Moderators of ayahuasca's biological antidepressant action.

Introduction: The understanding of biological responses to psychedelics with antidepressant potential is imperative. Here we report how a set of acute parameters, namely emotional (depressive symptoms), cognitive (psychedelic experience), and physiological (salivary cortisol), recorded during an ayahuasca dosing session, modulated serum brain-derived neurotrophic factor (BDNF), serum cortisol (SC), serum interleukin 6 (IL-6), plasma C-reactive protein (CRP), and salivary cortisol awakening response (CAR). Methods: Results were analyzed 2 days after the psychedelic intervention (ayahuasca) versus placebo in both patients with treatment-resistant depression and healthy volunteers. These measures were assessed as part of a randomized double-blinded, placebo-controlled trial (n = 72). Results: Results revealed that larger reductions of depressive symptoms during the dosing session significantly moderated higher levels of SC in patients. Whereas lesser changes in salivary cortisol levels during the ayahuasca intervention were related to higher BDNF levels in patients with a larger clinical response in the reduction in depressive symptoms. No moderator was found for patient's CAR, IL-6, and CRP responses to ayahuasca and for all biomarker responses to ayahuasca in healthy controls and in the placebo group. Discussion: In summary, some specific emotional and physiological parameters during experimental ayahuasca session were revealed as critical moderators of the improvement of major depression biomarkers, mainly BDNF and SC two days after ayahuasca intake. These findings contribute to paving the way for future studies investigating the biological antidepressant response to psychedelic therapy.

Potential biomarkers of major depression diagnosis and chronicity.

BACKGROUND: Molecular biomarkers are promising tools to be routinely used in clinical psychiatry. Among psychiatric diseases, major depression disorder (MDD) has gotten attention due to its growing prevalence and morbidity. METHODS: We tested some peripheral molecular parameters such as serum mature Brain-Derived Neurotrophic Factor (mBDNF), plasma C-Reactive Protein (CRP), serum cortisol (SC), and the salivary Cortisol Awakening Response (CAR), as well as the Pittsburgh sleep quality inventory (PSQI), as part of a multibiomarker panel for potential use in MDD diagnosis and evaluation of disease's chronicity using regression models, and ROC curve. RESULTS: For diagnosis model, two groups were analyzed: patients in the first episode of major depression (MD: n = 30) and a healthy control (CG: n = 32). None of those diagnosis models tested had greater power than Hamilton Depression Rating Scale-6. For MDD chronicity, a group of patients with treatment-resistant major depression (TRD: n = 28) was tested across the MD group. The best chronicity model (p < 0.05) that discriminated between MD and TRD included four parameters, namely PSQI, CAR, SC, and mBDNF (AUC ROC = 0.99), with 96% of sensitivity and 93% of specificity. CONCLUSION: These results indicate that changes in specific biomarkers (CAR, SC, mBDNF and PSQI) have potential on the evaluation of MDD chronicity, but not for its diagnosis. Therefore, these findings can contribute for further studies aiming the development of a stronger model to be commercially available and used in psychiatry clinical practice.

Pathophysiology of Major Depression by Clinical Stages.

The comprehension of the pathophysiology of the major depressive disorder (MDD) is essential to the strengthening of precision psychiatry. In order to determine the relationship between the pathophysiology of the MDD and its clinical progression, analyzed by severity of the depressive symptoms and sleep quality, we conducted a study assessing different peripheral molecular biomarkers, including the levels of plasma C-reactive protein (CRP), serum mature brain-derived neurotrophic factor (mBDNF), serum cortisol (SC), and salivary cortisol awakening response (CAR), of patients with MDD (n = 58) and a control group of healthy volunteers (n = 62). Patients with the first episode of MDD (n = 30) had significantly higher levels of CAR and SC than controls (n = 32) and similar levels of mBDNF of controls. Patients with treatment-resistant depression (TRD, n = 28) presented significantly lower levels of SC and CAR, and higher levels of mBDNF and CRP than controls (n = 30). An increased severity of depressive symptoms and worse sleep quality were correlated with levels low of SC and CAR, and with high levels of mBDNF. These results point out a strong relationship between the stages clinical of MDD and changes in a range of relevant biological markers. This can assist in the development of precision psychiatry and future research on the biological tests for depression.

Changes in inflammatory biomarkers are related to the antidepressant effects of Ayahuasca.

BACKGROUND: Ayahuasca is a traditional Amazon brew and its potential antidepressant properties have recently been explored in scientific settings. We conducted a double-blind placebo-controlled trial of ayahuasca with treatment-resistant depression patients (n = 28) and healthy controls (n = 45). AIMS: We are evaluating the blood inflammatory biomarkers: C-reactive protein and interleukin 6, as a potential consequence of ayahuasca intake and their correlation with serum cortisol and brain-derived neurotrophic factor levels. Blood samples were collected at pre-treatment and 48 hours after substance ingestion to assess the concentration of inflammatory biomarkers, together with administration of the Montgomery-Åsberg Depression Rating Scale. RESULTS: At pre-treatment, patients showed higher C-reactive protein levels than healthy controls and a significant negative correlation between C-reactive protein and serum cortisol levels was revealed (rho = -0.40, n = 14). C-reactive protein in those patients was not correlated with Montgomery-Åsberg Depression Rating Scale scores. We observed a significant reduction of C-reactive protein levels across time in both patients and controls treated with ayahuasca, but not with placebo. Patients treated with ayahuasca showed a significant correlation (rho = + 0.57) between larger reductions of C-reactive protein and lower depressive symptoms at 48 hours after substance ingestion (Montgomery-Åsberg Depression Rating Scale). No significant result with respect to interleukin 6 and brain-derived neurotrophic factor was found. Furthermore, these biomarkers did not predict the antidepressant response or remission rates observed. CONCLUSIONS: These findings enhance the understanding of the biological mechanisms behind the observed antidepressant effects of ayahuasca and encourage further clinical trials in adults with depression.

Changes in Cortisol but Not in Brain-Derived Neurotrophic Factor Modulate the Association Between Sleep Disturbances and Major Depression.

Sleep disturbance is a symptom consistently found in major depression and is associated with a longer course of illness, reduced response to treatment, increased risk of relapse and recurrence. Chronic insomnia has been associated with changes in cortisol and serum brain-derived neurotrophic factor (BDNF) levels, which in turn are also changed in major depression. Here, we evaluated the relationship between sleep quality, salivary cortisol awakening response (CAR), and serum BDNF levels in patients with sleep disturbance and treatment-resistant major depression (n = 18), and in a control group of healthy subjects with good (n = 21) and poor (n = 18) sleep quality. We observed that the patients had the lowest CAR and sleep duration of all three groups and a higher latency to sleep than the healthy volunteers with a good sleep profile. Besides, low CAR was correlated with more severe depressive symptoms and worse sleep quality. There was no difference in serum BDNF levels between groups with distinct sleep quality. Taken together, our results showed a relationship between changes in CAR and in sleep quality in patients with treatment-resistant depression, which were correlated with the severity of disease, suggesting that cortisol could be a physiological link between sleep disturbance and major depression.

Modulation of Serum Brain-Derived Neurotrophic Factor by a Single Dose of Ayahuasca: Observation From a Randomized Controlled Trial.

Serotonergic psychedelics are emerging as potential antidepressant therapeutic tools, as suggested in a recent randomized controlled trial with ayahuasca for treatment-resistant depression. Preclinical and clinical studies have suggested that serum brain-derived neurotrophic factor (BDNF) levels increase after treatment with serotoninergic antidepressants, but the exact role of BDNF as a biomarker for diagnostic and treatment of major depression is still poorly understood. Here we investigated serum BDNF levels in healthy controls (N = 45) and patients with treatment-resistant depression (N = 28) before (baseline) and 48 h after (D2) a single dose of ayahuasca or placebo. In our sample, baseline serum BDNF levels did not predict major depression and the clinical characteristics of the patients did not predict their BDNF levels. However, at baseline, serum cortisol was a predictor of serum BDNF levels, where lower levels of serum BDNF were detected in a subgroup of subjects with hypocortisolemia. Moreover, at baseline we found a negative correlation between BDNF and serum cortisol in volunteers with eucortisolemia. After treatment (D2) we observed higher BDNF levels in both patients and controls that ingested ayahuasca (N = 35) when compared to placebo (N = 34). Furthermore, at D2 just patients treated with ayahuasca (N = 14), and not with placebo (N = 14), presented a significant negative correlation between serum BDNF levels and depressive symptoms. This is the first double-blind randomized placebo-controlled clinical trial that explored the modulation of BDNF in response to a psychedelic in patients with depression. The results suggest a potential link between the observed antidepressant effects of ayahuasca and changes in serum BDNF, which contributes to the emerging view of using psychedelics as an antidepressant. This trial is registered at http://clinicaltrials.gov (NCT02914769).

An Overview of Animal Models Related to Schizophrenia.

Schizophrenia is a heterogeneous psychiatric disorder that is poorly treated with current therapies. In this brief review, we provide an update regarding the use of animal models to study schizophrenia in an attempt to understand its aetiology and develop novel therapeutic strategies. Tremendous progress has been made developing and validating rodent models that replicate the aetiologies, brain pathologies, and behavioural abnormalities associated with schizophrenia in humans. Here, models are grouped into 3 categories-developmental, drug induced, and genetic-to reflect the heterogeneous risk factors associated with schizophrenia. Each of these models is associated with varied but overlapping pathophysiology, endophenotypes, behavioural abnormalities, and cognitive impairments. Studying schizophrenia using multiple models will permit an understanding of the core features of the disease, thereby facilitating preclinical research aimed at the development and validation of better pharmacotherapies to alter the progression of schizophrenia or alleviate its debilitating symptoms.

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.

Nitric Oxide's Involvement in the Spectrum of Psychotic Disorders.

BACKGROUND: Recent findings suggest that dopaminergic abnormalities found in psychotic disorders may be secondary to nitric oxide dysfunctions. Nitric oxide seems to influence glutamatergic and dopaminergic neurotransmission, both of which have been associated with psychosis. OBJECTIVE: To search and review published works which examined the influence of nitric oxide in psychotic disorders subjects. METHODS: The research was executed in the on-line collections of Pubmed and ISI Web of Science. The key aspects utilized were "Psychotic Disorders AND Nitric Oxide", "Psychosis AND Nitric Oxide","Schizotypal Personality Disorder AND Nitric Oxide", "Delusional Disorder AND Nitric Oxide", "Brief Psychotic Disorder AND Nitric Oxide", "Schizophreniform Disorder AND Nitric Oxide", "Schizoaffective Disorder AND Nitric Oxide", and "Schizophrenia AND Nitric Oxide". Empirical works utilizing human subjects, published in the last 10 years, in English language were included. RESULTS: Initially, the search yielded a total of 95 studies. Then, 39 were elected according to the inclusion requirements. The selected articles were divided into five groups: biochemical studies (n=15; 38.5%), genetic studies (n=11; 28.2%), postmortem studies (n=6; 15.4%), clinical trials (n=6; 15.4%), and case reports (n=1; 2.5%). The studies evaluated only schizophrenic or schizoaffective disorder subjects. The great majority of them found evidence of nitric oxide dysfunctions in psychosis. CONCLUSIONS: The results of the review strengthen the idea that nitric oxide has a key participation in psychotic disorders and deserves deeper investigation as a target for future pharmacological intervention.

Role of Methylene Blue in Trauma Neuroprotection and Neuropsychiatric Diseases.

The prevalence of central nervous system trauma, neurodegenerative and psychiatric diseases has significantly increased in recent years. Most of these diseases show multifactorial causes and several progression mechanisms. The search for a medication which positively interferes in these mechanisms and thereby changes the course of these diseases is of great scientific interest. The aim of the present review is to assess current literature on the possible role of methylene blue (MB) in the central nervous system due to the increasing number of citations in spite of the few articles available on the subject which suggest growing interest in the protective effects of MB on the central nervous system. Searches were performed on PubMed and Thomson Reuters Web of Knowledge. Therefore, we provide an overview of existing articles concerning: 1) MB actions; 2) MB neuroprotection and cardiac arrest; 3) MB neuroprotection and degenerative brain diseases; 4) MB neuroprotection and psychiatric diseases. PubMed was chosen because it holds the highest number of articles on the subject, Thomson Reuters was chosen due to its functionality which evaluates citations through analytic graphs. We conclude that MB has a beneficial effect and acts through many mechanisms and pathways of the central nervous system, being a potential alternative for the treatment of many neurodegenerative and psychiatric diseases.

Antidepressant Effects of a Single Dose of Ayahuasca in Patients With Recurrent Depression: A SPECT Study.

Ayahuasca is an Amazonian botanical hallucinogenic brew which contains dimethyltryptamine, a 5-HT2A receptor agonist, and harmine, a monoamine-oxidase A inhibitor. Our group recently reported that ayahuasca administration was associated with fast-acting antidepressive effects in 6 depressive patients. The objective of the present work was to assess the antidepressive potentials of ayahuasca in a bigger sample and to investigate its effects on regional cerebral blood flow. In an open-label trial conducted in an inpatient psychiatric unit, 17 patients with recurrent depression received an oral dose of ayahuasca (2.2 mL/kg) and were evaluated with the Hamilton Rating Scale for Depression, the Montgomery-Åsberg Depression Rating Scale, the Brief Psychiatric Rating Scale, the Young Mania Rating Scale, and the Clinician Administered Dissociative States Scale during acute ayahuasca effects and 1, 7, 14, and 21 days after drug intake. Blood perfusion was assessed eight hours after drug administration by means of single photon emission tomography. Ayahuasca administration was associated with increased psychoactivity (Clinician Administered Dissociative States Scale) and significant score decreases in depression-related scales (Hamilton Rating Scale for Depression, Montgomery-Åsberg Depression Rating Scale, Brief Psychiatric Rating Scale) from 80 minutes to day 21. Increased blood perfusion in the left nucleus accumbens, right insula and left subgenual area, brain regions implicated in the regulation of mood and emotions, were observed after ayahuasca intake. Ayahuasca was well tolerated. Vomiting was the only adverse effect recorded, being reported by 47% of the volunteers. Our results suggest that ayahuasca may have fast-acting and sustained antidepressive properties. These results should be replicated in randomized, double-blind, placebo-controlled trials.

Cognition in at-risk mental states for psychosis.

RATIONALE: The devastating nature of schizophrenia and treatment limitations have triggered a search for early detection methods to enable interventions to be implemented as soon as the first signs and symptoms appear. In this effort, several studies have investigated the cognitive functions in individuals regarded as being in at-risk mental states (ARMS) for psychosis. OBJECTIVE: Our aim was to make a systematic review of the literature regarding basic and social cognition in individuals in ARMS following the guidelines of the PRISMA statement. RESULTS: In general, the results of the 49 articles included in the review show that individuals in ARMS have pervasive cognitive deficits that seem to be greater in individuals who later convert to psychosis. CONCLUSIONS: Cognitive impairment can be detected in individuals considered to be in ARMS according to current classifications and may serve as a risk marker for psychotic conversion; however, the lack of standardized criteria to define ARMS and of homogeneous cognitive assessment methods hamper the generalization of findings from different studies.

Effects of nitric oxide-related compounds in the acute ketamine animal model of schizophrenia.

BACKGROUND: Better treatments for schizophrenia are urgently needed. The therapeutic use of the nitric oxide (NO)-donor sodium nitroprusside (SNP) in patients with schizophrenia has shown promising results. The role of NO in schizophrenia is still unclear, and NO modulation is unexplored in ketamine (KET) animal models to date. In the present study, we compared the behavioral effects of pre- and post-treatment with SNP, glyceryl trinitrate (GTN), and methylene blue (MB) in the acute KET animal model of schizophrenia. The present study was designed to test whether acute SNP, GTN, and MB treatment taken after (therapeutic effect) or before (preventive effect) a single KET injection would influence the behavior of rats in the sucrose preference test, object recognition task and open field. RESULTS: The results showed that KET induced cognitive deficits and hyperlocomotion. Long- term memory improvement was seen with the therapeutic GTN and SNP treatment, but not with the preventive one. MB pretreatment resulted in long-term memory recovery. GTN pre-, but not post-treatment, tended to increase vertical and horizontal activity in the KET model. Therapeutic and preventive SNP treatment consistently decreased KET-induced hyperlocomotion. CONCLUSION: NO donors - especially SNP - are promising new pharmacological candidates in the treatment of schizophrenia. In addition, we showed that the potential impact of NO-related compounds on KET-induced behavioral changes may depend on the temporal window of drug administration.

Paliperidone palmitate for refractory and clozapine-resistant schizophrenia.

This is a report on two cases of refractory schizophrenia and two cases of clozapine-resistant schizophrenia successful treated with paliperidone palmitate. To the authors' knowledge, this is the first report of the successful use of paliperidone palmitate in such patients.

Nitroprusside single-dose prevents the psychosis-like behavior induced by ketamine in rats for up to one week.

Recently, we found a rapid and long-lasting improvement of symptoms in schizophrenic patients on antipsychotics after a single four-hour infusion of sodium nitroprusside (SNP), a nitric oxide (NO) donor with a short half-life. This improvement persisted for up to 4weeks. Because these patients remained on antipsychotics after infusion of SNP was finished, the question arises about whether this improvement was due to SNP itself. We have now investigated whether SNP, alone, can produce preventive antipsychotic effects in rats treated with ketamine (KET). 56 adult rats divided into 7 groups were infused with SNP 4mg/kg, KET 25mg/kg, or saline as follows: group1 - saline, group2 - SNP, group3 - KET, group4 - KET 12h after SNP, group5 - KET 1day after SNP, group6 - KET 2days after SNP, and group7 - KET 1week after SNP. The animals were filmed in an open field arena for 30min and the videos were later analyzed by ANY-Maze software to measure activity and stereotypy. SNP significantly prevented the emergence of hyperactivity induced by KET when it was administered for up to 1week before KET, and prevented the emergence of stereotypies when it was administered for up to 1day before KET. These findings in rats, which have an even faster metabolic rate than humans, suggest that the long-lasting effects observed in our clinical trial with SNP in humans could have been due to SNP itself, and indicate for the first time that SNP may present preventive antipsychotic effects.