The effects of ketamine and classic hallucinogens on neurotrophic and inflammatory markers in unipolar treatment-resistant depression: a systematic review of clinical trials.

Although results are still preliminary, ketamine and classical hallucinogens have shown promise in recent years as novel, fast-acting antidepressants, especially for the treatment of unipolar treatment-resistant depression (TRD). Depression also seems to be related to abnormal levels of peripheral inflammatory and neurotrophic biomarkers, which may one day help to diagnose of this disorder. In this context, this systematic review of clinical trials evaluated the current evidence that relates the antidepressant effects of ketamine and classical hallucinogens on TRD with changes in inflammatory and neurotrophic biomarkers. Twelve studies were found (n = 587), 2 with oral ayahuasca (1 mL/kg) and 10 with ketamine (mostly intravenous 0.5 mg/kg) administration. Results for all biomarkers assessed were contradictory and thus inconclusive. Randomized controlled trials with bigger samples and higher statistical power are warranted to clarify if peripheral biomarkers can confidently be used to indicate and measure ketamine's and classical hallucinogens' antidepressant effect. The PROSPERO ID for this study is CRD42021249089.

Paraneoplastic and autoimmune encephalitis: Alterations of mood and emotion.

Autoimmune encephalitis often produces signs and symptoms that appear to be at the interface between neurology and psychiatry. Since psychiatric symptoms are often prominent, patients are often first seen in a psychiatric setting. Therefore it is important that psychiatrists, as well as neurologists, be able to recognize autoimmune encephalitis, a task that is often difficult. Early diagnosis of autoimmune encephalitis is crucial as this will usually result in a better outcome for the patient. This chapter provides an introduction to various autoimmune encephalitides and describes their pathophysiology and the possible associated neuropsychiatric, neuropsychological (cognitive), and neurological (sensory-motor) signs and symptoms. This chapter also reviews the possible treatments of these associated signs and symptoms.

A review of effects of calorie restriction and fasting with potential relevance to depression.

In recent years, there has been a great deal of interest in the effects of calorie reduction (calorie restriction) and fasting on depression. In the current paper, we have reviewed the literature in this area, with discussion of the possible neurobiological mechanisms involved in calorie restriction and intermittent fasting. Factors which may play a role in the effects of these dietary manipulations on health include changes involving free fatty acids, ketone bodies, neurotransmitters, cyclic adenosine monophosphate response element binding protein (CREB), brain-derived neurotrophic factor (BDNF), cytokines, orexin, ghrelin, leptin, reactive oxygen species and autophagy. Several of these factors are potential contributors to improving symptoms of depression. Challenges encountered in research on calorie restriction and intermittent fasting are also discussed. Although much is now known about the acute effects of calorie restriction and intermittent fasting, further long term clinical studies are warranted.

Neuroimmunological antibody-mediated encephalitis and implications for diagnosis and therapy in neuropsychiatry.

The past decade has seen a surge of reports and investigations into cases of autoimmune-mediated encephalitis. The increasing recognition of these disorders is especially of relevance to the fields of neurology and psychiatry. Autoimmune encephalitis involves antibodies against synaptic receptors, neuronal cell surface proteins and intracellular targets. These disorders feature prominent symptoms of cognitive impairment and behavioural changes, often associated with the presence of seizures. Early in the clinical course, autoimmune encephalitis may manifest as psychiatric symptoms of psychosis and involve psychiatry as an initial point of contact. Although commonly associated with malignancy, these disorders can present in the absence of an inciting neoplasm. The identification of autoimmune encephalitis is of clinical importance as a large proportion of individuals experience a response to immunotherapy. This review focuses on the current state of knowledge on n-methyl-d-aspartate (NMDA) receptor-associated encephalitis and limbic encephalitis, the latter predominantly involving antibodies against the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor, the γ-aminobutyric acid (GABA)B receptor and leucine-rich glioma-inactivated 1 (LGI1) protein. In addition, we briefly describe anti-dopamine D2 receptor encephalitis. A summary of the literature will focus on common clinical presentations and course, diagnostic approaches and response to treatment. Since a substantial proportion of patients with autoimmune encephalitis exhibit symptoms of psychosis, the relevance of this disorder to theories of psychosis and schizophrenia will also be discussed.

Effects of sodium nitroprusside in the prevention of schizophrenia-like symptoms induced by ketamine - A translational double-blind study

Abstract Background: Recent evidence has shown improvements in schizophrenia symptoms after the infusion of sodium nitroprusside (SNP), a nitric oxide (NO) donor. In the rat model of schizophrenia using ketamine injection, pretreatment with SNP seems to prevent behavioral changes associated with positive symptoms for up to one week. Objective: We investigated whether SNP would have preventative effects on psychogenic symptoms induced by ketamine in healthy subjects. Methods: Healthy subjects (N = 38) were assigned to distinct groups that received SNP in different doses (0.15, 0.25, and 0.5 mcg/kg/min). First, participants received an infusion of SNP or placebo over 75 minutes. After 10 minutes, they were injected for 1 minute with a bolus of 0.26 mg/kg of ketamine and a maintenance dose was started 5 minutes later, with 0.25 mg/kg/h of ketamine for 50 minutes. Results: Ketamine-induced psychopathological alterations induced were reduced by SNP, as assessed with the Brief Psychological Rating Scale. Scores in the objective subscale of the Clinician-Administered Dissociative States Scale were also lower in SNP sessions compared to placebo. SNP had protective effects against deterioration in facial emotion and identity recognition tasks induced by ketamine. Discussion: Our findings support the view that SNP has preventative properties against psychotic manifestations.

Deep grey matter iron accumulation in alcohol use disorder.

PURPOSE: Evaluate brain iron accumulation in alcohol use disorder (AUD) patients compared to controls using quantitative susceptibility mapping (QSM). METHODS: QSM was performed retrospectively by using phase images from resting state functional magnetic resonance imaging (fMRI). 20 male AUD patients and 15 matched healthy controls were examined. Susceptibility values were manually traced in deep grey matter regions including caudate nucleus, combined putamen and globus pallidus, combined substantia nigra and red nucleus, dentate nucleus, and a reference white matter region in the internal capsule. Average susceptibility values from each region were compared between the patients and controls. The relationship between age and susceptibility was also explored. RESULTS: The AUD group exhibited increased susceptibility in caudate nucleus (+8.5%, p=0.034), combined putamen and globus pallidus (+10.8%, p=0.006), and dentate nucleus (+14.9%, p=0.022). Susceptibility increased with age in two of the four measured regions - combined putamen and globus pallidus (p=0.013) and combined substantia nigra and red nucleus (p=0.041). AUD did not significantly modulate the rate of susceptibility increase with age in our data. CONCLUSION: Retrospective QSM computed from standard fMRI datasets provides new opportunities for brain iron studies in psychiatry. Substantially elevated brain iron was found in AUD subjects in the basal ganglia and dentate nucleus. This was the first human AUD brain iron study and the first retrospective clinical fMRI QSM study.

Effects of minocycline add-on treatment on brain morphometry and cerebral perfusion in recent-onset schizophrenia.

Increasing evidence suggests that the tetracycline antibiotic minocycline has neuroprotective effects and is a potential treatment for schizophrenia. However, the mechanisms of action of minocycline in the CNS remain elusive. The aim of this study was to investigate the effects of minocycline on brain morphology and cerebral perfusion in patients with recent-onset schizophrenia after 12months of a randomized double-blind, placebo-controlled clinical trial of minocycline add-on treatment. This study included 24 outpatients with recent-onset schizophrenia randomized for 12months of adjuvant treatment with minocycline (200mg/d) or placebo. MRI (1.5T) and [(99m)Tc]-ECD SPECT brain scans were performed at the end of the 12-month of trial. Between-condition comparisons of SPECT and MRI brain images were performed using statistical parametric mapping and analyzed by voxel-based morphometry (VBM). Minocycline adjuvant treatment significantly reduced positive and negative symptoms when compared with placebo. The VBM analysis of MRI scans showed that the patients in the placebo group had significant lower gray matter volumes in the midposterior cingulate cortex and in the precentral gyrus in comparison with the patients in the minocycline group. In addition, a decreased ECD uptake in the minocycline condition was observed in fronto-temporal areas. These results suggest that minocycline may protect against gray matter loss and modulate fronto-temporal areas involved in the pathophysiology of schizophrenia. Furthermore, minocycline add-on treatment may be a potential treatment in the early stages of schizophrenia and may ameliorate clinical deterioration and brain alterations observed in this period.

Nitric oxide plasma/serum levels in patients with schizophrenia: a systematic review and meta-analysis / Níveis plasmáticos/séricos do óxido nítrico em pacientes com esquizofrenia: uma revisão sistemática e metanálise

For the last 40 years, schizophrenia has been considered to be the result primarily of a dysfunction in brain dopaminergic pathways. In this review, it is described and discussed findings concerning nitric oxide-mediated neurotransmission in schizophrenia. Studies were searched in PubMed, SciELO, and LILACS using the terms schizophrenia and nitric oxide plasma levels or nitric oxide serum levels, with no time limit. The reference lists of selected articles were also hand-searched for additional articles. From 15 potential reports, 10 were eligible to be included in the review and meta-analysis. These studies included a total of 505 patients with schizophrenia and 339 healthy volunteers. No significant difference was found between patients and healthy controls regarding total nitrite plasma/serum levels (effect size g = 0.285, 95%CI = -0.205 to 0.774, p = 0.254). However, when studies with patients under antipsychotic treatment were examined separately, there was a significant difference between patients and healthy volunteers (effect size g = 0.663, 95%CI = 0.365 to 0.961, p < 0.001), showing that patients under treatment have higher levels of plasma/serum nitric oxide than controls. These results suggest that antipsychotics increase nitric oxide plasma/serum levels and that the nitrergic pathway would be a fertile target for the development of new treatments for patients with schizophrenia.

Durante os últimos 40 anos, a esquizofrenia foi considerada, principalmente, como o resultado de disfunções dopaminérgicas no cérebro. Esta revisão descreve e discute algumas descobertas sobre a neurotransmissão mediada pelo óxido nítrico na esquizofrenia. A busca foi feita nas bases PubMed, SciELO e LILACS usando-se os termos schizophrenia e nitric oxide plasma levels ou nitric oxide serum levels, sem limites de tempo. As listas de referências dos artigos selecionados foram examinadas em busca de outras publicações pertinentes. Dentre 15 artigos passíveis de serem incluídos, 10 preenchiam os critérios estabelecidos para a revisão e metanálise. Esses estudos incluíram 505 pacientes com esquizofrenia e 339 voluntários saudáveis. Não foram encontradas diferenças significativas entre pacientes e voluntários saudáveis quanto aos níveis plasmáticos de nitrito total (effect size g = 0,285, IC 95% = -0,205 a 0,774, p = 0,254). No entanto, o exame separado dos estudos envolvendo pacientes em tratamento antipsicótico apresentou diferenças significativas entre pacientes e voluntários saudáveis (effect size g = 0,663, IC 95% = 0,365 to 0,961, p < 0,001), demonstrando que pacientes em tratamento possuem níveis plasmáticos mais altos de óxido nítrico. Esses resultados sugerem que os antipsicóticos podem aumentar os níveis plasmáticos de óxido nítrico e que a via nitrérgica (e sua estimulação) constituiria um alvo propício para o desenvolvimento de novos tratamentos para pacientes com esquizofrenia.

The antidepressant phenelzine protects neurons and astrocytes against formaldehyde-induced toxicity.

Reactive aldehydes have been implicated in the etiology of several neurological and psychiatric disorders, and there is considerable interest in drugs to counteract the actions of these aldehydes. Increased formaldehyde (FA) and up-regulation of semicarbazide-sensitive amine oxidase, which forms FA from methylamine, have been implicated in disorders such as cerebrovascular disorders, alcohol abuse, diabetes and Alzheimer's disease. Phenelzine (PLZ), a monoamine oxidase inhibitor, is an antidepressant that has recently received attention for its neuroprotective/neurorescue properties. We investigated FA-induced toxicity and the effects of PLZ using rat primary cortical neurons and astrocytes and found that FA induced toxicity in neurons and astrocytes by multiple means. In astrocytes, FA decreased glutamate transporter expression, inhibiting glutamate uptake. PLZ reversed the decrease of glutamate uptake and the alteration of the second messengers, AKT and p38, induced by FA. PLZ alone affected the GLT-1 glutamate transporter in opposite directions in astrocytes and neurons. Thus, PLZ has multiple actions in neurons and astrocytes that may contribute to its neuroprotection.

Neurological complications of psychiatric drugs: clinical features and management.

This paper reviews the main neurological complications of psychiatric drugs, in particular antipsychotics and antidepressants. Extrapyramidal syndromes include acute dystonia, parkinsonism, akathisia, tardive dyskinesia and tardive dystonia. Extrapyramidal symptoms (EPS) are less frequent with atypical than with conventional antipsychotics but remain common in clinical practice partly due to lack of screening by health professionals. Neuroleptic malignant syndrome (NMS) consists of severe muscle rigidity, pyrexia, change in conscious level and autonomic disturbance but partial forms also occur. NMS is particularly associated with the initiation and rapid increase in dose of high-potency antipsychotics but it has been reported with all the atypical antipsychotics and rarely with other drugs including antidepressants. Serotonin toxicity comprises altered mental state (agitation, excitement, confusion), neuromuscular hyperactivity (tremor, clonus, myoclonus, hyper-reflexia) and autonomic hyperactivity and occurs on a spectrum. Severe cases, termed serotonin syndrome, usually follow the co-prescription of drugs that increase serotonergic transmission by different pathways, for example a monoamine oxidase inhibitor (MAOI) and a selective serotonin reuptake inhibitor (SSRI). Most antipsychotics and antidepressants lower the seizure threshold and can cause seizures; the risk is greater with clozapine than with other atypical antipsychotics and greater with tricyclic antidepressants (TCAs) than with SSRIs. In randomised controlled trials in elderly patients with dementia atypical antipsychotics are associated with a higher risk of stroke and death than placebo. Cohort studies suggest that conventional drugs carry at least the same risk. Cessation of treatment with antipsychotics and antidepressants can lead to a wide range of discontinuation symptoms which include movement disorders and other neurological symptoms. Clinicians need to be familiar with strategies to reduce the risk of these adverse events and to manage them when they arise. Their occurrence needs to be balanced against the benefits of psychiatric drugs in terms of efficacy and improved quality of life in a range of disorders.