Biological markers for anxiety disorders, OCD and PTSD: A consensus statement. Part II: Neurochemistry, neurophysiology and neurocognition

Towards zebrafish models to unravel translational insights of obsessive-compulsive disorder: A neurobehavioral perspective

Obsessive-compulsive disorder (OCD) is a chronic and debilitating illness that has been considered a polygenic and multifactorial disorder, challenging effective therapeutic interventions. Although invaluable advances have been obtained from human and rodent studies, several molecular and mechanistic aspects of OCD etiology are still obscure. Thus, the use of non-traditional animal models may foster innovative approaches in this field, aiming to elucidate the underlying mechanisms of disease from an evolutionary perspective. The zebrafish (Danio rerio) has been increasingly considered a powerful organism in translational neuroscience research, especially due to the intrinsic features of the species. Here, we outline target mechanisms of OCD for translational research, and discuss how zebrafish-based models can contribute to explore neurobehavioral aspects resembling those found in OCD. We also identify possible advantages and limitations of potential zebrafish-based models, as well as highlight future directions in both etiological and therapeutic research. Lastly, we reinforce the use of zebrafish as a promising tool to unravel the biological basis of OCD, as well as novel pharmacological therapies in the field.

Implications of Kynurenine Pathway Metabolism for the Immune System, Hypothalamic-Pituitary-Adrenal Axis, and Neurotransmission in Alcohol Use Disorder

In recent years, there has been a marked increase in interest in the role of the kynurenine pathway (KP) in mechanisms associated with addictive behavior. Numerous reports implicate KP metabolism in influencing the immune system, hypothalamic-pituitary-adrenal (HPA) axis, and neurotransmission, which underlie the behavioral patterns characteristic of addiction. An in-depth analysis of the results of these new studies highlights interesting patterns of relationships, and approaching alcohol use disorder (AUD) from a broader neuroendocrine-immune system perspective may be crucial to better understanding this complex phenomenon. In this review, we provide an up-to-date summary of information indicating the relationship between AUD and the KP, both in terms of changes in the activity of this pathway and modulation of this pathway as a possible pharmacological approach for the treatment of AUD.

Assessment of salivary cortisol dynamics in an infantry training exercise: a pilot study

INTRODUCTION

Measuring cortisol during military training offers insights into physiological responses to stress. We attempted precisely timed, cortisol awakening response (CAR) and pre-sleep cortisol (PSC), and diurnal slope (peak morning minus evening cortisol), during a British Army exercise. We aimed to understand cortisol dynamics and evaluate the feasibility of CAR and PSC in this environment.

METHOD

Setting: high-intensity, 10-day infantry exercise. Participants: regular infantry soldiers exercising (EX, n=25) or headquarters-based (HQ, n=6). Participants undertook PSC and WAKE and WAKE+30 min samples after 1-2 days, 5-6 days and 9-10 days. Wrist-worn GENEActiv accelerometers were used to assess sleep duration in EX only. Samples taken ±15 min from prespecified time points were deemed adherent. Validated questionnaires were used to measure resilience and perceived stress. Cortisol and cortisone were measured simultaneously by liquid chromatography tandem mass spectrometry.

RESULTS

From adherent participants' samples, CAR was positive and tended to decrease as the exercise progressed. From all available data, HQ demonstrated greater diurnal slope than EX (F=7.68, p=0.02), reflecting higher morning cortisol (F=4.72, p=0.038) and lower PSC (p=0.04). No differences were seen in cortisol:cortisone ratio. 26.1% of CAR samples were adherent, with moderately strong associations between adherence and stress (r=0.41, p=0.009) but no association between adherence and day of exercise (χ2=0.27, p=0.8), sleep duration (r=-0.112, p=0.43) or resilience (r=-0.79, p=0.75). Test-retest reliability ratings for CAR were Cronbach's α of 0.48, -11.7 and 0.34 for the beginning, middle and end of the exercise, respectively.

CONCLUSIONS

We observed a reduction in morning cortisol and decreased diurnal slope during a high-intensity military exercise, compared with the HQ comparator cohort in whom diurnal slope was preserved. A carefully timed CAR was not feasible in this setting.

Research in China about the biological mechanisms that potentially link socioenvironmental changes and mental health: a scoping review

China's rapid socioeconomic development since 1990 makes it a fitting location to summarise research about how biological changes associated with socioenvironmental changes affect population mental health and, thus, lay the groundwork for subsequent, more focused studies. An initial search identified 308 review articles in the international literature about biomarkers associated with 12 common mental health disorders. We then searched for studies conducted in China that assessed the association of the identified mental health related-biomarkers with socioenvironmental factors in English-language and Chinese-language databases. We located 1330 articles published between 1 January 1990 and 1 August 2021 that reported a total of 3567 associations between 56 specific biomarkers and 11 socioenvironmental factors: 3156 (88·5%) about six types of environmental pollution, 381 (10·7%) about four health-related behaviours (diet, physical inactivity, internet misuse, and other lifestyle factors), and 30 (0·8%) about socioeconomic inequity. Only 245 (18·4%) of the papers simultaneously considered the possible effect of the biomarkers on mental health conditions; moreover, most of these studies assessed biomarkers in animal models of mental disorders, not human subjects. Among the 245 papers, mental health conditions were linked with biomarkers of environmental pollution in 188 (76·7%), with biomarkers of health-related behaviours in 48 (19·6%), and with biomarkers of socioeconomic inequality in 9 (3·7%). The 604 biomarker-mental health condition associations reported (107 in human subjects and 497 in animal models) included 379 (62·7%) about cognitive functioning, 117 (19·4%) about anxiety, 56 (9·3%) about depression, 21 (3·5%) about neurodevelopmental conditions, and 31 (5·1%) about neurobehavioural symptoms. Improved understanding of the biological mechanisms linking socioenvironmental changes to community mental health will require expanding the range of socioenvironmental factors considered, including mental health outcomes in more of the studies about the association of biomarkers with socioenvironmental factors, and increasing the proportion of studies that assess mental health outcomes in humans.

Efficacy of acupuncture (Jin's three-needle) on motor symptoms and anxiety in patients with Parkinson's disease: protocol for a multicentre, randomised, assessor-blinded clinical trial

INTRODUCTION

Parkinson's disease (PD) has a significant impact on a substantial number of individuals in China. Notably, 31% of patients with PD also grapple with the additional burden of anxiety. This dual challenge of managing both PD and anxiety underscores the complexity of the condition and the diverse range of symptoms patients may experience. Considering the circumstances, the cost and potential drawbacks associated with traditional antiparkinsonian drugs become increasingly relevant. Acupuncture emerges as a significant non-pharmacological adjunct therapy. Offering a potentially safer and more cost-effective option, acupuncture addresses the pressing need for holistic and complementary treatments that may alleviate both the motor symptoms of PD and the accompanying anxiety.

METHODS AND ANALYSIS

This is a multicentre, randomised controlled and assessor-blind trial. A total of 210 eligible patients with PD will be randomly assigned (1:1) to Jin's three-needle (JTN) acupuncture group or waitlist (WL) group. Patients in the JTN group will receive acupuncture therapy three times per week for 4 weeks. Patients in the WL group will maintain their original dosage of antiparkinsonian drugs and receive acupuncture therapy after the observation period. The primary outcome measure will be the Unified Parkinson's Disease Rating Scale score. The secondary outcome measures will be the scores of the Hoehn-Yahr Rating Scale, Unified Dyskinesia Rating Scale, Non-Motor Symptoms Scale, 39-item Parkinson's Disease Questionnaire, Parkinson Anxiety Scale, Hamilton Anxiety Scale, Hamilton Depression Scale, Zarit burden interview and the level of cortisol and adrenocorticotropic hormone. The evaluation will be executed at baseline, the end of the treatment and a follow-up period.

ETHICS AND DISSEMINATION

The study was approved by the Ethics Committee of the First Affiliated Hospital of Guangzhou University of Chinese Medicine (K[2023]014). All patients have to provide written, informed consent. The study will be disseminated through presentations in peer-reviewed international journals and at national and international conferences.

TRIAL REGISTRATION NUMBER

Chinese Clinical Trial Registry; ChiCTR2300074675.

Are decreased cocaine- and amphetamine regulated transcript and Agouti- related peptide levels associated Eating behavior in medication-free children with attention deficit and hyperactivity disorder?

This study aimed to investigate plasma levels of cocaine- and amphetamine-regulated transcript (CART), agouti-related protein (AgRP), cholecystokinin (CCK) and peptide YY (PYY) and their relationship with eating behaviors among children with attention deficit hyperactivity disorder (ADHD) and healthy controls. A total of 94 medication-free children with ADHD and 82 controls aged 8-14 years were included in this study. The Plasma levels of CART, AgRP, CCK and PYY were measured using enzyme-linked immunosorbent assay kits. The Children's Eating Behavior Questionnaire (CEBQ) was used to assess eating behaviors in children. CART and AgRP levels were found to be significantly lower in the ADHD group than in the control group, while CCK levels were found to be significantly higher in the ADHD group than in the control group. However, there was no significant difference in PYY levels between the groups. Compared to controls, those with ADHD demonstrated significantly higher scores on the CEBQ subscales of food responsiveness, emotional overeating, desire to drink, enjoyment of food, and food fussiness, and significantly lower scores on the slowness of eating subscale. CART was significantly correlated with emotional overeating and enjoyment of food scores, while AgRP was significantly correlated with emotional undereating scores. Covariance analysis was performed by controlling potential confounders such as body mass index, age and sex, and the results were found to be unchanged. It was concluded that CART, AgRP, and CCK may play a potential role in the pathogenesis of ADHD.

The definition of treatment resistance in anxiety disorders: a Delphi method-based consensus guideline

Anxiety disorders are very prevalent and often persistent mental disorders, with a considerable rate of treatment resistance which requires regulatory clinical trials of innovative therapeutic interventions. However, an explicit definition of treatment-resistant anxiety disorders (TR-AD) informing such trials is currently lacking. We used a Delphi method-based consensus approach to provide internationally agreed, consistent and clinically useful operational criteria for TR-AD in adults. Following a summary of the current state of knowledge based on international guidelines and an available systematic review, a survey of free-text responses to a 29-item questionnaire on relevant aspects of TR-AD, and an online consensus meeting, a panel of 36 multidisciplinary international experts and stakeholders voted anonymously on written statements in three survey rounds. Consensus was defined as ≥75% of the panel agreeing with a statement. The panel agreed on a set of 14 recommendations for the definition of TR-AD, providing detailed operational criteria for resistance to pharmacological and/or psychotherapeutic treatment, as well as a potential staging model. The panel also evaluated further aspects regarding epidemiological subgroups, comorbidities and biographical factors, the terminology of TR-AD vs. "difficult-to-treat" anxiety disorders, preferences and attitudes of persons with these disorders, and future research directions. This Delphi method-based consensus on operational criteria for TR-AD is expected to serve as a systematic, consistent and practical clinical guideline to aid in designing future mechanistic studies and facilitate clinical trials for regulatory purposes. This effort could ultimately lead to the development of more effective evidence-based stepped-care treatment algorithms for patients with anxiety disorders.

Cerebrospinal fluid findings in patients with obsessive-compulsive disorder, Tourette syndrome, and PANDAS: A systematic literature review

BACKGROUND

Obsessive-compulsive disorder (OCD) and Tourette syndrome (TS) are related mental disorders that share genetic, neurobiological, and phenomenological features. Pediatric autoimmune neuropsychiatric disorder associated with streptococcal infections (PANDAS) is a neuropsychiatric autoimmune disorder with symptoms of OCD and/or TS associated with streptococcal infections. Therefore, PANDAS represents a strong link between OCD, TS, and autoimmunity. Notably, cerebrospinal fluid (CSF) analyses can provide insight into the central nervous processes in OCD, TS, and PANDAS.

METHODS

A systematic literature search according to the PRISMA criteria was conducted to collect all CSF studies in patients with OCD, TS, and PANDAS. The total number of cases and the heterogeneity of the low number of studies were not sufficient for a meta-analysis to provide a high level of evidence. Nevertheless, meta-analytical statistics could be performed for glutamate, 5-hydroxyindoleacetic acid (degradation product of serotonin), homovanillic acid (degradation product of dopamine), 3-methoxy-4-hydroxyphenylglycol (major metabolite of noradrenaline), and corticotropin-releasing hormone (CRH) in OCD. A risk-of-bias assessment was implemented using the Cochrane ROBINS-E tool.

RESULTS

Meta-analytical testing identified elevated glutamate levels in the CSF of OCD patients compared with healthy controls, while no significant differences were found in other neurotransmitters or CRH. Single studies detected novel neuronal antibodies in OCD patients and elevated oligoclonal bands in TS patients. For TS and PANDAS groups, there was a dearth of data. Risk of bias assessment indicated a substantial risk of bias in most of the included studies.

CONCLUSIONS

This systematic review of available CSF data shows that too few studies are currently available for conclusions with good evidence. The existing data indicates glutamate alterations in OCD and possible immunological abnormalities in OCD and TS. More CSF studies avoiding sources of bias are needed.

Use of Post-mortem Brain Tissue in Investigations of Obsessive- Compulsive Disorder: A Systematic Review

BACKGROUND

Post-mortem examination of the brain is a key strategy to increase our understanding of the neurobiology of mental disorders. While extensive post-mortem research has been undertaken on some mental disorders, others appear to have been relatively neglected.

OBJECTIVE

The objective of the study was to conduct a systematic review of post-mortem research on obsessive-compulsive disorder (OCD).

METHODS

A systematic review was performed in accordance with PRISMA guidelines to provide an overview of quantitative, qualitative, or mixed methods primary research studies on OCD. Search platforms included NCBI Pubmed, SCOPUS, and Web of Science.

RESULTS

A total of 52 publications were found, and after the removal of works not meeting the inclusion criteria, six (6) peer-reviewed publications remained. These post-mortem studies have provided data on DNA methylation, cellular and molecular alterations, and gene expression profiling in brain areas associated with OCD.

DISCUSSION AND CONCLUSION

Included studies highlight the potential value of post-mortem brains from well-characterized individuals with OCD and suggest the need for additional work in this area.

Modeling Sex-Bias in Anxiety: Pros and Cons of a Larval Zebrafish Model

Anxiety disorders are the most prevalent psychiatric disorders, exhibiting strong female bias. Clinical studies implicate declining estradiol levels in the exacerbation of anxiety symptoms in the premenstrual phase of the menstrual cycle. This study aimed to simulate estradiol fluctuation-linked anxiety behavior in larval zebrafish, using an estradiol treatment withdrawal model. Contrary to model aims, estradiol treatment withdrawal decreased both basal activity and anxiety-like hyperlocomotion (ANOVA main effect of dose, P < 0.0001 and P < 0.01, respectively) in the light/dark transition test. The accuracy of the estradiol washout model was not improved by longer durations of treatment or withdrawal. Basal activity was slightly altered by supraphysiological concentrations of WAY-200070 in the absence of added estradiol. Estrogen receptor (ER) β expression was not upregulated in larvae exposed to physiologically relevant, low concentrations of estradiol. Longer exposure to low concentrations of estradiol increased antioxidant capacity (P < 0.01). In addition, acute exposure to low concentrations of estradiol increased basal activity. Data suggest that in the current models, estradiol-associated altered activity levels were linked to more favorable redox status, rather than reflecting altered anxiety levels. As such, it is recommended that zebrafish larval behavioral analysis be conducted in parallel with mechanistic studies such as redox indicators, for investigations focused on ER signaling.

Electrophysiological biomarkers in dual pathology

INTRODUCTION

The co-occurrence of substance use disorder with at least one other mental disorder is called dual pathology, which in turn is characterised by heterogeneous symptoms that are difficult to diagnose and have a poor response to treatment. For this reason, the identification and validation of biomarkers is necessary. Within this group, possible electroencephalographic biomarkers have been reported to be useful in diagnosis, treatment and follow-up, both in neuropsychiatric conditions and in substance use disorders. This article aims to review the existing literature on electroencephalographic biomarkers in dual pathology.

METHODS

A narrative review of the literature. A bibliographic search was performed on the PubMed, Science Direct, OVID, BIREME and Scielo databases, with the keywords: electrophysiological biomarker and substance use disorder, electrophysiological biomarker and mental disorders, biomarker and dual pathology, biomarker and substance use disorder, electroencephalography, and substance use disorder or comorbid mental disorder.

RESULTS

Given the greater amount of literature found in relation to electroencephalography as a biomarker of mental illness and substance use disorders, and the few articles found on dual pathology, the evidence is organised as a biomarker in psychiatry for the diagnosis and prediction of risk and as a biomarker for dual pathology.

CONCLUSIONS

Although the evidence is not conclusive, it suggests the existence of a subset of sites and mechanisms where the effects of psychoactive substances and the neurobiology of some mental disorders could overlap or interact.

The involvement of the adrenergic system in feeding and eating disorders. A systematic review

BACKGROUND

Adrenergic dysregulation has been proposed as a possible underlying mechanism in feeding and eating disorders (FED). This review aims to synthesise the current evidence on the role of adrenergic dysregulation in the pathogenesis and management of FED.

METHODS

A systematic review was conducted in MEDLINE, Cochrane Library, and Clinicaltrials.gov. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) was adopted. Preclinical, clinical, and pharmacological studies assessing the adrenergic system in FED were included.

RESULTS

Thirty-one out of 1415 recognised studies were included. Preclinically, studies on adrenaline's anorectic impact, receptor subtypes, and effects on hepatic function in rats show that catecholamine anorexia is primarily alpha-adrenergic, whereas beta-adrenergic anorexia can be obtained only after puberty, implying an impact of sexual hormones. Clinically, catecholamine levels may be higher in FED patients than in healthy controls (HC). Individuals with anorexia nervosa (AN) may show higher epinephrine-induced platelet aggregability response than HC. Pharmacological trials suggest that the alpha-2-adrenergic medication clonidine may not lower AN symptoms, but agents regulating the adrenaline-noradrenaline neurotransmission (bupropion, reboxetine, duloxetine, sibutramine) have been found to improve binge eating symptoms.

CONCLUSION

Adrenergic dysregulation may be involved in the pathophysiology of FED. More research is needed to comprehend underlying mechanisms and treatment implications.

Sex-dependent association of DNA methylation of HPA axis-related gene FKBP5 with obsessive-compulsive disorder

AIMS

Although hypothalamic-pituitary-adrenal (HPA) axis dysregulation in obsessive-compulsive disorder (OCD) has been reported, epigenetic changes in HPA axis-related genes have not been well studied in OCD. The present study investigated whether the epigenetic regulation of FK506-binding protein 51 gene (FKBP5) intron 7 is associated with OCD status in each sex. In addition, relationships among the DNA methylation levels of FKBP5 intron 7, OCD status and early-life trauma were explored.

METHODS

A total of 267 patients with OCD and 201 controls aged between 18 and 40 years were recruited. Demographic and clinical assessment, FKBP5 rs1360780 genotyping, and pyrosequencing of FKBP5 intron 7 were conducted. DNA was extracted from peripheral blood leucocytes. First, multivariate analysis of covariance for differential DNA methylation levels between OCD patients and controls was conducted with adjustment for FKBP5 rs1360780 genotype, early-life trauma, depressive symptoms, and age as covariates in each sex. Next, path analysis was conducted to determine the mediation effects of DNA methylation levels of FKBP5 between early-life trauma and OCD status. In addition, sensitivity analyses for medication and lifetime major depression were also performed.

RESULTS

DNA methylation at the FKBP5 intron 7 CpG site was significantly lower in men with OCD, compared to controls (mean difference -1.33%, 95% CI -2.11 to -0.55, p < 0.001). The results remained significant for drug naïve or free subjects (mean difference -1.27%, 95% CI -2.18 to -0.37, p = 0.006, in men) and for subjects without lifetime major depressive disorder (mean difference -1.60%, 95% CI -2.54 to -0.66, p < 0.001, in men). The mediation effect of DNA methylation levels was not significant between early-life trauma and OCD status.

CONCLUSION

These findings suggest that epigenetic factors of HPA axis-related gene FKBP5 may play a role in the pathogenesis of OCD. Further studies are needed to determine how altered DNA methylation of FKBP5 intron 7 and HPA axis function are involved in OCD.

The relationship of separation anxiety with the age of onset of panic disorder

AIM

This study aimed to investigate whether separation anxiety (SA) constitutes a dimension related to age at onset of panic disorder (PD), in homogeneous subgroups of outpatients with PD, based on their age of onset and symptom severity.

METHODS

A sample of 232 outpatients with PD was assessed with the Panic Disorder Severity Scale (PDSS) and the Sheehan Disability Scale (SDS) for functional impairments. Separation anxiety was evaluated using structured interviews and questionnaires. We applied a K-Means Cluster Analysis based on the standardized "PD age of onset" and "the PDSS total score" to identify distinct but homogeneous groups.

RESULTS

We identified three groups of patients: group 1 ("PD early onset/severe", N = 97, 42%, onset 23.2 ± 6.7 years), group 2 ("PD early onset/not severe", N = 76, 33%, onset 23.4 ± 6.0 years) and group 3 ("PD adult onset/not severe", N = 59, 25%, onset 42.8 ± 7.0 years). Patients with early onset/severe PD had significantly higher scores on all SA measures than PD late-onset/not severe. Regression analyses showed that SA scores, but not PDSS scores, were predictive of impairment in SDS work/school, social life, and family functioning domains.

CONCLUSIONS

Our data indicate a significant relationship between SA and PD with an earlier age of onset and an impact on individual functioning. This may have important implications for implementing preventive interventions targeting early risk factors for the subsequent onset of PD.

Capnography-Assisted Learned, Monitored (CALM) breathing therapy for dysfunctional breathing in COPD: A bridge to pulmonary rehabilitation

BACKGROUND

Although dyspnea is a primary symptom of chronic obstructive pulmonary disease (COPD), its treatment is suboptimal. In both COPD and acute anxiety, breathing patterns become dysregulated, contributing to abnormal CO2, dyspnea, and inefficient recovery from breathing challenges. While pulmonary rehabilitation (PR) improves dyspnea, only 1-2% of patients access it. Individuals with anxiety who use PR have worse outcomes.

METHODS

We present the protocol of a randomized controlled trial designed to determine the feasibility and acceptability of a new, four-week mind-body intervention that we developed, called "Capnography-Assisted Learned, Monitored (CALM) Breathing," as an adjunct to PR. Eligible participants are randomized in a 1:1 ratio to either CALM Breathing program or Usual Care. CALM Breathing consists of 10 core, slow breathing exercises combined with real time biofeedback (of end-tidal CO2, respiratory rate, and airflow) and motivational interviewing. CALM Breathing promotes self-regulated breathing, linking CO2 changes to dyspnea and anxiety symptoms and targeting breathing efficiency and self-efficacy in COPD. Participants are randomized to CALM Breathing or a Usual Care control group.

RESULTS

Primary outcomes include feasibility and acceptability metrics of recruitment efficiency, participant retention, intervention adherence and fidelity, PR facilitation, patient satisfaction, and favorable themes from interviews. Secondary outcomes include breathing biomarkers, symptoms, health-related quality of life, six-minute walk distance, lung function, mood, physical activity, and PR utilization and engagement.

CONCLUSION

By disrupting the cycle of dyspnea and anxiety, and providing a needed bridge to PR, CALM Breathing may address a substantive gap in healthcare and optimize treatment for patients with COPD.

Pharmacological modulation of conditioned fear in the fear-potentiated startle test: a systematic review and meta-analysis of animal studies

RATIONALE AND OBJECTIVES

Fear conditioning is an important aspect in the pathophysiology of anxiety disorders. The fear-potentiated startle test is based on classical fear conditioning and over the years, a broad range of drugs have been tested in this test. Synthesis of the available data may further our understanding of the neurotransmitter systems that are involved in the expression of conditioned fear.

METHODS

Following a comprehensive search in Medline and Embase, we included 68 research articles that reported on 103 drugs, covering 56 different drug classes. The systematic review was limited to studies using acute, systemic drug administration in naive animals.

RESULTS

Qualitative data synthesis showed that most clinically active anxiolytics, but not serotonin-reuptake inhibitors, reduced cued fear. Anxiogenic drugs increased fear potentiation in 35% of the experiments, reduced fear potentiation in 29% of the experiments, and were without effect in 29% of the experiments. Meta-analyses could be performed for five drug classes and showed that benzodiazepines, buspirone, 5-HT1A agonists, 5-HT1A antagonists, and mGluR2,3 agonists reduced cued conditioned fear. The non-cued baseline startle response, which may reflect contextual anxiety, was only significantly reduced by benzodiazepines and 5-HT1A antagonists. No associations were found between drug effects and methodological characteristics, except for strain.

CONCLUSIONS

The fear-potentiated startle test appears to have moderate to high predictive validity and may serve as a valuable tool for the development of novel anxiolytics. Given the limited available data, the generally low study quality and high heterogeneity additional studies are warranted to corroborate the findings of this review.

Neuroimaging Insights: Kava's (Piper methysticum) Effect on Dorsal Anterior Cingulate Cortex GABA in Generalized Anxiety Disorder

Generalised Anxiety Disorder (GAD) is a prevalent, chronic mental health disorder. The measurement of regional brain gamma-aminobutyric acid (GABA) offers insight into its role in anxiety and is a potential biomarker for treatment response. Research literature suggests Piper methysticum (Kava) is efficacious as an anxiety treatment, but no study has assessed its effects on central GABA levels. This study investigated dorsal anterior cingulate (dACC) GABA levels in 37 adult participants with GAD. GABA was measured using proton magnetic resonance spectroscopy (1H-MRS) at baseline and following an eight-week administration of Kava (standardised to 120 mg kavalactones twice daily) (n = 20) or placebo (n = 17). This study was part of the Kava for the Treatment of GAD (KGAD; ClinicalTrials.gov: NCT02219880), a 16-week intervention study. Compared with the placebo group, the Kava group had a significant reduction in dACC GABA (p = 0.049) at eight weeks. Baseline anxiety scores on the HAM-A were positively correlated with GABA levels but were not significantly related to treatment. Central GABA reductions following Kava treatment may signal an inhibitory effect, which, if considered efficacious, suggests that GABA levels are modulated by Kava, independent of reported anxiety symptoms. dACC GABA patterns suggest a functional role of higher levels in clinical anxiety but warrants further research for symptom benefit. Findings suggest that dACC GABA levels previously un-examined in GAD could serve as a biomarker for diagnosis and treatment response.

Changes in Adipokine, Resitin, and BDNF Concentrations in Treatment-Resistant Depression after Electroconvulsive Therapy

OBJECTIVES

One of the current challenges in psychiatry is the search for answers on how to effectively manage drug-resistant depression. The occurrence of drug resistance in patients is an indication for the use of electroconvulsive therapy (ECT). This method is highly effective and usually results in relatively quick health improvement. Despite the knowledge of how ECT works, not all of the biological pathways activated during its use have been identified. Hence, based on the neuroinflammatory hypothesis of depression, we investigated the concentration of two opposite-acting adipokines (anti-inflammatory adiponectin and proinflammatory resistin) and BDNF in antidepressant-resistant patients undergoing ECT.

METHODS

The study group comprised 52 patients hospitalized due to episodes of depression in the course of unipolar and bipolar affective disorder. The serum concentration of adipokines and BDNF was determined before and after the therapeutic intervention using an ELISA method. In the analyses, we also included comparisons considering the type of depression, sex, and achieving remission.

RESULTS

Adiponectin, resistin, and BDNF concentrations change after ECT treatment. These changes are correlated with an improvement in the severity of depressive symptoms and are more or less pronounced depending on the type of depression.

CONCLUSIONS

Although not all observed changes reach statistical significance, adipokines in particular remain exciting candidates for biomarkers in assessing the course of the disease and response to ECT treatment.

Voluntary wheel running during adolescence prevents the increase in ethanol intake induced by social defeat in male mice

RATIONALE

Exposure to social defeat (SD) induces a depressive phenotype, increased ethanol seeking and consumption, accompanied by activation of the neuroinflammatory response. However, a resilient response can be potentiated through physical exercise in the form of voluntary wheel running (VWR) during or after exposure to social stress. Therefore, the aim of this study was to test whether physical exercise during adolescence prior to being exposed to SD can enhance resilience to the increase in ethanol intake.

METHODS

Male mice had access to VWR during adolescence and the effects of social defeat (4 sessions every 72 h) on oral ethanol self-administration (SA) was evaluated. Based on the social interaction test, mice were classified as resilient or susceptible to depressive-like behavior. Two weeks after the last encounter, mice were subjected to the drinking in the dark and oral ethanol SA paradigms. Mice were then sacrificed to measure brain-derived neurotrophic factor (BDNF) levels in the striatum and hippocampus.

RESULTS

As expected, susceptible mice increased ethanol intake in the oral SA protocol. However, susceptible mice in the exercise condition did not increase ethanol intake, showing similar consumption and motivation for ethanol than the control and resilient groups. On the other hand, decreased BDNF levels were observed in susceptible mice in both experimental conditions compared to the control groups after ethanol SA.

CONCLUSIONS

The pre-exposure of VWR prevented the increase in consumption and motivation for ethanol induced by SD in susceptible mice. On the other hand, it appears that VWR did not exhibit any significant long-term effects on BDNF signaling, which is mainly affected in susceptible mice after ethanol intake.

11-Ethoxyviburtinal improves chronic restraint stress-induced anxiety-like behaviors in gender-specific mice via PI3K/Akt and E2 /ERβ signaling pathways

Anxiety disorder is a chronic and disabling psychiatric disorder that is more prevalent in females than in males. 11-Ethoxyviburtinal is an iridoid extracted from Valeriana jatamansi Jones, which has anxiolytic potential. The aim of the present work was to study the anxiolytic efficacy and mechanism of 11-ethoxyviburtinal in gender-specific mice. We first evaluated the anxiolytic-like efficacy of 11-ethoxyviburtinal in chronic restraint stress (CRS) mice of different sexes through behavioral experiments and biochemical indexes. In addition, network pharmacology and molecular docking were used to predict potential targets and important pathways for the treatment of anxiety disorder with 11-ethoxyviburtinal. Finally, the influence of 11-ethoxyviburtinal on phosphoinositide-3-kinase (PI3K)/protein kinase B (Akt) signaling pathway, estrogen receptor β (ERβ) expression, and anxiety-like behavior in mice was verified by western blotting, immunohistochemistry staining, antagonist intervention methods, and behavioral experiments. 11-ethoxyviburtinal alleviated the anxiety-like behaviors induced by CRS and inhibited neurotransmitter dysregulation and HPA axis hyperactivity. It inhibited the abnormal activation of the PI3K/Akt signaling pathway, modulated estrogen production, and promoted ERβ expression in mice. In addition, the female mice may be more sensitive to the pharmacological effects of 11-ethoxyviburtinal. 11-ethoxyviburtinal may exert its anxiolytic-like effects through PI3K/Akt and E2/ERβ signaling pathways. Meanwhile, by comparing the male and female mice, gender differences may affect the therapy and development of anxiety disorder.

Chronic social comparison elicits depression- and anxiety-like behaviors and alterations in brain-derived neurotrophic factor expression in male rats

Social comparison is a fundamental human characteristic; however, long-term social comparison may induce psychological stress and can lead to depression and anxiety. Recent studies have shown that nonhuman primates compare themselves with others; however, no studies have investigated whether social comparisons exist among rodents. In the present study, we established a rat model of social comparison. This model was subsequently used to examine the effects of the differential environment of a partner on depression- and anxiety-like behaviors in male rats, as well as to assess the changes in serum, medial prefrontal cortex (mPFC), and dorsal hippocampus brain-derived neurotrophic factor (BDNF) levels induced by long-term social comparison. Compared to rats whose partners were exposed to the same environment, rats whose partners were exposed to two combined enriched environmental stimuli for 14 days showed significantly decreased social novelty preference and sucrose consumption. No anxiety-like behaviors were observed. Rats whose partners were exposed to one enriched environment for 31 days showed significantly increased immobility time in the forced swimming test, and significantly decreased time spent in the center area in the open-field test. Further, rats whose partners were exposed to one enriched environment for 31 days showed lower BDNF levels in the mPFC and dorsal hippocampus, but not following partner exposure for 14 days. These results suggest that social comparisons exist in rats and can induce psychosocial stress and other negative affect. This model will not only provide the possibility to reveal the neurobiological basis of the emotional impact of social comparison, but could also be used to confirm the conservative evolutionary characteristics of social comparison as a behavioral attribute.

The Neurobiological Underpinnings of Obsessive-Compulsive Symptoms in Psychosis, Translational Issues for Treatment-Resistant Schizophrenia

Almost 25% of schizophrenia patients suffer from obsessive-compulsive symptoms (OCS) considered a transdiagnostic clinical continuum. The presence of symptoms pertaining to both schizophrenia and obsessive-compulsive disorder (OCD) may complicate pharmacological treatment and could contribute to lack or poor response to the therapy. Despite the clinical relevance, no reviews have been recently published on the possible neurobiological underpinnings of this comorbidity, which is still unclear. An integrative view exploring this topic should take into account the following aspects: (i) the implication for glutamate, dopamine, and serotonin neurotransmission as demonstrated by genetic findings; (ii) the growing neuroimaging evidence of the common brain regions and dysfunctional circuits involved in both diseases; (iii) the pharmacological modulation of dopaminergic, serotoninergic, and glutamatergic systems as current therapeutic strategies in schizophrenia OCS; (iv) the recent discovery of midbrain dopamine neurons and dopamine D1- and D2-like receptors as orchestrating hubs in repetitive and psychotic behaviors; (v) the contribution of N-methyl-D-aspartate receptor subunits to both psychosis and OCD neurobiology. Finally, we discuss the potential role of the postsynaptic density as a structural and functional hub for multiple molecular signaling both in schizophrenia and OCD pathophysiology.

Reversal of the detrimental effects of social isolation on ischemic cerebral injury and stroke-associated pneumonia by inhibiting small intestinal T-cell migration into the brain and lung

Social isolation (ISO) is associated with an increased risk and poor outcomes of ischemic stroke. However, the roles and mechanisms of ISO in stroke-associated pneumonia (SAP) remain unclear. Adult male mice were single- or pair-housed with an ovariectomized female mouse and then subjected to transient middle cerebral artery occlusion. Isolated mice were treated with the natriuretic peptide receptor A antagonist A71915 or anti-gamma-delta (γδ) TCR monoclonal antibody, whereas pair-housed mice were treated with recombinant human atrial natriuretic peptide (rhANP). Subdiaphragmatic vagotomy (SDV) was performed 14 days before single- or pair-housed conditions. We found that ISO significantly worsened brain and lung injuries relative to pair housing, which was partially mediated by elevated interleukin (IL)-17A levels and the migration of small intestine-derived inflammatory γδ T-cells into the brain and lung. However, rhANP treatment or SDV could ameliorate ISO-exacerbated post-stroke brain and lung damage by reducing IL-17A levels and inhibiting the migration of inflammatory γδ T-cells into the brain and lung. Our results suggest that rhANP mitigated ISO-induced exacerbation of SAP and ischemic cerebral injury by inhibiting small intestine-derived γδ T-cell migration into the lung and brain, which could be mediated by the subdiaphragmatic vagus nerve.

EPD1504: a novel μ-opioid receptor partial agonist attenuates obsessive-compulsive disorder (OCD)-like behaviors

Low doses of μ-opioid receptor (MOR) agonists rapidly ameliorate symptoms in treatment-resistant obsessive-compulsive disorder (OCD) patients (10-50% of OCD patients). However, the utility of MOR agonists is limited by their safety liabilities. We developed a novel MOR partial agonist (EPD1540) that has an improved respiratory safety profile when compared to buprenorphine. Buprenorphine is a MOR partial agonist primarily used in the treatment of opiate-use disorder, which in investigator-led trials, has been shown to rapidly ameliorate symptoms in treatment-resistant OCD patients. In this study, we show that doses of EPD1504 and buprenorphine that occupy small fractions of MORs in the CNS (approximately 20%) are as effective as fluoxetine at ameliorating OCD-like behaviors in two different rat models (an operant probabilistic reversal task and marble burying). Importantly, effective doses of EPD1504 did not impair either locomotor activity, or respiration under normoxic or hypercapnic conditions. Additionally, EPD1504 had effects comparable to buprenorphine in the conditioned place preference assay. These results indicate that EPD1504 may provide a safer alternative to buprenorphine for the treatment of OCD patients.

Candidate biomarkers in psychiatric disorders: state of the field

The field of psychiatry is hampered by a lack of robust, reliable and valid biomarkers that can aid in objectively diagnosing patients and providing individualized treatment recommendations. Here we review and critically evaluate the evidence for the most promising biomarkers in the psychiatric neuroscience literature for autism spectrum disorder, schizophrenia, anxiety disorders and post-traumatic stress disorder, major depression and bipolar disorder, and substance use disorders. Candidate biomarkers reviewed include various neuroimaging, genetic, molecular and peripheral assays, for the purposes of determining susceptibility or presence of illness, and predicting treatment response or safety. This review highlights a critical gap in the biomarker validation process. An enormous societal investment over the past 50 years has identified numerous candidate biomarkers. However, to date, the overwhelming majority of these measures have not been proven sufficiently reliable, valid and useful to be adopted clinically. It is time to consider whether strategic investments might break this impasse, focusing on a limited number of promising candidates to advance through a process of definitive testing for a specific indication. Some promising candidates for definitive testing include the N170 signal, an event-related brain potential measured using electroencephalography, for subgroup identification within autism spectrum disorder; striatal resting-state functional magnetic resonance imaging (fMRI) measures, such as the striatal connectivity index (SCI) and the functional striatal abnormalities (FSA) index, for prediction of treatment response in schizophrenia; error-related negativity (ERN), an electrophysiological index, for prediction of first onset of generalized anxiety disorder, and resting-state and structural brain connectomic measures for prediction of treatment response in social anxiety disorder. Alternate forms of classification may be useful for conceptualizing and testing potential biomarkers. Collaborative efforts allowing the inclusion of biosystems beyond genetics and neuroimaging are needed, and online remote acquisition of selected measures in a naturalistic setting using mobile health tools may significantly advance the field. Setting specific benchmarks for well-defined target application, along with development of appropriate funding and partnership mechanisms, would also be crucial. Finally, it should never be forgotten that, for a biomarker to be actionable, it will need to be clinically predictive at the individual level and viable in clinical settings.

Hair cortisol, cortisone and DHEA concentrations and the composition of microbiota in toddlers

Animal research suggests that the gut microbiota and the HPA axis communicate in a bidirectional manner. However, human data, especially on early childhood, remain limited. In this exploratory design, we investigated the connections between long-term HPA axis functioning, measured as cortisol, cortisone or dehydroepiandrosterone concentrations and their ratios from hair segments of three centimeters, and gut microbiota profiles, (measured as diversity and bacterial composition by 16 S rRNA sequencing) in healthy 2.5-year-old toddlers (n = 135) recruited from the FinnBrain Birth Cohort Study. The alpha diversity of the microbiota was studied by linear regression. Beta diversity analyses with weighted UniFrac or Bray-Curtis distances were performed using PERMANOVA. The bacterial core genus level analyses were conducted using DESeq2 and ALDEx2. These analyses suggested that hair sample concentrations of separate hormones, cortisol/cortisone and cortisol/dehydroepiandrosterone ratios were associated with various gut bacterial genera such as the Veillonella, the [Ruminococcus] torques group and [Eubacterium] hallii group, although multiple testing correction attenuated the p-values. Alpha or beta diversity was not linked with either steroid concentrations or ratios. These findings in toddlers suggest that long-term HPA axis activity may be related to genera abundancies but not to ecosystem-level measures in gut microbiota. The influence of these observed interrelations on later child health and development warrants further research.

High treatment resistance is associated with lower performance in the Stroop test in patients with obsessive-compulsive disorder

Around 50% of the patients with obsessive-compulsive disorder (OCD) are resistant to treatment, and patients with OCD show alterations in a broad range of cognitive abilities. The present study investigated the links between treatment-resistance, executive and working memory abilities, and the severity of OCD symptoms among 66 patients with OCD. The patients performed seven tests gauging their executive functions and working memory and filled in questionnaires for OCD severity and insight into their pathology. In addition, the executive and working memory abilities of a subset of these patients were compared with those of individually matched control participants. In contrast with previous studies, patients' treatment resistance was evaluated by considering the clinical outcomes of all the treatments that they received during the course of their disease. Higher treatment resistance was associated with lower performance in one particular executive test, the Stroop test, which assessed patients' ability to inhibit prepotent/automatic responses. Older age and more severe OCD symptoms were also associated with higher treatment resistance. Regardless of OCD severity, the patients displayed small to moderate deficits across most components of executive functions compared to control participants. Interestingly, patients with OCD took more time than control participants to perform speeded neuropsychological tests but never made more errors. Altogether, this study shows that the treatment-resistance of patients with OCD may be reliably quantified over the course of years and treatments using Pallanti and Quercioli's (2006) treatment resistance-related scales. The data suggest that the Stroop test could be used clinically to anticipate treatment outcomes in to-be-treated patients.

Aged brain and neuroimmune responses to COVID-19: post-acute sequelae and modulatory effects of behavioral and nutritional interventions

Advanced age is one of the significant risk determinants for coronavirus disease 2019 (COVID-19)-related mortality and for long COVID complications. The contributing factors may include the age-related dynamical remodeling of the immune system, known as immunosenescence and chronic low-grade systemic inflammation. Both of these factors may induce an inflammatory milieu in the aged brain and drive the changes in the microenvironment of neurons and microglia, which are characterized by a general condition of chronic inflammation, so-called neuroinflammation. Emerging evidence reveals that the immune privilege in the aging brain may be compromised. Resident brain cells, such as astrocytes, neurons, oligodendrocytes and microglia, but also infiltrating immune cells, such as monocytes, T cells and macrophages participate in the complex intercellular networks and multiple reciprocal interactions. Especially changes in microglia playing a regulatory role in inflammation, contribute to disturbing of the brain homeostasis and to impairments of the neuroimmune responses. Neuroinflammation may trigger structural damage, diminish regeneration, induce neuronal cell death, modulate synaptic remodeling and in this manner negatively interfere with the brain functions.In this review article, we give insights into neuroimmune interactions in the aged brain and highlight the impact of COVID-19 on the functional systems already modulated by immunosenescence and neuroinflammation. We discuss the potential ways of these interactions with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and review proposed neuroimmune mechanisms and biological factors that may contribute to the development of persisting long COVID conditions. We summarize the potential mechanisms responsible for long COVID, including inflammation, autoimmunity, direct virus-mediated cytotoxicity, hypercoagulation, mitochondrial failure, dysbiosis, and the reactivation of other persisting viruses, such as the Cytomegalovirus (CMV). Finally, we discuss the effects of various interventional options that can decrease the propagation of biological, physiological, and psychosocial stressors that are responsible for neuroimmune activation and which may inhibit the triggering of unbalanced inflammatory responses. We highlight the modulatory effects of bioactive nutritional compounds along with the multimodal benefits of behavioral interventions and moderate exercise, which can be applied as postinfectious interventions in order to improve brain health.

Acute administration of a dopamine D2/D3 receptor agonist alters behavioral and neural parameters in adult zebrafish

The dopaminergic neurotransmitter system is implicated in several brain functions and behavioral processes. Alterations in it are associated with the pathogenesis of several human neurological disorders. Pharmacological agents that interact with the dopaminergic system allow the investigation of dopamine-mediated cellular and molecular responses and may elucidate the biological bases of such disorders. Zebrafish, a translationally relevant biomedical research organism, has been successfully employed in prior psychopharmacology studies. Here, we evaluated the effects of quinpirole (dopamine D2/D3 receptor agonist) in adult zebrafish on behavioral parameters, brain-derived neurotrophic factor (BDNF) and neurotransmitter levels. Zebrafish received intraperitoneal injections of 0.5, 1.0, or 2.0 mg/kg quinpirole or saline (control group) twice with an inter-injection interval of 48 h. All tests were performed 24 h after the second injection. After this acute quinpirole administration, zebrafish exhibited decreased locomotor activity, increased anxiety-like behaviors and memory impairment. However, quinpirole did not affect social and aggressive behavior. Quinpirole-treated fish exhibited stereotypic swimming, characterized by repetitive behavior followed by immobile episodes. Moreover, quinpirole treatment also decreased the number of BDNF-immunoreactive cells in the zebrafish brain. Analysis of neurotransmitter levels demonstrated a significant increase in glutamate and a decrease in serotonin, while no alterations were observed in dopamine. These findings demonstrate that dopaminergic signaling altered by quinpirole administration results in significant behavioral and neuroplastic changes in the central nervous system of zebrafish. Thus, we conclude that the use of quinpirole administration in adult zebrafish may be an appropriate tool for the analysis of mechanisms underlying neurological disorders related to the dopaminergic system.

Mind-Body Intervention for Dysfunctional Breathing in Chronic Obstructive Pulmonary Disease: Feasibility Study and Lessons Learned

Purpose: Dysfunctional breathing behaviors are prevalent in chronic obstructive pulmonary disease (COPD). Although these behaviors contribute to dyspnea, abnormal carbon dioxide (CO2) levels, and COPD exacerbations, they are modifiable. Current dyspnea treatments for COPD are suboptimal, because they do not adequately address dysfunctional breathing behaviors and anxiety together. We developed a complementary mind-body breathlessness therapy, called capnography-assisted respiratory therapy (CART), that uses real-time CO2 biofeedback at the end of exhalation (end-tidal CO2 or ETCO2), to target dysfunctional breathing habits and improve dyspnea treatment and pulmonary rehabilitation (PR) adherence in COPD. The study aim was to test the feasibility of integrating CART with a traditional, clinic-based PR program in an urban setting. Methods: We used a feasibility pre- and post-test design, with 2:1 randomization to CART+PR or control (PR-alone) groups, to test and refine CART. Multi-component CART consisted of six, 1-h weekly sessions of slow breathing and mindfulness exercises, ETCO2 biofeedback, motivational counseling, and a home program. All participants were offered twice weekly, 1-h sessions of PR over 10 weeks (up to 20 sessions). Results: Thirty-one participants with COPD were enrolled in the study. Approximately a third of participants had symptoms of psychological distress. Results showed that CART was feasible and acceptable based on 74% session completion and 91.7% homework exercise completion (n = 22). Within-group effect sizes for CART+PR were moderate to large (Cohen's d = 0.51-1.22) for reduction in resting Borg dyspnea (anticipatory anxiety) and respiratory rate, St. George's Respiratory Questionnaire (SGRQ) respiratory symptoms; and increase in Patient-Reported Outcomes Measurement Information System (PROMIS) physical function and physical activity; all p < 0.05. Conclusions: CART is a new mind-body breathing therapy that targets eucapnic breathing, interoceptive function, and self-regulated breathing to relieve dyspnea and anxiety symptoms in COPD. Study findings supported the feasibility of CART and showed preliminary signals that CART may improve exercise tolerance, reduce dyspnea, and enhance PR completion by targeting reduced dysfunctional breathing patterns (CTR No. NCT03457103).

New and emerging approaches to treat psychiatric disorders

Psychiatric disorders are highly prevalent, often devastating diseases that negatively impact the lives of millions of people worldwide. Although their etiological and diagnostic heterogeneity has long challenged drug discovery, an emerging circuit-based understanding of psychiatric illness is offering an important alternative to the current reliance on trial and error, both in the development and in the clinical application of treatments. Here we review new and emerging treatment approaches, with a particular emphasis on the revolutionary potential of brain-circuit-based interventions for precision psychiatry. Limitations of circuit models, challenges of bringing precision therapeutics to market and the crucial advances needed to overcome these obstacles are presented.

World Federation of Societies of Biological Psychiatry (WFSBP) guidelines for treatment of anxiety, obsessive-compulsive and posttraumatic stress disorders - Version 3. Part I: Anxiety disorders

AIM

This is the third version of the guideline of the World Federation of Societies of Biological Psychiatry (WFSBP) Task Force for the Pharmacological Treatment of Anxiety, Obsessive-Compulsive and Posttraumatic Stress Disorders (published in 2002, revised in 2008).

METHOD

A consensus panel of 33 international experts representing 22 countries developed recommendations based on efficacy and acceptability of available treatments. In total, 1007 RCTs for the treatment of these disorders in adults, adolescents, and children with medications, psychotherapy and other non-pharmacological interventions were evaluated, applying the same rigorous methods that are standard for the assessment of medications.

RESULT

This paper, Part I, contains recommendations for the treatment of panic disorder/agoraphobia (PDA), generalised anxiety disorder (GAD), social anxiety disorder (SAD), specific phobias, mixed anxiety disorders in children and adolescents, separation anxiety and selective mutism. Selective serotonin reuptake inhibitors (SSRI) and serotonin-norepinephrine reuptake inhibitors (SNRIs) are first-line medications. Cognitive behavioural therapy (CBT) is the first-line psychotherapy for anxiety disorders. The expert panel also made recommendations for patients not responding to standard treatments and recommendations against interventions with insufficient evidence.

CONCLUSION

It is the goal of this initiative to provide treatment guidance for these disorders that has validity throughout the world.

World Federation of Societies of Biological Psychiatry (WFSBP) guidelines for treatment of anxiety, obsessive-compulsive and posttraumatic stress disorders - Version 3. Part II: OCD and PTSD

AIM

This is the third version of the guideline of the World Federation of Societies of Biological Psychiatry (WFSBP) Task Force for the Pharmacological Treatment of Anxiety, Obsessive-Compulsive and Posttraumatic Stress Disorders which was published in 2002 and revised in 2008.

METHOD

A consensus panel of 34 international experts representing 22 countries developed recommendations based on efficacy and acceptability of the treatments. In this version, not only medications but also psychotherapies and other non-pharmacological interventions were evaluated, applying the same rigorous methods that are standard for the assessment of medication treatments.

RESULT

The present paper (Part II) contains recommendations based on published randomised controlled trials (RCTs) for the treatment of OCD (n = 291) and PTSD (n = 234) in children, adolescents, and adults. The accompanying paper (Part I) contains the recommendations for the treatment of anxiety disorders.For OCD, first-line treatments are selective serotonin reuptake inhibitors (SSRIs) and cognitive behavioural therapy (CBT). Internet-CBT was also superior to active controls. Several second-line medications are available, including clomipramine. For treatment-resistant cases, several options are available, including augmentation of SSRI treatment with antipsychotics and other drugs.Other non-pharmacological treatments, including repetitive transcranial magnetic stimulation (rTMS), deep brain stimulation (DBS) and others were also evaluated.For PTSD, SSRIs and the SNRI venlafaxine are first-line treatments. CBT is the psychotherapy modality with the best body of evidence. For treatment-unresponsive patients, augmentation of SSRI treatment with antipsychotics may be an option.

CONCLUSION

OCD and PTSD can be effectively treated with CBT and medications.

Candidate Biological Markers for Social Anxiety Disorder: A Systematic Review

Social anxiety disorder (SAD) is a common psychiatric condition associated with a high risk of psychiatric comorbidity and impaired social/occupational functioning when not promptly treated. The identification of biological markers may facilitate the diagnostic process, leading to an early and proper treatment. Our aim was to systematically review the available literature about potential biomarkers for SAD. A search in the main online repositories (PubMed, ISI Web of Knowledge, PsychInfo, etc.) was performed. Of the 662 records screened, 61 were included. Results concerning cortisol, neuropeptides and inflammatory/immunological/neurotrophic markers remain inconsistent. Preliminary evidence emerged about the role of chromosome 16 and the endomannosidase gene, as well as of epigenetic factors, in increasing vulnerability to SAD. Neuroimaging findings revealed an altered connectivity of different cerebral areas in SAD patients and amygdala activation under social threat. Some parameters such as salivary alpha amylase levels, changes in antioxidant defenses, increased gaze avoidance and QT dispersion seem to be associated with SAD and may represent promising biomarkers of this condition. However, the preliminary positive correlations have been poorly replicated. Further studies on larger samples and investigating the same biomarkers are needed to identify more specific biological markers for SAD.

Salivary Antioxidant Capacity and Magnesium in Generalized Anxiety Disorder

Generalized anxiety disorder (GAD) is a prevalent disorder. The search for biomarkers may contribute to new knowledge about molecular pathogenesis and treatment. Since oxidative stress and micronutrient imbalance play a key role in the development of mental disorders, we aimed to study salivary antioxidant capacity and magnesium in patients with GAD in an anxiety model of solving problems with increasing complexity. The study subgroup consisted of 15 patients with GAD, and 17 healthy volunteers of the same age made up the control subgroup. Participants took a test with six levels of difficulty, which included false feedback. In this test, the participants were asked to remember the colors of balloons and react when the color changed. The reaction time, the number of correct answers, as well as biochemical parameters such as the antioxidant capacity of saliva and salivary magnesium, were assessed. There was no difference in the results of the quest between the subgroups; however, anxious participants spent more time at the moment of experimental frustration due to incorrect feedback and additional negative psycho-emotional load. Antioxidant capacity did not differ between the subgroups both before and after the experimental session. Average antioxidant capacity also did not change significantly at the endpoint of the experiment. However, the endpoint antioxidant capacity correlated negatively with the reaction time in anxious patients in the second block (where the false feedback as a frustrating factor appeared). Magnesium was initially significantly higher in the group of anxious participants and decreased at the experiment endpoint; in healthy patients, there were no changes in salivary magnesium at the endpoint. In conclusion, the compensatory potential of oxidative metabolism and magnesium in patients with GAD was spent with additional psycho-emotional stress, in contrast to healthy individuals, but it was sufficient to avoid exhaustion during experimental frustrating exposure.

Sex Differences in Depression and Anxiety

Depression and anxiety disorders carry a tremendous worldwide burden and emerge as a significant cause of disability among western societies. Both disorders are known to disproportionally affect women, as they are twice more likely to be diagnosed and moreover, they are also prone to suffer from female-specific mood disorders. Importantly, the prevalence of these affective disorders has notably risen after the COVID pandemic, especially in women. In this chapter, we describe factors that are possibly contributing to the expression of such sex differences in depression and anxiety. For this, we overview the effect of transcriptomic and genetic factors, the immune system, neuroendocrine aspects, and cognition. Furthermore, we also provide evidence of sex differences in antidepressant response and their causes. Finally, we emphasize the importance to consider sex as a biological variable in preclinical and clinical research, which may facilitate the discovery and development of new and more efficacious antidepressant and anxiolytic pharmacotherapies for both women and men.

The price of love: an investigation into the relationship between romantic love and the expression of obsessive-compulsive disorder

BACKGROUND

The present study explored the influence of romantic love on the expression of several obsessive-compulsive disorder (OCD) characteristics, including symptom severity, symptom dimensions, age at onset, sensory phenomena (SP), and developmental course, as well as other related comorbid disorders. It was hypothesized that love-precipitated OCD would be associated with a set of distinct characteristics and exhibit greater rates of comorbid disorders.

METHODS

The analyses were performed using a large sample (n = 981) of clinical patients with a primary diagnosis of OCD (Females = 67.3%, M age = 35.31).

RESULTS

Love-precipitated OCD was associated with greater severity of SP and later age at onset of obsessions. However, symptom severity, symptom dimension, developmental course, and psychiatric comorbidities were not associated with love-precipitated OCD.

CONCLUSION

It was concluded that romantic love does shape the expression of OCD, especially with regard to SP and onset age. These findings encourage further exploration to determine its clinical significance as a phenotype.

Social Anxiety Disorder: Associated Conditions and Therapeutic Approaches

Social anxiety disorder (SAD) is a highly distressing chronic psychiatric disorder characterized by persistent fear of social situations in anticipation of being judged negatively by others. As shyness mimics some of the symptoms of SAD, people suffering from this debilitating disease are often underdiagnosed. It can have a devastating impact on all areas of life including academic performance, social growth, relationship status, and work performance. In recent years, research on anxiety and related disorders has proliferated due to the increased use of cognitive-behavioral models. The understanding of SAD has evolved greatly from distinguishing it from shyness to implementing modalities to comprehend the sophisticated underlying mechanism of disease prevalence and progression as well as methods to treat it. This review summarizes the concept of SAD, its epidemiology, symptoms, and diagnostic tools. Frequent comorbidities including other psychiatric disorders are also discussed. Additionally, we examine the latest evidence related to treatment options including psychotherapy and pharmacotherapy as well as recommendations for managing SAD.

The Anxiolytic Activity of Schinus terebinthifolia Leaf Lectin (SteLL) Is Dependent on Monoaminergic Signaling although Independent of the Carbohydrate-Binding Domain of the Lectin

The potential of plant lectins (carbohydrate-binding proteins) for the treatment of neurological disorders such as anxiety and depression has started to be reported in the last few years. Schinus terebinthifolia leaves contain a lectin called SteLL, which has displayed antimicrobial, immunomodulatory, antitumor, and analgesic activities. However, the effects of SteLL on the Central Nervous System (CNS) have not yet been determined. In this study, we investigated the in vivo anxiolytic effect of SteLL in mice using the open field (OF) and elevated plus maze (EPM) tests. In the OF, SteLL (1, 2, and 4 mg/kg, i.p.) did not interfere with the number of crossings but significantly reduced the number of rearings. In the EPM, SteLL 4 mg/kg and the combination SteLL (1 mg/kg) plus diazepam (1 mg/kg) significantly increased the time spent in the open arms while reducing the time spent in the closed arms. The anxiolytic effect of SteLL did not seem to be dependent on the carbohydrate-binding domain of the lectin. Nevertheless, the SteLL effect in the EPM was reversed by the pretreatment with the pharmacological antagonists of the α2-adrenoceptor, 5-HT2A/2C serotonin receptor, and the D1 dopamine receptor. Overall, our results suggest that the anxiolytic effect of SteLL is dependent on the monoaminergic signaling cascade.

Advances in problematic usage of the internet research - A narrative review by experts from the European network for problematic usage of the internet

Global concern about problematic usage of the internet (PUI), and its public health and societal costs, continues to grow, sharpened in focus under the privations of the COVID-19 pandemic. This narrative review reports the expert opinions of members of the largest international network of researchers on PUI in the framework of the European Cooperation in Science and Technology (COST) Action (CA 16207), on the scientific progress made and the critical knowledge gaps remaining to be filled as the term of the Action reaches its conclusion. A key advance has been achieving consensus on the clinical definition of various forms of PUI. Based on the overarching public health principles of protecting individuals and the public from harm and promoting the highest attainable standard of health, the World Health Organisation has introduced several new structured diagnoses into the ICD-11, including gambling disorder, gaming disorder, compulsive sexual behaviour disorder, and other unspecified or specified disorders due to addictive behaviours, alongside naming online activity as a diagnostic specifier. These definitions provide for the first time a sound platform for developing systematic networked research into various forms of PUI at global scale. Progress has also been made in areas such as refining and simplifying some of the available assessment instruments, clarifying the underpinning brain-based and social determinants, and building more empirically based etiological models, as a basis for therapeutic intervention, alongside public engagement initiatives. However, important gaps in our knowledge remain to be tackled. Principal among these include a better understanding of the course and evolution of the PUI-related problems, across different age groups, genders and other specific vulnerable groups, reliable methods for early identification of individuals at risk (before PUI becomes disordered), efficacious preventative and therapeutic interventions and ethical health and social policy changes that adequately safeguard human digital rights. The paper concludes with recommendations for achievable research goals, based on longitudinal analysis of a large multinational cohort co-designed with public stakeholders.

Animal Behavior in Psychedelic Research

Psychedelic-assisted psychotherapy holds great promise in the treatment of mental health disorders. Research into 5-hydroxytryptamine 2A receptor (5-HT_2AR) agonist psychedelic compounds has increased dramatically over the past two decades. In humans, these compounds produce drastic effects on consciousness, and their therapeutic potential relates to changes in the processing of emotional, social, and self-referential information. The use of animal behavior to study psychedelics is under debate, and this review provides a critical perspective on the translational value of animal behavior studies in psychedelic research. Acute activation of 5-HT_2ARs produces head twitches and unique discriminative cues, disrupts sensorimotor gating, and stimulates motor activity while inhibiting exploration in rodents. The acute treatment with psychedelics shows discrepant results in conventional rodent tests of depression-like behaviors but generally induces anxiolytic-like effects and inhibits repetitive behavior in rodents. Psychedelics impair waiting impulsivity but show discrepant effects in other tests of cognitive function. Tests of social interaction also show conflicting results. Effects on measures of time perception depend on the experimental schedule. Lasting or delayed effects of psychedelics in rodent tests related to different behavioral domains appear to be rather sensitive to changes in experimental protocols. Studying the effects of psychedelics on animal behaviors of relevance to effects on psychiatric symptoms in humans, assessing lasting effects, publishing negative findings, and relating behaviors in rodents and humans to other more translatable readouts, such as neuroplastic changes, will improve the translational value of animal behavioral studies in psychedelic research. SIGNIFICANCE STATEMENT: Psychedelics like LSD and psilocybin have received immense interest as potential new treatments of psychiatric disorders. Psychedelics change high-order consciousness in humans, and there is debate about the use of animal behavior studies to investigate these compounds. This review provides an overview of the behavioral effects of 5-HT_2AR agonist psychedelics in laboratory animals and discusses the translatability of the effects in animals to effects in humans. Possible ways to improve the utility of animal behavior in psychedelic research are discussed.

Salivary Biomarkers Associated with Psychological Alterations in Patients with Diabetes: A Systematic Review

The care of individuals with diabetes needs a holistic perspective, taking into account both the physical disease and the mental health problems that may be associated. Different studies show a higher prevalence of depression or anxiety issues in diabetes patients than in the general population, which is why diabetes can be considered one of the chronic diseases in which psychological care is crucial to maintain quality of life. The objective of this review is to examine the published articles that relate the bidirectional associations between objective and subjective measures of anxiety, depressive symptomatology, stress, sleep quality, and salivary biomarkers in patients with diabetes. For this, a search was carried out in the electronic databases PubMed, Cochrane, and SCOPUS using the keywords "diabetes", "saliva", "sleep", "anxiety", "depression", and "stress" for works published up until May 2022 and limited to the English and Spanish languages. The sample comprised 14 articles, 5 of which analysed the associations between depressive symptomatology and salivary biomarkers in people with diabetes. Among the salivary biomarkers most frequently used to evaluate psychological alterations in persons with diabetes are cortisol and melatonin. Thus, significant changes in the levels of these biomarkers were observed in most studies. Four out of five studies reported a statistically significant relationship between increased salivary cortisol in the evening/midnight or the cortisol awakening response and depressive symptoms. In contrast, lower cortisol levels upon waking in the morning were observed when there was no depression or anxiety. Regarding the association between salivary cortisol values and sleep quality in patients with diabetes, lower morning cortisol values related to prolonged nighttime sleep were common in the analysed studies. Low melatonin concentrations showed a negative correlation with sleep quality. As it is an easy-to-apply and non-invasive method, the measurement of salivary biomarkers can be very useful for predicting psychological alterations in patients with diabetes. Further scientific studies are required to determine the sensitivity of these biological substances acting as biomarkers for detecting sleep disorders and psychological alterations.

A High-Sugar Diet Consumption, Metabolism and Health Impacts with a Focus on the Development of Substance Use Disorder: A Narrative Review

Carbohydrates are important macronutrients in human and rodent diet patterns that play a key role in crucial metabolic pathways and provide the necessary energy for proper body functioning. Sugar homeostasis and intake require complex hormonal and nervous control to proper body energy balance. Added sugar in processed food results in metabolic, cardiovascular, and nervous disorders. Epidemiological reports have shown enhanced consumption of sweet products in children and adults, especially in reproductive age and in pregnant women, which can lead to the susceptibility of offspring’s health to diseases in early life or in adulthood and proneness to mental disorders. In this review, we discuss the impacts of high-sugar diet (HSD) or sugar intake during the perinatal and/or postnatal periods on neural and behavioural disturbances as well as on the development of substance use disorder (SUD). Since several emotional behavioural disturbances are recognized as predictors of SUD, we also present how HSD enhances impulsive behaviour, stress, anxiety and depression. Apart from the influence of HSD on these mood disturbances, added sugar can render food addiction. Both food and addictive substances change the sensitivity of the brain rewarding neurotransmission signalling. The results of the collected studies could be important in assessing sugar intake, especially via maternal dietary patterns, from the clinical perspective of SUD prevention or pre-existing emotional disorders. Methodology: This narrative review focuses on the roles of a high-sugar diet (HSD) and added sugar in foods and on the impacts of glucose and fructose on the development of substance use disorder (SUD) and on the behavioural predictors of drugs abuse. The literature was reviewed by two authors independently according to the topic of the review. We searched the PubMed and Scopus databases and Multidisciplinary Digital Publishing Institute open access scientific journals using the following keyword search strategy depending on the theme of the chapter: “high-sugar diet” OR “high-carbohydrate diet” OR “sugar” OR “glucose” OR “fructose” OR “added sugar” AND keywords. We excluded inaccessible or pay-walled articles, abstracts, conference papers, editorials, letters, commentary, and short notes. Reviews, experimental studies, and epidemiological data, published since 1990s, were searched and collected depending on the chapter structure. After the search, all duplicates are thrown out and full texts were read, and findings were rescreened. After the selection process, appropriate papers were included to present in this review.

Progress in Personalized Psychiatric Therapy with the Example of Using Intranasal Oxytocin in PTSD Treatment

Post-traumatic stress disorder (PTSD) is a severe mental disorder that results in the frequent coexistence of other diseases, lowers patients’ quality of life, and has a high annual cost of treatment. However, despite the variety of therapeutic approaches that exist, some patients still do not achieve the desired results. In addition, we may soon face an increase in the number of new PTSD cases because of the current global situation—both the COVID-19 pandemic and the ongoing armed conflicts. Hence, in recent years, many publications have sought a new, more personalized treatment approach. One such approach is the administration of intranasal oxytocin (INOXT), which, due to its pleiotropic effects, seems to be a promising therapeutic option. However, the current findings suggest that it might only be helpful for a limited, strictly selected group of patients.

A Diet Supplemented with Polyphenols, Prebiotics and Omega-3 Fatty Acids Modulates the Intestinal Microbiota and Improves the Profile of Metabolites Linked with Anxiety in Dogs

Simple Summary

This study used a nutrition-based approach to examine the effects of foods supplemented with fish oil and a polyphenol blend (citrus pulp, carrot, and spinach) with or without added tomato pomace on anxiety-related biomarkers in dogs. First, all dogs consumed the same initial food, then either the control or test (with tomato pomace) foods, then the washout food, then switched over to the test or control foods, each for 30-day periods. Many more changes in plasma and fecal metabolites were observed when comparing the washout food with the control or test foods than when the control and test foods were compared. Plasma levels of several metabolites that were previously associated with anxiety disorders, including 4-ethylphenyl sulfate, were decreased with the control or test foods compared with the washout food. In addition, bacterial genera that are decreased in the feces of those with anxiety-like disorders were increased following the consumption of the control or test foods. Overall, these data indicate that foods supplemented with omega-3 fatty acids and selected fiber and polyphenol sources lead to beneficial changes in anxiety-related metabolites and gut bacteria.

Abstract

A nutrition-based approach was utilized to examine the effects of fish oil and a polyphenol blend (with or without tomato pomace) on the fecal microbiota and plasma/fecal metabolomes. Forty dogs, aged 5–14 years, were fed a washout food, then randomized to consume a control (fish oil and polyphenol blend without tomato pomace) or test (fish oil and polyphenol blend with tomato pomace) food, then the washout food, and crossed over to consume the test or control food; each for 30 days. Several metabolites differed when comparing consumption of the washout with either the control or test foods, but few changed significantly between the test and control foods. Plasma levels of 4-ethylphenyl sulfate (4-EPS), a metabolite associated with anxiety disorders, demonstrated the largest decrease between the washout food and the control/test foods. Plasma 4-EPS levels were also significantly lower after dogs ate the test food compared with the control food. Other plasma metabolites linked with anxiety disorders were decreased following consumption of the control/test foods. Significant increases in Blautia, Parabacteroides, and Odoribacter in the fecal microbiota correlated with decreases in 4-EPS when dogs ate the control/test foods. These data indicate that foods supplemented with polyphenols and omega-3 fatty acids can modulate the gut microbiota to improve the profile of anxiety-linked metabolites.

Correlations of plasma oxytocin with clinical and hormonal parameters in panic disorder

AIMS

The potential association between oxytocin (OXT) plasma levels and clinical and hormonal parameters in panic disorder (PD) especially in its acute phase - has not been investigated as yet. This was the aim of this article.

METHOD

Twenty-four consecutively-referred, acutely-ill, medication-free PD patients with (PDA, N = 21) or without agoraphobia, moreover without comorbidities, completed the following clinical measures: Hamilton Anxiety Rating Scale (HARS); Agoraphobic Cognitions Questionnaire (ACQ); Mobility Inventory-Alone subscale (MI-alone); and number of panic attacks during last 21 d (PA21d). Plasma levels of OXT, adrenocorticotropic hormone (ACTH) and cortisol were evaluated.

RESULTS

OXT levels were significantly, negatively associated with the HARS scores (r= -0.59 p=.002) and weakly, negatively correlated with the ACQ scores (r = -0.403 p=.051). No significant correlations were traced between OXT levels and PA21d, MI-alone, ACTH, and cortisol.

CONCLUSION

In acutely-ill, medication-free PD patients, OXT plasma levels may be relevant to the severity of their 'general' anxiety symptoms, but not to the 'specific' panic psychopathology.

The relationship between the serotonergic system and COVID-19 disease: A review

COVID-19 is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which led to a pandemic started in Wuhan, China, in 2019. The rapid spread of the disease in the world, unprecedented mortality rate, and lack of definitive treatment for the disease have led to a global effort to develop effective vaccines as well as new therapeutic interventions. Immune cells activation with excessive inflammation is an important pathophysiological feature of COVID-19 that may impair the various organs functions. Accordingly, these could cause dysfunction in the brain with some symptoms such as respiratory failure, headache, impaired consciousness, olfactory and taste disorders, and severe neurological disorders such as encephalitis. It was found that there is a two-way communication between the immune system and the nervous system through classical neurotransmitters, hormones, and cytokines. Among neurotransmitters, serotonin plays important roles in the immune system and in regulating inflammatory responses by central and peripheral mechanisms. This article aimed to review the two-way relationship between the immune and the nervous systems by focusing on the serotonergic system and the emerging COVID-19 disease.

Socioemotional deficit and HPA axis time response in high compulsive rats selected by schedule-induced polydipsia

Compulsivity is a failure to stop an ongoing behavior that has become inappropriate to the situation and is recognized as a transdiagnostic trait present in different neuropsychiatric disorders. The implication of motivation and emotion, as well as the stress response in compulsive population has not been fully understood. We assessed the motivation to reward and cues, the emotional response in different contexts and the hypothalamic-pituitary-adrenal (HPA) axis response in rats selected by a preclinical model of compulsive behavior. Firstly, high (HD) or low (LD) drinkers were selected according to their drinking behavior on schedule-induced polydipsia (SIP). Then, we assessed motivation by the propensity to attribute incentive salience to rewards on Pavlovian Conditioned Approach (PavCA) and motivation to gain reward on Progressive Ratio Schedule of Reinforcement (PRSR). Emotion was measured by Social Dominance on the Tube Test (SDTT) and emotional memory on Passive Avoidance (PA). Plasma corticosterone (CORT) levels in response to SIP were assessed. HD rats showed a socioemotional deficit by fewer victories on the SDTT, and an increased latency to enter the dark compartment on the PA. No differences were found between groups regarding to motivational assessment. Moreover, HD rats revealed a blunted time response in the increase of CORT levels at 45 min after SIP compared to LD rats. The findings show that the compulsive phenotype of HD rats exhibit less social dominance, more resistance to extinction and a differential CORT time response to SIP. These findings may contribute to highlight the relevance of assessing socioemotional behaviors and stress response for a better characterization of the vulnerability to compulsive spectrum disorders.

The metacontrol hypothesis as diagnostic framework of OCD and ADHD: A dimensional approach based on shared neurobiological vulnerability

Obsessive-compulsive disorder (OCD) and attention-deficit hyperactivity disorder (ADHD) are multi-faceted neuropsychiatric conditions that in many aspects appear to be each other's antipodes. We suggest a dimensional approach, according to which these partially opposing disorders fall onto a continuum that reflects variability regarding alterations of cortico-striato-thalamo-cortical (CSTC) circuits and of the processing of neural noise during cognition. By using theoretical accounts of human cognitive metacontrol, we develop a framework according to which OCD can be characterized by a chronic bias towards exaggerated cognitive persistence, equivalent to a high signal-to-noise ratio (SNR)-which facilitates perseverative behaviour but impairs mental flexibility. In contrast, ADHD is characterized by a chronic bias towards inflated cognitive flexibility, equivalent to a low SNR-which increases behavioural variability but impairs the focusing on one goal and on relevant information. We argue that, when pharmacology is not feasible, novel treatments of these disorders may involve methods to manipulate the signal-to-noise ratio via non-invasive brain stimulation techniques, in order to normalize the situational imbalance between cognitive persistence and cognitive flexibility.

Serotonin Modulates the Correlations between Obsessive-compulsive Trait and Heart Rate Variability in Normal Healthy Subjects: A SPECT Study with [123I]ADAM and Heart Rate Variability Measurement

Objective

The impact of serotonergic system on obsessive-compulsive disorder (OCD) is well studied. However, the correlation between OC presentations and autonomic nervous system (ANS) is still unclear. Furthermore, whether the correlation might be modulated by serotonin is also uncertain.

Methods

We recruited eighty-nine healthy subjects. Serotonin transporter (SERT) availability by [¹²³I]ADAM and heart rate variability (HRV) tests were measured. Symptoms checklist-90 was measured for the OC presentations. The interaction between HRV and SERT availability were calculated and the correlation between HRV and OC symptoms were analyzed after stratified SERT level into two groups, split at medium.

Results

The interactions were significant in the factors of low frequency (LF), high frequency (HF), and root mean square of successive differences (RMSSD). Furthermore, the significantly negative correlations between OC symptoms and the above HRV indexes existed only in subjects with higher SERT availability.

Conclusion

OC symptoms might be correlated with ANS regulations in subjects with higher SERT availability.