Long COVID in Children, Adults, and Vulnerable Populations: A Comprehensive Overview for an Integrated Approach.

Long COVID affects both children and adults, including subjects who experienced severe, mild, or even asymptomatic SARS-CoV-2 infection. We have provided a comprehensive overview of the incidence, clinical characteristics, risk factors, and outcomes of persistent COVID-19 symptoms in both children and adults, encompassing vulnerable populations, such as pregnant women and oncological patients. Our objective is to emphasize the critical significance of adopting an integrated approach for the early detection and appropriate management of long COVID. The incidence and severity of long COVID symptoms can have a significant impact on the quality of life of patients and the course of disease in the case of pre-existing pathologies. Particularly, in fragile and vulnerable patients, the presence of PASC is related to significantly worse survival, independent from pre-existing vulnerabilities and treatment. It is important try to achieve an early recognition and management. Various mechanisms are implicated, resulting in a wide range of clinical presentations. Understanding the specific mechanisms and risk factors involved in long COVID is crucial for tailoring effective interventions and support strategies. Management approaches involve comprehensive biopsychosocial assessments and treatment of symptoms and comorbidities, such as autonomic dysfunction, as well as multidisciplinary rehabilitation. The overall course of long COVID is one of gradual improvement, with recovery observed in the majority, though not all, of patients. As the research on long-COVID continues to evolve, ongoing studies are likely to shed more light on the intricate relationship between chronic diseases, such as oncological status, cardiovascular diseases, psychiatric disorders, and the persistent effects of SARS-CoV-2 infection. This information could guide healthcare providers, researchers, and policymakers in developing targeted interventions.

Emotion dysregulation links pathological eating styles and psychopathological traits in bariatric surgery candidates.

Objectives: Approximately one-third of bariatric surgery patients experience weight regain or suboptimal weight loss within five years post-surgery. Pathological eating styles and psychopathological traits (e.g., emotion dysregulation) are recognized as potential hindrances to sustain weight loss efforts and are implicated in obesity development. A comprehensive understanding of these variables and their interplays is still lacking, despite their potential significance in developing more effective clinical interventions for bariatric patients. We investigate the prevalence of and interactions between pathological eating styles and psychopathological traits in this population. Materials and methods: 110 bariatric surgery candidates were characterized using the Binge Eating Scale (BES), Hamilton Depression/Anxiety Scales (HAM-D/A), Barratt Impulsiveness Scale (BIS-11), Experiences in Close Relationships (ECR), Difficulties in Emotion Regulation Scale (DERS). We analyzed these variables with multiple logistic regression analyses and network analysis. Results: Patients with pathological eating styles showed more pronounced anxiety/depressive symptoms and emotion dysregulation. Network analysis revealed strong connections between BES and DERS, with DERS also displaying robust connections with HAM-A/D and ECR scales. DERS and attention impulsivity (BIS-11-A) emerged as the strongest nodes in the network. Discussion: Our findings demonstrate the mediating role of emotion dysregulation between pathological eating styles and psychopathological traits, supporting existing literature on the association between psychopathological traits, insecure attachment styles, and pathological eating behaviors. This research emphasizes the significance of emotion regulation in the complex network of variables contributing to obesity, and its potential impact on bariatric surgery outcomes. Interventions focusing on emotion regulation may thus lead to improved clinical outcomes for bariatric patients.

Lessons from a multicenter, international, large sample size analysis of patients with obsessive-compulsive disorders: an overview of the ICOCS Snapshot studies.

Obsessive-compulsive disorder (OCD) is a prevalent and highly disabling condition, characterized by a range of phenotypic expressions, potentially associated with geo-cultural differences. This article aims to provide an overview of the published studies by the International College of Obsessive-Compulsive Spectrum Disorders, in relation to the Snapshot database which has, over the past 10 years, gathered clinical naturalistic data from over 500 patients with OCD attending various research centers/clinics worldwide. This collaborative effort has provided a multi-cultural worldwide perspective of different socio-demographic and clinical features of patients with OCD. Data on age, gender, smoking habits, age at onset, duration of illness, comorbidity, suicidal behaviors, and pharmacological treatment strategies are presented here, showing peculiar differences across countries.

Partial Response to Antidepressant Treatment: The Role of Nutraceutical Compounds.

Objective: Depression represents one of the most severe psychiatric disorders, characterized by low mood episodes, as well as loss of interest. Major Depressive Episodes (MDE) treatment relies primarily on monoaminergic prescriptions. However, although the presence of many antidepressant medications, their efficacy is still partial. A promising intervention to improve antidepressant treatment may be the use of adjunctive nutraceuticals. Aim of the present study was to assess the efficacy of a N-Acetyl-cysteine, S-Adenosyl-L-Methionine and Folic acid's combination for the treatment of depressive symptoms in a sample of MDE patients. Method: Fifty outpatients with a MDE diagnosis in the context of different psychiatric disorders such as Major Depression, Bipolar Disorder, Anxiety disorders, and Personality disorders were recruited. The sample was divided into different groups based on the nutraceutical administration: a) concurrently with an AD (starter group); b) add-on to an already prescribed treatment; c) single treatment. Results: A significant reduction of CGI-Severity and Improvement scores from baseline to the end of treatment was found. Moreover, the starter group showed a significantly greater CGI-Improvement score compared to the other groups. Ninety-four percent of patients did not show any side effects. Conclusions: The present study showed promising results for the use of nutraceuticals in the add-on treatment of MDE. Those compounds may be considered a versatile, tolerable, and effective add-on treatment for the reduction of depressive symptoms impact and for improving the functioning of patients affected by MDE.

Cannabis use and related clinical variables in patients with obsessive-compulsive disorder.

OBJECTIVE: Limited studies have investigated cannabis use in patients with obsessive-compulsive disorder (OCD), despite its widespread use by patients with psychiatric illnesses. The aim of this study was to assess the frequency, correlates, and clinical impact of cannabis use in an Italian sample of patients with OCD. METHODS: Seventy consecutive outpatients with OCD were recruited from a tertiary specialized clinic. To assess cannabis-related variables, patients completed a questionnaire developed for the purpose of this study, investigating cannabis use-related habits and the influence of cannabis use on OCD symptoms and treatments. A set of clinician and self-reported questionnaires was administered to measure disease severity. The sample was then divided into three subgroups according to the pattern of cannabis use: "current users" (CUs), "past-users" (PUs), and "non-users" (NUs). RESULTS: Approximately 42.8% of patients reported lifetime cannabis use and 14.3% reported current use. Approximately 10% of cannabis users reported an improvement in OCD symptoms secondary to cannabis use, while 23.3% reported an exacerbation of anxiety symptoms. CUs showed specific unfavorable clinical variables compared to PUs and NUs: a significant higher rate of lifetime use of tobacco, alcohol, and other substances, and a higher rate of pre-OCD onset comorbidities. Conversely, the three subgroups showed a similar severity of illness. CONCLUSION: A considerable subgroup of patients with OCD showed a predisposition towards cannabis use and was associated with some specific clinical characteristics, suggesting the need for targeted consideration and interventions in this population.

Personality traits and efficacy of anti-CGRP monoclonal antibodies in migraine prevention.

BACKGROUND: Anti-CGRP monoclonal antibodies (CGRPmAbs) enlarged migraine prevention options. They work targetedly, safely, and efficiently in many patients. Inexplicably, a proportion of patients show scarce improvement. OBJECTIVE: To identify the possible role of personality traits, determined with the Personality Inventory for DSM5 (PID5), on the efficacy of CGRPmAbs on migraine. METHODS: We evaluated 3 parameters: monthly headache days (MHD), monthly painkillers intake (MPI), and MIDAS. For each parameter, patients were classified as: (A) non-responders (reduction < 3 0% vs. baseline); (B) partial responders (30-49% reduction); (C) full responders (reduction > 50%). RESULTS: Ninety-seven patients treated with CGRP-mAbs were included (33 galcanezumab, 13 fremanezumab, 51 erenumab). Considering attack reduction (MHD), 53 (54.6%) were full responders, 13 (13.4%) partial responders, and 31 (32%) non-responders. Considering MPI, 61 (62.9%) were full responders, 11 (11.3%) partial responders, and 24 (24.7%) non-responders. Concerning MIDAS, 53 (53%) were full responders, 17 (17.5%) partial responders, and 21 (21.6%) were non-responders. All the 97 patients were tested with the PID5. In terms of MHDs, non-responders, in comparison with responders, showed a significant excess of disinhibition, especially in relation with the anhedonia and depressivity facets. Concerning MPI, non-responders showed increased depressivity and distractibility. MIDAS non-responders had significantly higher scores in the antagonism domain and submissiveness facet. DISCUSSION: Non-responders seem to have different personality traits in comparison to responders, with a higher tendency toward depressed mood and difficulty to feel pleasure previously found in migraineurs vs. non-migraineurs: the more strict certain traits are, the more difficult to treat the migraine could be.

Clinical uses of Bupropion in patients with Parkinson's disease and comorbid depressive or neuropsychiatric symptoms: a scoping review.

OBJECTIVE: Bupropion, an antidepressant inhibiting the reuptake of dopamine and noradrenaline, should be useful to treat depressive symptoms in patients with Parkinson's disease (PD). Limited and conflicting literature data questioned its effectiveness and safety in depressed PD patients and extended its use to other neuropsychiatric symptoms associated with this disorder. DESIGN: The databases PubMed, Embase, Web of Sciences, Cochrane Library, and the grey literature were searched. Following a scoping review methodology, articles focusing on Bupropion uses in PD patients who manifested depressive or other neuropsychiatric alterations were reviewed. RESULTS: Twenty-three articles were selected, including 7 original articles, 3 systematic reviews or meta-analyses, 11 case reports, 1 clinical guideline, and 1 expert opinion. Bupropion showed considerable effectiveness in reducing depressive symptoms, particularly in relation to apathy. Solitary findings showed a restorative effect on compulsive behaviour secondary to treatment with dopamine as well as on anxiety symptoms. The effect on motor symptoms remains controversial. The safety profile of this medication seems positive, but additional precautions should be used in subjects with psychotic symptoms. CONCLUSION: The available literature lacks good evidence to support the use of Bupropion in PD patients presenting depressive symptoms. Further investigations are needed to extend and confirm reported findings and to produce accurate clinical guidelines.

'In the night kitchen': A scoping review on the night eating syndrome.

BACKGROUND: First described in 1955, night eating syndrome refers to an abnormal eating behavior clinically defined by the presence of evening hyperphagia (>25% of daily caloric intake) and/or nocturnal awaking with food ingestion occurring ⩾ 2 times per week. AIMS: Although the syndrome is frequently comorbid with obesity, metabolic and psychiatric disorders, its etiopathogenesis, diagnosis, assessment and treatment still remain not fully understood. METHODS: This review was conducted according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines; PubMed database was searched until 31 October 2020, using the key terms: 'Night Eating Syndrome' AND 'complications' OR 'diagnosis' OR 'drug therapy' OR 'epidemiology' OR 'etiology' OR 'physiology' OR 'physiopathology' OR 'psychology' OR 'therapy'. RESULTS: From a total of 239 citations, 120 studies assessing night eating syndrome met the inclusion criteria to be included in the review. CONCLUSION: The inclusion of night eating syndrome into the Diagnostic and Statistical Manual of Mental Disorders-5 'Other Specified Feeding or Eating Disorders' category should drive the attention of clinician and researchers toward this syndrome that is still defined by evolving diagnostic criteria. The correct identification and assessment of NES could facilitate the detection and the diagnosis of this disorder, whose bio-psycho-social roots support its multifactorial nature. The significant rates of comorbid illnesses associated with NES and the overlapping symptoms with other eating disorders require a focused clinical attention. Treatment options for night eating syndrome include both pharmacological (selective serotonin reuptake inhibitors, topiramate and melatonergic drugs) and non-pharmachological approaches; the combination of such strategies within a multidisciplinary approach should be addressed in future, well-sized and long-term studies.

Polypharmacy as maintenance treatment in bipolar illness: A systematic review.

OBJECTIVES: Polypharmacy is common in maintenance treatment of bipolar illness, but proof of greater efficacy compared to monotherapy is assumed rather than well known. We systematically reviewed the evidence from the literature to provide recommendations for clinical management and future research. METHOD: A systematic review was conducted on the use of polypharmacy in bipolar prophylaxis. Relevant papers published in English through 31 December 2019 were identified searching the electronic databases MEDLINE, Embase, PsycINFO, and the Cochrane Library. RESULTS: Twelve studies matched inclusion criteria, including 10 randomized controlled trials (RCTs). The best drug combination in prevention is represented by lithium + valproic acid which showed a significant effect on time to mood relapses (HR = 0.57) compared to valproic acid monotherapy, especially for manic episodes (HR = 0.51). The effect was significant in terms of time to new drug treatment (HR = 0.51) and time to hospitalization (HR = 0.57). A significant reduction in the frequency of mood relapses was also reported for lithium + valproic acid vs. lithium monotherapy (RR=0.12); however, the trial had a small sample size. Lamotrigine + valproic acid reported significant efficacy in prevention of depressive episodes compared to lamotrigine alone. CONCLUSIONS: The literature to support a generally greater efficacy with polypharmacy in bipolar illness is scant and heterogeneous. Within that limited evidence base, the best drug combination in bipolar prevention is represented by lithium + valproic acid for manic, but not depressive episodes. Clinical practice should focus more on adequate monotherapy before considering polypharmacy.

Reopening Endoscopy after the COVID-19 Outbreak: Indications from a High Incidence Scenario.

.

Healthy Eating, Physical Activity, and Sleep Hygiene (HEPAS) as the Winning Triad for Sustaining Physical and Mental Health in Patients at Risk for or with Neuropsychiatric Disorders: Considerations for Clinical Practice.

Neuropsychiatric disorders stem from gene-environment interaction and their development can be, at least in some cases, prevented by the adoption of healthy and protective lifestyles. Once full blown, neuropsychiatric disorders are prevalent conditions that patients live with a great burden of disability. Indeed, the determinants that increase the affliction of neuropsychiatric disorders are various, with unhealthy lifestyles providing a significant contribution in the interplay between genetic, epigenetic, and environmental factors that ultimately represent the pathophysiological basis of these impairing conditions. On one hand, the adoption of Healthy Eating education, Physical Activity programs, and Sleep hygiene promotion (HEPAS) has the potential to become one of the most suitable interventions to reduce the risk to develop neuropsychiatric disorders, while, on the other hand, its integration with pharmacological and psychological therapies seems to be essential in the overall management of neuropsychiatric disorders in order to reduce the disability and improve the quality of life of affected patients. We present an overview of the current evidence in relation to HEPAS components in the prevention and management of neuropsychiatric disorders and provide suggestions for clinical practice.

Changes in eating behavior after deep brain stimulation for anorexia nervosa. A case study.

PURPOSE: The purpose of this study was to evaluate changes in the nutritional status, body image concerns, and eating behaviors occurring in a patient who underwent deep brain stimulation (DBS) of the bed nucleus of the stria terminalis for treatment-refractory anorexia nervosa (AN). METHODS: Bilateral DBS of the bed nucleus of the stria terminalis was performed in a 37-year-old woman affected by refractory AN. Pre- and post-surgical evaluations were conducted via an array of validated testing instruments, which took into account the weight variations, body image concerns, eating behavior, quality of life, and nutritional status. RESULTS: Overall, eating behavior-, body image concern-, and nutritional status-related testing instruments demonstrated improvements starting from the first post-operative month. Normal body weight was restored after 4 months of stimulation. DISCUSSION: Only a few cases of DBS for AN have been conducted to determine the efficacy of surgery based upon weight variation and psychometric scales for anxiety and affective disorders. In contrast, we have designed a comprehensive approach taking into account the most important aspects of this disease. This approach should be considered in future studies dealing with the neurosurgical treatment of AN.

Food Bioactive Compounds and Their Interference in Drug Pharmacokinetic/Pharmacodynamic Profiles.

Preclinical and clinical studies suggest that many food molecules could interact with drug transporters and metabolizing enzymes through different mechanisms, which are predictive of what would be observed clinically. Given the recent incorporation of dietary modifications or supplements in traditional medicine, an increase in potential food-drug interactions has also appeared. The objective of this article is to review data regarding the influence of food on drug efficacy. Data from Google Scholar, PubMed, and Scopus databases was reviewed for publications on pharmaceutical, pharmacokinetic, and pharmacodynamic mechanisms. The following online resources were used to integrate functional and bioinformatic results: FooDB, Phenol-Explorer, Dr. Duke's Phytochemical and Ethnobotanical Databases, DrugBank, UniProt, and IUPHAR/BPS Guide to Pharmacology. A wide range of food compounds were shown to interact with proteins involved in drug pharmacokinetic/pharmacodynamic profiles, starting from drug oral bioavailability to enteric/hepatic transport and metabolism, blood transport, and systemic transport/metabolism. Knowledge of any food components that may interfere with drug efficacy is essential, and would provide a link for obtaining a holistic view for cancer, cardiovascular, musculoskeletal, or neurological therapies. However, preclinical interaction may be irrelevant to clinical interaction, and health professionals should be aware of the limitations if they intend to optimize the therapeutic effects of drugs.

Psychiatric, behavioral, and cognitive disorders in patients with extracranial cancers.

Patients with cancer may report neuropsychiatric abnormalities including cognitive impairment, behavioral disturbances, and psychiatric disorders that potentially worsen their quality of life, reduce their treatment response, and aggravate their overall prognosis. Neuropsychiatric disturbances have a different pathophysiology, including immuno-inflammatory and neuroendocrine mechanisms, as a consequence of oncologic treatments (chemo- and radio-therapy). Among clinicians involved in the management of such patients, psychiatrists need to pay particular attention in recognizing behavioral disturbances that arise in oncologic patients, and determining those that may be effectively treated with psychotropic medications, psychotherapeutic interventions, and an integration of them. Through the contribution of different clinicians actively involved in the management of oncological patients, the present review is ultimately aimed at updating psychiatrists in relation to the pathophysiological mechanisms responsible for the onset of cognitive, affective, and behavioral syndromes in these patients, along with epidemiologic and clinical considerations and therapeutic perspectives.

Clinical characterization of Italian suicide attempters with bipolar disorder.

IntroductionBipolar disorder (BD) is a chronic, highly disabling condition associated with psychiatric/medical comorbidity and substantive morbidity, mortality, and suicide risks. In prior reports, varying parameters have been associated with suicide risk. OBJECTIVES: To evaluate sociodemographic and clinical variables characterizing Italian individuals with BD with versus without prior suicide attempt (PSA). METHODS: A sample of 362 Italian patients categorized as BD according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM IV-TR) was assessed and divided in 2 subgroups: with and without PSA. Sociodemographic and clinical variables were compared between prior attempters and non-attempters using corrected multivariate analysis of variance (MANOVA). RESULTS: More than one-fourth of BD patients (26.2%) had a PSA, with approximately one-third (31%) of these having>1 PSA. Depressive polarity at onset, higher number of psychiatric hospitalizations, comorbid alcohol abuse, comorbid eating disorders, and psychiatric poly-comorbidity were significantly more frequent (p<.05) in patients with versus without PSA. Additionally, treatment with lithium, polypharmacotherapy (≥4 current drugs) and previous psychosocial rehabilitation were significantly more often present in patients with versus without PSA. CONCLUSIONS: We found several clinical variables associated with PSA in BD patients. Even though these retrospective findings did not address causality, they could be clinically relevant to better understanding suicidal behavior in BD and adopting proper strategies to prevent suicide in higher risk patients.

Italian patients with more recent onset of Major Depressive Disorder have a shorter duration of untreated illness.

BACKGROUND: Previous investigation on the duration of untreated illness (DUI) in patients with Major Depressive Disorder (MDD) revealed a different latency to first antidepressant treatment, with adverse consequences in terms of outcome for individuals with a longer DUI. Recent reports, moreover, documented a reduced DUI, as observed with the passage of time, in patients with different psychiatric disorders. Hence, the present study was aimed to assess DUI and related variables in a sample of Italian patients with MDD as well as to investigate potential differences in subjects with onset before and after 2000. METHODS: An overall sample of 188 patients with MDD was assessed through a specific questionnaire investigating DUI and other variables related to the psychopathological onset and latency to first antidepressant treatment, after dividing them in two different subgroups on the basis of their epoch of onset. RESULTS: The whole sample showed a mean DUI of approximately 4.5 years, with patients with more recent onset showing a significantly shorter latency to treatment compared with the other group (27.1±42.6 vs 75.8±105.2 months, P<.05). Other significant differences emerged between the two subgroups, in terms of rates of onset-related stressful events and benzodiazepine prescription, respectively, higher and lower in patients with more recent onset. CONCLUSIONS: Our findings indicate a significant DUI reduction in MDD patients whose onset occurred after vs before 2000, along with other relevant differences in terms of onset-related correlates and first pharmacotherapy. Further studies with larger samples are warranted to confirm the present findings in Italy and other countries.

Cigarette smoking in patients with obsessive compulsive disorder: a report from the International College of Obsessive Compulsive Spectrum Disorders (ICOCS).

Obsessive compulsive disorder (OCD) showed a lower prevalence of cigarette smoking compared to other psychiatric disorders in previous and recent reports. We assessed the prevalence and clinical correlates of the phenomenon in an international sample of 504 OCD patients recruited through the International College of Obsessive Compulsive Spectrum Disorders (ICOCS) network. Cigarette smoking showed a cross-sectional prevalence of 24.4% in the sample, with significant differences across countries. Females were more represented among smoking patients (16% vs 7%; p<.001). Patients with comorbid Tourette's syndrome (p<.05) and tic disorder (p<.05) were also more represented among smoking subjects. Former smokers reported a higher number of suicide attempts (p<.05). We found a lower cross-sectional prevalence of smoking among OCD patients compared to findings from previous studies in patients with other psychiatric disorders but higher compared to previous and more recent OCD studies. Geographic differences were found and smoking was more common in females and comorbid Tourette's syndrome/tic disorder.

Cytokine polymorphisms in the pathophysiology of mood disorders.

INTRODUCTION: An increasing amount of data suggests that dysregulation of the immune system, including the cytokine network, is associated with the etiology and pathophysiology of mood disorders. Genes encoding cytokines are highly polymorphic and single nucleotide polymorphisms, associated with increased or reduced cytokine production, have been described. The aim of this study was to define the genetic immunologic scenario associated with major depressive disorder (MDD) and bipolar disorder. METHODS: Eighty-four Italian outpatients affected by bipolar disorder type I, bipolar disorder type II, or MDD, and 363 healthy controls were enrolled into the study. We analyzed allele and genotype distribution of -308 (G/A) tumor necrosis factor-a (TNF-a), +874 (T/A) interferon-g (IFN-g), -174 (G/C) interleukin (IL)-6, and -1082 (G/A) IL-10 promoter polymorphisms by Polymerase Chain Reaction Sequence Specific Primers technique. RESULTS: We observed different genotype and allele distributions of TNF-a, IFN-g, and IL-10 polymorphisms in the three groups of patients analyzed. In particular, bipolar II patients were characterized by an absence of adenine (A) high producer allele of TNF-a (P<.001) and a lower percentage of TT high producer genotype of IFN-g (P<.001); bipolar I individuals showed reduced percentage of AA low producer genotype of IL-10 (P<.001). Both bipolar I and bipolar II patients not carrying guanine (G) high producer IL-6 allele showed a lower mean age at onset (P=.048). CONCLUSION: These data support the existence of a genetic profile related to pro-inflammatory cytokines in patients affected by mood disorders. The differences observed across the three clinical phenotypes suggest the presence of different pathogenetic mechanisms involved in the susceptibility of phenotypically different mood disorders.

Presence of D4 dopamine receptors in human prefrontal cortex: a postmortem study

OBJECTIVE: The aim of our study was to explore the presence and the distribution of D4 dopamine receptors in postmortem human prefrontal cortex, by means of the binding of [³H]YM-09151-2, an antagonist that has equal affinity for D2, D3 and D4 receptors. It was therefore necessary to devise a unique assay method in order to distinguish and detect the D4 component. METHOD: Frontal cortex samples were harvested postmortem, during autopsy sessions, from 5 subjects. In the first assay, tissue homogenates were incubated with increasing concentrations of [³H]YM-09151-2, whereas L-745870, which has a high affinity for D4 and a low affinity for D2/D3 receptors, was used as the displacer. In the second assay, raclopride, which has a high affinity for D2/D3 receptors and a low affinity for D4 receptors, was used to block D2/D3. The L-745870 (500 nM) was added to both assays in order to determine the nonspecific binding. RESULTS: Our experiments revealed the presence of specific and saturable binding of [³H]YM-09151-2. The blockade of D2 and D3 receptors with raclopride ensured that the D4 receptors were labeled. The mean maximum binding capacity was 88 ± 25 fmol/mg protein, and the dissociation constant was 0.8 ± 0.4 nM. DISCUSSION AND CONCLUSIONS: Our findings, although not conclusive, suggest that the density of D4 receptors is low in the human prefrontal cortex.

OBJETIVO: O objetivo deste estudo foi quantificar a presença e a distribuição de receptores dopaminérgicos do tipo 4 (D4) no córtex cerebral humano em amostras post-mortem através do bloqueio com ³H-YM-09151-2 - um antagonista com afinidade equivalente pelos receptores D2, D3 e D4 - e do desenvolvimento de um método para a detecção específica do componente D4. MÉTODO: Foram obtidas amostras de córtex cerebral de cinco cadáveres. Em um primeiro ensaio, os homogeneizados de tecido cerebral foram incubados em concentrações crescentes de ³H-YM-09151-2, enquanto que o L-745,870, ligante que apresenta grande afinidade pelo receptor D4 e baixa afinidade por D2 e D3, foi utilizado como controle. Em um segundo ensaio, a racloprida, que apresenta alta afinidade por receptores D2 e D3, mas baixa afinidade por D4, foi usada para bloquear D2 e D3. O L-745,870 foi adicionado em ambos os ensaios para determinar o bloqueio não específico. RESULTADOS: Os resultados do experimento demonstraram a presença de um bloqueio específico e saturável com ³H-YM-09151-2. O bloqueio de receptores D2 e D3 com racloprida confirmou que apenas os receptores D4 livres foram avaliados. A Bmax (média ± DP) foi de 88 ± 25 fmol/mg de proteínas, enquanto que a Kd (média ± DP) foi de 0,8 ± 0,4 nM. DISCUSSÃO E CONCLUSÕES: Tais achados, ainda que não definitivamente conclusivos, sugerem a presença de uma baixa densidade de receptores D4 no córtex pré-frontal humano.