Antipsychotics for negative and positive symptoms of schizophrenia: dose-response meta-analysis of randomized controlled acute phase trials.
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ABSTRACT:
SUBMITTER: Sabe M
PROVIDER: S-EPMC8438046 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:BackgroundNegative symptoms are a core aspect of psychopathology in schizophrenia. Currently available pharmacological agents have proven minimally efficacious for remediating negative symptoms. A promising treatment avenue is the intranasal administration of the neuropeptide oxytocin. However, there have been inconsistencies in effects of oxytocin on negative symptoms throughout the literature, and factors leading to inconsistent effects are unclear.MethodsWe conducted a systematic review and meta-analysis of randomized clinical trials to compare the effectiveness of oxytocin with placebo for the treatment of negative symptoms and determine moderators of treatment effect. Random effects meta-analyses and dose-response meta-analysis were performed on mean changes in negative symptoms.ResultsIn an initial analysis of all 9 identified randomized clinical trials, intranasal oxytocin showed no significant effect on negative symptoms. For higher doses (>40-80 IU), a beneficial effect on negative symptoms was found with a moderate effect size, but this effect disappeared after exclusion of 1 outlier study. The dose-response meta-analysis predicted that higher doses of oxytocin may be more efficacious for negative symptoms. For positive symptoms, no beneficial effect of oxytocin was found in the main meta-analysis, but the dose-response meta-analysis suggested a potential advantage of higher doses.ConclusionsThe present results show no consistent beneficial effect of intranasal oxytocin for the treatment of negative and positive symptoms. The dose-response meta-analysis does not allow drawing any firm conclusions but suggests that high doses of intranasal oxytocin may be more efficacious. If future studies are conducted, an effort to reach adequate CNS concentrations for a sufficient duration is required.
| S-EPMC8378078 | biostudies-literature
Project description:BACKGROUND:Evidence suggests that genetic factors may influence both schizophrenia (Scz) and its clinical presentation. In recent years, genome-wide association studies (GWAS) have demonstrated considerable success in identifying risk loci. Detection of "modifier loci" has the potential to further elucidate underlying disease processes. METHODS:We performed GWAS of empirically derived positive and negative symptom scales in Irish cases from multiply affected pedigrees and a larger, independent case-control sample, subsequently combining these into a large Irish meta-analysis. In addition to single-SNP associations, we considered gene-based and pathway analyses to better capture convergent genetic effects, and to facilitate biological interpretation of these findings. Replication and testing of aggregate genetic effects was conducted using an independent European-American sample. RESULTS:Though no single marker met the genome-wide significance threshold, genes and ontologies/pathways were significantly associated with negative and positive symptoms; notably, NKAIN2 and NRG1, respectively. We observed limited overlap in ontologies/pathways associated with different symptom profiles, with immune-related categories over-represented for negative symptoms, and addiction-related categories for positive symptoms. Replication analyses suggested that genes associated with clinical presentation are generalizable to non-Irish samples. CONCLUSIONS:These findings strongly support the hypothesis that modifier loci contribute to the etiology of distinct Scz symptom profiles. The finding that previously implicated "risk loci" actually influence particular symptom dimensions has the potential to better delineate the roles of these genes in Scz etiology. Furthermore, the over-representation of distinct gene ontologies/pathways across symptom profiles suggests that the clinical heterogeneity of Scz is due in part to complex and diverse genetic factors.
| S-EPMC4753595 | biostudies-literature
Project description:BackgroundIt remains unknown as to whether the antipsychotic dose needed for the acute-phase treatment of schizophrenia is also necessary for relapse prevention.AimTo compare the efficacy between standard dose [(World Health Organization daily defined dose (DDD)] vs low dose (?50% to <1 DDD) or very low dose (<50% DDD) for relapse prevention in schizophrenia.Data sourceDouble-blind, randomized, controlled trials with a follow-up duration of ?24 weeks, including ?2 dosage groups of the same antipsychotic drug for relapse prevention in schizophrenia, were searched using MEDLINE, the Cochrane Central Register of Controlled Trials, and EMBASE (last search: August 2009).Data extractionData on overall treatment failure, hospitalization, relapse, and dropouts due to side effects were extracted and combined in a meta-analysis.Data synthesisThirteen studies with 1395 subjects were included in this meta-analysis. Compared with the standard-dose treatment, the low-dose therapy did not show any statistically significant difference in overall treatment failure or hospitalization, while the standard dose showed a trend-level (P = .05) superiority in risk of relapse. The very low-dose group was inferior to the standard-dose group in all efficacy parameters. No significant difference was found in the rate of dropouts due to side effects between either standard dose vs low dose or very low dose.ConclusionsAlthough antipsychotic treatment with ?50% to <1 DDD may be as effective as standard-dose therapy, there are insufficient clinical trial data to draw firm conclusions on standard- vs low-dose maintenance antipsychotic therapy for schizophrenia.
| S-EPMC3122280 | biostudies-literature
Project description:ObjectivesExisting treatments for schizophrenia can improve positive symptoms, but it is unclear if they have any impact on negative symptoms. This meta-analysis was conducted to assess the efficacy of available treatments for negative symptoms in schizophrenia.MethodsAll randomized-controlled trials of interventions for negative symptoms in schizophrenia until December 2013 were retrieved; 168 unique and independent placebo-controlled trials were used. Negative symptom scores at baseline and follow-up, duration of illness, doses of medication, type of interventions, and sample demographics were extracted. Heterogeneity was addressed with the I (2) and Q statistic. Standardized mean difference in values of the Negative Symptom Rating Scale used in each study was calculated as the main outcome measure.Results6503 patients in the treatment arm and 5815 patients in the placebo arm were included. No evidence of publication biases found. Most treatments reduced negative symptoms at follow-up relative to placebo: second-generation antipsychotics: -0.579 (-0.755 to -0.404); antidepressants: -0.349 (-0.551 to -0.146); combinations of pharmacological agents: -0.518 (-0.757 to -0.279); glutamatergic medications: -0.289 (-0.478 to -0.1); psychological interventions: -0.396 (-0.563 to -0.229). No significant effect was found for first-generation antipsychotics: -0.531 (-1.104 to 0.041) and brain stimulation: -0.228 (-0.775 to 0.319). Effects of most treatments were not clinically meaningful as measured on Clinical Global Impression Severity Scale.Conclusions and relevanceAlthough some statistically significant effects on negative symptoms were evident, none reached the threshold for clinically significant improvement.
| S-EPMC4466178 | biostudies-literature
Project description:Schizophrenia is the eighth leading cause of disability worldwide in people aged 15-44 years. Before antidopaminergic antipsychotics were introduced in the 1950s, no effective medications existed for the treatment of schizophrenia. This review summarizes key meta-analytic findings regarding antipsychotic efficacy in the acute treatment of schizophrenia, including clozapine in treatment-resistant patients. In the most comprehensive meta-analysis of randomized controlled trials conducted in multi-episode schizophrenia, antipsychotics outperformed placebo regarding total symptoms, positive symptoms, negative symptoms, depressive symptoms, quality of life and social functioning. Amongst these outcomes, the standardized mean difference for overall symptoms was largest, that is, 0.47 (95% credible interval = 0.42-0.51), approaching a medium effect size, being reduced to 0.38 when publication bias and small-trial effects were accounted for. A comparison of two meta-analyses indicated that first-episode patients, compared with multi-episode patients, were more likely to have at least minimal treatment response [?20% Positive and Negative Syndrome Scale (PANSS)/Brief Psychiatric Rating Scale (BPRS) score reduction: 81% versus 51%] and good response (?50% PANSS/BPRS score reduction: 52% versus 23%). In multi-episode schizophrenia, no response or worsening after 2 weeks of a therapeutic antipsychotic dose was highly predictive of not achieving a good response at endpoint (median treatment = 6 weeks: specificity = 86%; positive predictive value = 90%), suggesting a change in treatment should be considered in such cases. In first-episode psychosis, adequately dosed antipsychotic treatment trials for more than 2 weeks are recommended before using no response or worsening as a decision point for aborting a given antipsychotic. In clearly defined treatment-resistant schizophrenia, clozapine generally outperformed other antipsychotics, especially when dosed appropriately (target = 3-6 months' duration; trough clozapine level ?350-400 ?g/L) with a response rate (?20% PANSS/BPRS) of 33% by 3 months of treatment. High antipsychotic doses and psychotropic combinations are unlikely to be superior to standard doses of antipsychotic monotherapy. Acute antipsychotic efficacy in schizophrenia depends on the targeted symptom domain (greater efficacy: total and positive symptoms, lesser efficacy: negative symptoms, depressive symptoms, social functioning and quality of life). Greater antipsychotic efficacy is associated with higher total baseline symptom severity, treatment-naïveté/first-episode status, shorter illness duration, and trials that are nonindustry sponsored and that have a lower placebo effect. The heterogeneity of antipsychotic response across individuals and key symptom domains, the considerable degree of nonresponse/treatment resistance in multi-episode patients, and the adverse effect potential of antipsychotics are major limitations, underscoring the need to develop new medications for the treatment of schizophrenia. Drug development should include matching patient subgroups, which are identified by means of clinical and biomarker variables, to mechanisms of action of novel medications, targeting specific symptom domains, and investigating mechanisms of action other than dopaminergic blockade.
| S-EPMC6180374 | biostudies-other
Project description: Not available
| S-EPMC9289703 | biostudies-literature
Project description:We conducted a meta-regression analysis of all double-blind, randomized, placebo-controlled clinical trials (DBRCTs) reporting effects of drug and placebo on negative symptoms in people with stable schizophrenia and predominant or prominent negative symptoms to assess predictors of placebo response in these individuals. We used Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines for systematic reviews and meta-analyses to conduct a systematic literature search to identify DBRCTs assessing treatment efficacy on negative symptoms, as primary outcome, in patients with stable schizophrenia and predominant or prominent negative symptoms. We used Cohen's d, with 95% CIs, as the effect size measure for placebo response, based on negative symptom change scores from baseline to endpoint (range 4 to 24 wk) in the placebo-treated group. We included 18 DBRCTs from 17 publications, assessing the effect of 13 drugs vs placebo on negative symptoms and comprising 998 patients, in the meta-regression analyses. Overall, drugs showed greater efficacy than placebo in reducing negative symptoms, with small effect size (Cohen's d: 0.208, P = .020). Placebo response was significant (P < .001) and clinically relevant (Cohen's d: 2.909), but there was significant heterogeneity and high risk of publication bias. Multivariable meta-regression analyses showed that larger numbers of arms in the trial, larger numbers of study sites and industry sponsorship were significant moderators of placebo response in this population. Our results suggest that some clinical trial design and operational factors affect the level of placebo response in such studies, thus highlighting the need for designs better suited to assess these outcomes.
| S-EPMC6293224 | biostudies-literature
Project description:INTRODUCTION:There is rising awareness that we need multidisciplinary approaches integrating psychological treatments for schizophrenia, but a comprehensive evidence based on their relative efficacy is lacking. We will conduct a network meta-analysis (NMA), integrating direct and indirect comparisons from randomised controlled trials (RCTs) to rank psychological treatments for schizophrenia according to their efficacy, acceptability and tolerability. METHODS AND ANALYSIS:We will include all RCTs comparing a psychological treatment aimed at positive symptoms of schizophrenia with another psychological intervention or with a no treatment condition (waiting-list and treatment as usual). We will include studies on adult patients with schizophrenia, excluding specific subpopulations (eg, first-episode patients or patients with psychiatric comorbidities). Primary outcome will be the change in positive symptoms on a published rating scale. Secondary outcomes will be acceptability (dropout), change in overall and negative symptoms of schizophrenia, response, relapse, adherence, depression, quality of life, functioning and adverse events. Published and unpublished studies will be sought through database searches, trial registries and websites. Study selection and data extraction will be conducted by at least two independent reviewers. We will conduct random-effects NMA to synthesise all evidences for each outcome and obtain a comprehensive ranking of all treatments. NMA will be conducted in Stata and R within a frequentist framework. The risk of bias in studies will be evaluated using the Cochrane Risk of Bias tool and the credibility of the evidence will be evaluated using an adaptation of the Grading of Recommendations Assessment, Development and Evaluation framework to NMA, recommended by the Cochrane guidance. Subgroup and sensitivity analyses will be conducted to assess the robustness of the findings. ETHICS AND DISSEMINATION:No ethical issues are foreseen. Results from this study will be published in peer-reviewed journals and presented at relevant conferences. PROSPERO REGISTRATION NUMBER:CRD42017067795.
| S-EPMC5857696 | biostudies-literature
Project description:Autism spectrum disorder (ASD) and schizophrenia (SZ) are heterogenous neurodevelopmental disorders that overlap in symptom presentation. The purpose of this study was to specify overlapping symptom domains and to identify symptoms that can reliably differentiate adults with ASD (n = 53), SZ (n = 39), and typical development (TD; n = 40). All participants regardless of diagnosis were administered gold-standard diagnostic assessments of ASD and SZ characteristics including the Autism Diagnostic Observation Schedule (ADOS-2) and the Positive and Negative Syndrome Scale (PANSS). Sensitivity and specificity of the ADOS were assessed using diagnostic cut-off scores. The degree of symptom overlap on these measures between participant groups was analyzed using Analyses of Variance (ANOVAs), Receiver Operating Characteristic (ROC) Curves, and Analyses of Covariance (ANCOVAs) to control for group differences in IQ and sex distributions. The ADOS reliably discriminated ASD and TD adults, but there was a high rate of "false positives" in SZ patients who did not meet the DSM-5 criteria for ASD. To identify the reasons for low specificity in the SZ sample, we categorized ASD and SZ symptoms into 'positive' (presence of atypical behaviors) and 'negative' (absence of typical behaviors) symptoms. ASD and SZ groups overlapped on negative symptoms largely related to the absence of typical social and communicative behaviors, whereas disorder-specific positive symptoms differentiated ASD and SZ. For example, those with ASD scored higher on restricted and repetitive behaviors and stereotyped language, whereas those with SZ scored higher on psychotic symptoms such as delusions and hallucinations. These results suggest that, when making a differential diagnosis between ASD and SZ, clinicians may benefit from focusing on the presence or absence of positive ASD and SZ symptoms. Standardized measures to classify ASD symptoms into positive and negative symptoms have not yet been developed but represent a potentially viable clinical tool.
| S-EPMC7301837 | biostudies-literature
Project description:Little is known regarding optimal antipsychotic doses in the acute phase of schizophrenia. The aim of the present study was to employ the concept of minimum effective dose (MED) in examining efficacy and tolerability within this population. MED was identified for each antipsychotic through a previous systematic review. We then identified double-blind placebo-controlled randomized trials that involved fixed-dose antipsychotic monotherapy in acute schizophrenia and compared the identified MED vs higher doses of the same oral antipsychotic. Studies were selected from a recent meta-analysis examining dose-response relationship of second-generation antipsychotics and haloperidol. We extracted the data on study discontinuation, psychopathology, extrapyramidal symptoms, and treatment-emergent adverse events. For each antipsychotic, we conducted a meta-analysis to compare outcomes between MED and 2-fold MED, and MED and 3-fold MED. A total of 26 studies involving 5618 patients were included in the meta-analysis. In terms of study discontinuation, significant differences were found in study discontinuation due to lack of efficacy between MED and higher doses, in favor of 2-fold and 3-fold MEDs. Regarding psychopathology, both 2-fold and 3-fold MEDs were superior to MED for total and positive symptom scores. As for side effects, 2-fold MED proved inferior to MED for parkinsonism scores and diarrhea, whereas 3-fold MED was inferior for akathisia, somnolence, and vomiting. Findings suggest that clinicians can dose an antipsychotic at 2-fold or 3-fold MED for patients with acute schizophrenia but should closely monitor side effects.
| S-EPMC7707077 | biostudies-literature