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"Schizophrenia - chemically induced"
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N-Acetylcysteine (NAC) in Schizophrenia Resistant to Clozapine: A Double-Blind, Randomized, Placebo-Controlled Trial Targeting Negative Symptoms
by
Liu, Dennis
,
Dean, Olivia M
,
Harris, Anthony
in
Acetylcysteine - pharmacology
,
Antipsychotic Agents - adverse effects
,
Australia
2022
Abstract
Background and Hypothesis
Clozapine is the most effective antipsychotic for treatment-resistant schizophrenia, yet a significant proportion of individuals on clozapine continue to experience disabling symptoms, despite being treated with an adequate dose. There is a need for adjunct treatments to augment clozapine, notably for negative and cognitive symptoms. One such potential agent is the glutathione precursor N-acetylcysteine (NAC).
Study Design
A randomized double-blind, multi-center, placebo-controlled trial for clozapine patients with enduring psychotic symptoms (n = 84) was undertaken to investigate the efficacy of adjunctive NAC (2 g daily) for negative symptoms, cognition and quality of life (QoL). Efficacy was assessed at 8, 24, and 52 weeks.
Study Results
NAC did not significantly improve negative symptoms (P = .62), overall cognition (P = .71) or quality of life (Manchester quality of life: P = .11; Assessment of quality of life: P = .57) at any time point over a 1-year period of treatment. There were no differences in reported side effects between the groups (P = .26).
Conclusions
NAC did not significantly improve schizophrenia symptoms, cognition, or quality of life in treatment-resistant patients taking clozapine. This trial was registered with “Australian and New Zealand Clinical Trials” on the 30 May, 2016 (Registration Number: ACTRN12615001273572).
Journal Article
Modulation of hippocampal activity in schizophrenia with levetiracetam: a randomized, double-blind, cross-over, placebo-controlled trial
by
McHugo, Maureen
,
Rogers, Baxter
,
Avery, Suzanne
in
Anticonvulsants - therapeutic use
,
Antipsychotics
,
Blood flow
2024
Hippocampal hyperactivity is a novel pharmacological target in the treatment of schizophrenia. We hypothesized that levetiracetam (LEV), a drug binding to the synaptic vesicle glycoprotein 2 A, normalizes hippocampal activity in persons with schizophrenia and can be measured using neuroimaging methods. Thirty healthy control participants and 30 patients with schizophrenia (28 treated with antipsychotic drugs), were randomly assigned to a double-blind, cross-over trial to receive a single administration of 500 mg oral LEV or placebo during two study visits. At each visit, we assessed hippocampal function using resting state fractional amplitude of low frequency fluctuations (fALFF), cerebral blood flow (CBF) with arterial spin labeling, and hippocampal blood-oxygen-level-dependent (BOLD) signal during a scene processing task. After placebo treatment, we found significant elevations in hippocampal fALFF in patients with schizophrenia, consistent with hippocampal hyperactivity. Additionally, hippocampal fALFF in patients with schizophrenia after LEV treatment did not significantly differ from healthy control participants receiving placebo, suggesting that LEV may normalize hippocampal hyperactivity. In contrast to our fALFF findings, we did not detect significant group differences or an effect of LEV treatment on hippocampal CBF. In the context of no significant group difference in BOLD signal, we found that hippocampal recruitment during scene processing is enhanced by LEV more significantly in schizophrenia. We conclude that pharmacological modulation of hippocampal hyperactivity in schizophrenia can be studied with some neuroimaging methods, but not others. Additional studies in different cohorts, employing alternate neuroimaging methods and study designs, are needed to establish levetiracetam as a treatment for schizophrenia.
Journal Article
L-Theanine adjunct to risperidone in the treatment of chronic schizophrenia inpatients: a randomized, double-blind, placebo-controlled clinical trial
by
A. Basti, Fatemeh
,
Khodaei Ardakani, Mohammad-Reza
,
Fattollahzadeh-Noor, Setareh
in
Antipsychotic Agents - adverse effects
,
Antipsychotics
,
Biomedical and Life Sciences
2023
Rationale
Inadequate responses to current schizophrenia treatments have accelerated research into novel therapeutic approaches.
Objectives
This study investigated the efficacy and tolerability of adjunctive L-theanine, an ingredient with neuroimmunomodulatory and neuroprotective properties, for chronic schizophrenia.
Methods
Eighty chronic schizophrenia inpatients were equally assigned to receive risperidone (6 mg/day) plus either L-theanine (400 mg/day) or matched placebo in this 8-week, randomized, parallel-group, double-blind, placebo-controlled trial. The participants were assessed using the Positive and Negative Syndrome Scale (PANSS) by recording the results of subscales at baseline and weeks 4 and 8 to measure treatment efficacy. Additionally, the participants were assessed for the Hamilton Depression Rating Scale (HDRS) and adverse events, including the Extrapyramidal Symptom Rating Scale (ESRS).
Results
Sixty patients, 30 in each group, were included in the analyses. All baseline demographic and clinical characteristics were comparable between the groups (
p
-values > 0.05). The reduction rates from baseline to endpoint in negative, general psychopathology, and total scores of PANSS were greater in the L-theanine group (
p
-values = 0.03, 0.01, and 0.04, respectively). Regarding general psychopathology scores, the reduction in the L-theanine group was also greater until week 4 (
p
-value < 0.01). The time × treatment interaction effect was significant on negative (
p
-value = 0.03), general psychopathology (
p
-value < 0.01), and total (
p
-value = 0.04) scores of PANSS, indicating additional improvements in the L-theanine group. The HDRS and side effects were comparable between the groups (
p
-values > 0.05).
Conclusions
L-Theanine adjunct to risperidone safely and tolerably outperformed adjunctive placebo for schizophrenia, and promising evidence indicated its effects on primary negative symptoms, which need to be scrutinized in further studies.
Trial registration
The study protocol was registered and published prospectively in the Iranian Registry of Clinical Trials (
http://www.irct.ir
; registration number: IRCT20090117001556N133) on 2020–12-12.
Journal Article
Reduced auditory evoked gamma-band response and schizophrenia-like clinical symptoms under subanesthetic ketamine
by
Curic Stjepan
,
Zöllner, Christian
,
Eichler, Lars
in
Cortex (cingulate)
,
Emotional behavior
,
Frequency dependence
2019
Abnormal gamma-band oscillations (GBO) have been frequently associated with the pathophysiology of schizophrenia. GBO are modulated by glutamate, a neurotransmitter, which is continuously discussed to shape the complex symptom spectrum in schizophrenia. The current study examined the effects of ketamine, a glutamate N-methyl-d-aspartate receptor (NMDAR) antagonist, on the auditory-evoked gamma-band response (aeGBR) and psychopathological outcomes in healthy volunteers to investigate neuronal mechanisms of psychotic behavior. In a placebo-controlled, randomized crossover design, the aeGBR power, phase-locking factor (PLF) during a choice reaction task, the Positive and Negative Syndrome Scale (PANSS) and the Altered State of Consciousness (5D-ASC) Rating Scale were assessed in 25 healthy subjects. Ketamine was applied in a subanaesthetic dose. Low-resolution brain electromagnetic tomography was used for EEG source localization. Significant reductions of the aeGBR power and PLF were identified under ketamine administration compared to placebo (p < 0.01). Source-space analysis of aeGBR generators revealed significantly reduced current source density (CSD) within the anterior cingulate cortex during ketamine administration. Ketamine induced an increase in all PANSS (p < 0.001) as well as 5D-ASC scores (p < 0.01) and increased response times (p < 0.001) and error rates (p < 0.01). Only negative symptoms were significantly associated with an aeGBR power decrease (p = 0.033) as revealed by multiple linear regression. These findings argue for a substantial role of the glutamate system in the mediation of dysfunctional gamma band responses and negative symptomatology of schizophrenia and are compatible with the NMDAR hypofunction hypothesis of schizophrenia.
Journal Article
Effect of add-on alpha lipoic acid on psychopathology in patients with treatment-resistant schizophrenia: a pilot randomized double-blind placebo-controlled trial
RationaleAlpha lipoic acid is known to reverse NMDA receptor hypofunction in addition to dopamine receptor blockade activity. It also enhances neurotrophic factors and has antioxidant potential. These properties combined together may be beneficial for treatment-resistant schizophrenia (TRS).ObjectivesThis study evaluates the effect of alpha lipoic acid (ALA) on psychopathological scores (positive, negative, cognitive), neurotrophic factors and oxidative stress in TRS.MethodsA pilot randomized double-blind placebo-controlled parallel design trial was conducted in 20 patients with TRS. After initial screening, participants were randomized into test (add-on ALA) and control (add-on placebo) groups. After recruitment, clinical evaluations with scale for assessment of positive symptoms and negative symptoms (SAPS and SANS), schizophrenia cognitive rating scale (SCoRS), UKU side effect rating scale were done. Serum levels of BDNF, MDA, and GSH were estimated. Patients were followed up for 8 weeks, and clinical and biochemical evaluations were repeated. Adherence to medication was evaluated at follow-up.ResultsA significantly greater improvement was found in SANS score in the test group when compared to control (Mann–Whitney U = 17.0; p = 0.021), whereas there was no significant improvement in SAPS score (Mann–Whitney U = 41.5; p = 0.780). A significant increase in BDNF levels was observed in the control group when compared to ALA (U = 20.0; p = 0.041). No significant differences were found between the test and control groups in serum MDA (U = 30.0; p = 0.221), serum GSH (U = 40.0; p = 0.683), and medication adherence rating scale (MARS) scores (U = 44.0; p = 0.934).ConclusionsALA supplementation improved psychopathology and decreased oxidative stress in patients with TRS. This study thus shows the potential of adjunctive ALA in TRS.Trial registrationThe study was prospectively registered in Clinical Trial Registry of India (CTRI/2020/03/023707 dated 02.03.2020).
Journal Article
Ketamine-Induced Modulation of the Thalamo-Cortical Network in Healthy Volunteers As a Model for Schizophrenia
by
Höflich, Anna
,
Saria, Alois
,
Kasper, Siegfried
in
Adult
,
Double-Blind Method
,
Excitatory Amino Acid Antagonists - administration & dosage
2015
Background:Schizophrenia has been associated with disturbances of thalamic functioning. In light of recent evidence suggesting a significant impact of the glutamatergic system on key symptoms of schizophrenia, we assessed whether modulation of the glutamatergic system via blockage of the N-methyl-d-aspartate (NMDA)-receptor might lead to changes of thalamic functional connectivity.Methods:Based on the ketamine model of psychosis, we investigated changes in cortico-thalamic functional connectivity by intravenous ketamine challenge during a 55-minute resting-state scan. Thirty healthy volunteers were measured with pharmacological functional magnetic resonance imaging using a double-blind, randomized, placebo-controlled, crossover design.Results:Functional connectivity analysis revealed significant ketamine-specific changes within the thalamus hub network, more precisely, an increase of cortico-thalamic connectivity of the somatosensory and temporal cortex.Conclusions:Our results indicate that changes of thalamic functioning as described for schizophrenia can be partly mimicked by NMDA-receptor blockage. This adds substantial knowledge about the neurobiological mechanisms underlying the profound changes of perception and behavior during the application of NMDA-receptor antagonists.
Journal Article
ATAD3B and SKIL polymorphisms associated with antipsychotic-induced QTc interval change in patients with schizophrenia: a genome-wide association study
2022
QTc interval prolongation is one of the most common antipsychotic-induced side effects which could lead to ventricular tachycardia or Torsade de Pointes, even cardiac arrest. There is very limited understanding on the genetic factors that associated with antipsychotic-induced QTc interval change. We conducted a genome-wide association study (GWAS) of antipsychotic-induced QTc interval change among patients with schizophrenia. A total of 2040 patients with schizophrenia were randomly assigned to six groups (olanzapine, risperidone, quetiapine, aripiprazole, ziprasidone, and first-generation antipsychotics; first-generation antipsychotics including haloperidol or perphenazine were also assigned randomly) and received 6-week antipsychotic treatment. We identified two novel loci (rs200050752 in
ATAD3B
and rs186507741 in
SKIL
) that were associated with antipsychotic-induced QTc interval change at a genome-wide significance level. The combination of polygenic risk score (PRS), based the GWAS of myocardial infarction from BioBank Japan project, and clinical data (sex, heart rate and QTc interval at baseline) could be applied to predict whether patients with schizophrenia have QTc interval prolongation (10 ms was applied as threshold,
P
< 0.001, area under the curve [AUC] was 0.797), especially for the first episode patients (
P
< 0.001, AUC was 0.872). We identified two loci located within genes related to mitochondrial function and cell growth and differentiation, which were both associated with schizophrenia and heart function. The combination of PRS and clinical data could predict whether patients with schizophrenia have the side effect of QTc interval prolongation, which could fundamentally guide the choice of antipsychotic in patients with schizophrenia, especially for the first-episode patients.
Journal Article
Low-Dose Ziprasidone in Combination with Sertraline for First-Episode Drug-Naïve Patients with Schizophrenia: a Randomized Controlled Trial
by
Xiu, Meihong
,
Wu, Fengchun
,
Liu, Jiahong
in
Antidepressants
,
Antipsychotic Agents - therapeutic use
,
Antipsychotics
2022
Many patients with schizophrenia (SCZ) discontinue antipsychotics, frequently due to dose-related multiple and severe adverse effects. We hypothesized that a low-dose ziprasidone plus sertraline would reduce serious side effects without affecting treatment efficacy. Therefore, this clinical trial was designed to investigate the efficacy, safety, and tolerability of adding sertraline to ziprasidone in order to substantially reduce ziprasidone dose and potential side effects in first-episode and drug-naive (FEDN) patients with SCZ. This 24-week randomized, double-blinded, controlled clinical trial randomly allocated 452 FEDN SCZ patients to receive a usual dose of ziprasidone (control group) or half the dose of ziprasidone in combination with sertraline (ZS group). Treatment outcome included the Positive and Negative Syndrome Scale (PANSS), the Hamilton Depression Rating Scale (HAMD), CGI-Severity (CGI-S) and the Personal and Social Performance Scale (PSP) at baseline and weeks 2, 4, 8, 12, and 24. Repeated measures ANCOVA showed significant treatment by time interactions on the PANSS general psychopathology and total scores, as well as CGI-S, HAMD, and PSP scores (all p < 0.05). Furthermore, the ZS group had greater reductions in PANSS general psychopathology, total scores, HAMD, and CGI-S (all p < 0.05) and greater increases in the PSP total score (p < 0.01) than the control group. Importantly, adverse effects were lower in the ZS than control group. The reduction in PANSS, CGI-S, or HAMD scores was not correlated with the increase in PSP. Sex and duration of disease predicted PSP improvement from baseline to week 24 in the ZS group. Our FEDN patients with SCZ were effectively treated for their psychotic and depressive symptoms while experiencing significantly fewer adverse effects using half the usual ziprasidone dose when combined with sertraline. ClinicalTrials.gov, NCT04076371.
Journal Article
Glutamatergic deficit and schizophrenia-like negative symptoms: new evidence from ketamine-induced mismatch negativity alterations in healthy male humans
by
Polomac, Nenad
,
Curic, Stjepan
,
Zöllner, Christian
in
Adult
,
Antidepressants
,
Brain - drug effects
2017
Targeting the N-methyl-d-aspartate receptor (NMDAR) is a major translational approach for treating negative symptoms of schizophrenia. Ketamine comprehensively produces schizophrenia-like symptoms, such as positive, cognitive and negative symptoms in healthy volunteers. The amplitude of the mismatch negativity (MMN) is known to be significantly reduced not only in patients with schizophrenia, but also in healthy controls receiving ketamine. Accordingly, it was the aim of the present study to investigate whether changes of MMN amplitudes during ketamine administration are associated with the emergence of schizophrenia-like negative symptoms in healthy volunteers.
We examined the impact of ketamine during an MMN paradigm with 64-channel electroencephalography (EEG) and assessed the psychopathological status using the Positive and Negative Syndrome Scale (PANSS) in healthy male volunteers using a single-blind, randomized, placebo-controlled crossover design. Low-resolution brain electromagnetic tomography was used for source localization.
Twenty-four men were included in our analysis. Significant reductions of MMN amplitudes and an increase in all PANSS scores were identified under the ketamine condition. Smaller MMN amplitudes were specifically associated with more pronounced negative symptoms. Source analysis of MMN generators indicated a significantly reduced current source density (CSD) under the ketamine condition in the primary auditory cortex, the posterior cingulate and the middle frontal gyrus.
The sample included only men within a tight age range of 20–32 years.
The MMN might represent a biomarker for negative symptoms in schizophrenia related to an insufficient NMDAR system and could be used to identify patients with schizophrenia with negative symptoms due to NMDAR dysfunction.
Journal Article
Effects of ketamine on brain function during response inhibition
by
Neumann, C.
,
Hurlemann, R.
,
Ettinger, U.
in
Administration, Intravenous
,
Adult
,
Biomedical and Life Sciences
2018
Introduction
The uncompetitive N-methyl-D-aspartate (NMDA) receptor (NMDAR) antagonist ketamine has been proposed to model symptoms of psychosis. Inhibitory deficits in the schizophrenia spectrum have been reliably reported using the antisaccade task. Interestingly, although similar antisaccade deficits have been reported following ketamine in non-human primates, ketamine-induced deficits have not been observed in healthy human volunteers.
Methods
To investigate the effects of ketamine on brain function during an antisaccade task, we conducted a double-blind, placebo-controlled, within-subjects study on
n
= 15 healthy males. We measured the blood oxygen level dependent (BOLD) response and eye movements during a mixed antisaccade/prosaccade task while participants received a subanesthetic dose of intravenous ketamine (target plasma level 100 ng/ml) on one occasion and placebo on the other occasion.
Results
While ketamine significantly increased self-ratings of psychosis-like experiences, it did not induce antisaccade or prosaccade performance deficits. At the level of BOLD, we observed an interaction between treatment and task condition in somatosensory cortex, suggesting recruitment of additional neural resources in the antisaccade condition under NMDAR blockage.
Discussion
Given the robust evidence of antisaccade deficits in schizophrenia spectrum populations, the current findings suggest that ketamine may not mimic all features of psychosis at the dose used in this study. Our findings underline the importance of a more detailed research to further understand and define effects of NMDAR hypofunction on human brain function and behavior, with a view to applying ketamine administration as a model system of psychosis. Future studies with varying doses will be of importance in this context.
Journal Article