors (R_s=-0.331; P=0.019). Although the concentration of CGRP was significantly higher in the patient sample (P<0.001), no relationship was observed between concentration and UPSIT performance. A strong negative correlation was observed between PANSS N score and UPSIT total score (R_s=-0.646; P=0.000), between PANSS N score and identification by valence for pleasant and neutral odors (UPSIT n/16: R_s=-0.450, P=0.001; UPSIT n/15: R_s=-0.586, P=0.000), and a weak negative correlation between PANSS N score and identification of unpleasant odors (UPSIT n/9: R_s=-0.325, P=0.021).

CONCLUSIONS

Schizophrenic patients present a unique pattern of smell identification characterized by aberrant hedonic ratings for pleasant odors but not unpleasant ones. Individuals with predominant negative symptoms and higher BE concentrations are most able to identify negative odors.

Endogenous Opiates and Behavior: 2015

This paper is the thirty-eighth consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2015 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior, and the roles of these opioid peptides and receptors in pain and analgesia, stress and social status, tolerance and dependence, learning and memory, eating and drinking, drug abuse and alcohol, sexual activity and hormones, pregnancy, development and endocrinology, mental illness and mood, seizures and neurologic disorders, electrical-related activity and neurophysiology, general activity and locomotion, gastrointestinal, renal and hepatic functions, cardiovascular responses, respiration and thermoregulation, and immunological responses.

Developmental suppression of schizophrenia-associated miR-137 alters sensorimotor function in zebrafish

The neurodevelopmentally regulated microRNA miR-137 was strongly implicated as risk locus for schizophrenia in the most recent genome wide association study coordinated by the Psychiatric Genome Consortium (PGC). This molecule is highly conserved in vertebrates enabling the investigation of its function in the developing zebrafish. We utilized this model system to achieve overexpression and suppression of miR-137, both transiently and stably through transgenesis. While miR-137 overexpression was not associated with an observable specific phenotype, downregulation by antisense morpholino and/or transgenic expression of miR-sponge RNA induced significant impairment of both embryonic and larval touch-sensitivity without compromising overall anatomical development. We observed miR-137 expression and activity in sensory neurons including Rohon-Beard neurons and dorsal root ganglia, two neuronal cell types that confer touch-sensitivity in normal zebrafish, suggesting a role of these cell types in the observed phenotype. The lack of obvious anatomical or histological pathology in these cells, however, suggested that subtle axonal network defects or a change in synaptic function and neural connectivity might be responsible for the behavioral phenotype rather than a change in the cellular morphology or neuroanatomy.

Mu-Opioid (MOP) receptor mediated G-protein signaling is impaired in specific brain regions in a rat model of schizophrenia

Schizophrenia is a complex mental health disorder. Clinical reports suggest that many patients with schizophrenia are less sensitive to pain than other individuals. Animal models do not interpret schizophrenia completely, but they can model a number of symptoms of the disease, including decreased pain sensitivities and increased pain thresholds of various modalities. Opioid receptors and endogenous opioid peptides have a substantial role in analgesia. In this biochemical study we investigated changes in the signaling properties of the mu-opioid (MOP) receptor in different brain regions, which are involved in the pain transmission, i.e., thalamus, olfactory bulb, prefrontal cortex and hippocampus. Our goal was to compare the transmembrane signaling mediated by MOP receptors in control rats and in a recently developed rat model of schizophrenia. Regulatory G-protein activation via MOP receptors were measured in [(35)S]GTPγS binding assays in the presence of a highly selective MOP receptor peptide agonist, DAMGO. It was found that the MOP receptor mediated activation of G-proteins was substantially lower in membranes prepared from the 'schizophrenic' model rats than in control animals. The potency of DAMGO to activate MOP receptor was also decreased in all brain regions studied. Taken together in our rat model of schizophrenia, MOP receptor mediated G-proteins have a reduced stimulatory activity compared to membrane preparations taken from control animals. The observed distinct changes of opioid receptor functions in different areas of the brain do not explain the augmented nociceptive threshold described in these animals.

Toward Precision Psychiatry: Statistical Platform for the Personalized Characterization of Natural Behaviors

There is a critical need for new analytics to personalize behavioral data analysis across different fields, including kinesiology, sports science, and behavioral neuroscience. Specifically, to better translate and integrate basic research into patient care, we need to radically transform the methods by which we describe and interpret movement data. Here, we show that hidden in the “noise,” smoothed out by averaging movement kinematics data, lies a wealth of information that selectively differentiates neurological and mental disorders such as Parkinson’s disease, deafferentation, autism spectrum disorders, and schizophrenia from typically developing and typically aging controls. In this report, we quantify the continuous forward-and-back pointing movements of participants from a large heterogeneous cohort comprising typical and pathological cases. We empirically estimate the statistical parameters of the probability distributions for each individual in the cohort and report the parameter ranges for each clinical group after characterization of healthy developing and aging groups. We coin this newly proposed platform for individualized behavioral analyses “precision phenotyping” to distinguish it from the type of observational–behavioral phenotyping prevalent in clinical studies or from the “one-size-fits-all” model in basic movement science. We further propose the use of this platform as a unifying statistical framework to characterize brain disorders of known etiology in relation to idiopathic neurological disorders with similar phenotypic manifestations.