BACKGROUND: Although clozapine is the most effective medication for treatment refractory schizophrenia, only 40% of people will meet response criteria. We therefore undertook a systematic review and meta-analysis of global literature on clozapine augmentation strategies.
METHODS: We systematically reviewed PubMed, PsycInfo, Embase, Cochrane Database, Chinese Biomedical Literature Service System and China Knowledge Resource Integrated Database for randomised control trials of augmentation strategies for clozapine resistant schizophrenia. We undertook pairwise meta-analyses of within-class interventions and, where possible, frequentist mixed treatment comparisons to differentiate treatment effectiveness Results: We identified 46 studies of 25 interventions. On pairwise meta-analyses, the most effective augmentation agents for total psychosis symptoms were aripiprazole (standardised mean difference: 0.48; 95% confidence interval: -0.89 to -0.07) fluoxetine (standardised mean difference: 0.73; 95% confidence interval: -0.97 to -0.50) and, sodium valproate (standardised mean difference: 2.36 95% confidence interval: -3.96 to -0.75). Memantine was effective for negative symptoms (standardised mean difference: -0.56 95% confidence interval: -0.93 to -0.20). However, many of these results included poor-quality studies. Single studies of certain antipsychotics (penfluridol), antidepressants (paroxetine, duloxetine), lithium and Ginkgo biloba showed potential, while electroconvulsive therapy was highly promising. Mixed treatment comparisons were only possible for antipsychotics, and these gave similar results to the pairwise meta-analyses.
CONCLUSIONS: On the basis of the limited data available, the best evidence is for the use of aripiprazole, fluoxetine and sodium valproate as augmentation agents for total psychosis symptoms and memantine for negative symptoms. However, these conclusions are tempered by generally short follow-up periods and poor study quality.
OBJECTIVE: The authors examined the safety and efficacy of antidepressants added to antipsychotic drugs in the treatment of schizophrenia.
METHOD: Multiple databases and previous publications were searched through June 2015 to identify all randomized controlled trials of any add-on antidepressants compared with placebo or no-treatment in schizophrenia. Depressive and negative symptoms (primary outcomes), overall symptoms, positive symptoms, side effects, exacerbation of psychosis, and responder rates were examined. Subgroup, meta-regression, and sensitivity analyses were performed, as well as investigations of publication bias and risk of bias.
RESULTS: Eighty-two randomized controlled trials with a total of 3,608 participants were included. Add-on antidepressants appeared more efficacious than controls for depressive symptoms (standardized mean difference: -0.25, 95% CI=-0.38 to -0.12), negative symptoms (standardized mean difference: -0.30, 95% CI=-0.44 to -0.16), overall symptoms (standardized mean difference: -0.24, 95% CI=-0.39 to -0.09), positive symptoms (standardized mean difference: -0.17, 95% CI=-0.33 to -0.01), quality of life (standardized mean difference: -0.32, 95% CI=-0.57 to -0.06), and responder rate (risk ratio: 1.52, 95% CI=1.29 to 1.78; number-needed-to-treat-to-benefit: 5, 95% CI=4 to 7). The effects on depressive and negative symptoms appeared more pronounced when minimum thresholds of these symptoms were inclusion criteria (standardized mean difference: -0.34, 95% CI=-0.58 to -0.09 and standardized mean difference: -0.58, 95% CI=-0.94 to -0.21, respectively). There were no significant differences between antidepressants and controls in terms of exacerbation of psychosis, premature discontinuation, and the number of participants with at least one adverse event. More patients taking add-on antidepressants suffered from abdominal pain, constipation, dizziness, and dry mouth.
CONCLUSIONS: Analysis of primary outcomes (depressive and negative symptoms) suggests small, beneficial effects of adjunctive antidepressants. It would appear that this augmentation can be accomplished with a low risk of exacerbation of psychosis and adverse effects. However, secondary and subgroup analyses should be interpreted cautiously and considered exploratory.
BACKGROUND: There is accumulating evidence that progressive changes in brain structure and function take place as schizophrenia unfolds. Among many possible candidates, oxidative stress may be one of the mediators of neuroprogression, grey matter loss and subsequent cognitive and functional impairment. Antioxidants are exogenous or endogenous molecules that mitigate any form of oxidative stress or its consequences. They may act from directly scavenging free radicals to increasing anti-oxidative defences. There is evidence that current treatments impact oxidative pathways and may to some extent reverse pro-oxidative states in schizophrenia. The existing literature, however, indicates that these treatments do not fully restore the deficits in antioxidant levels or restore levels of oxidants in schizophrenia. As such, there has been interest in developing interventions aimed at restoring this oxidative balance beyond the benefits of antipsychotics in this direction. If antioxidants are to have a place in the treatment of this serious condition, the relevant and up-to-date information should be available to clinicians and investigators.
OBJECTIVES: To evaluate the effect of antioxidants as add-on treatments to standard antipsychotic medication for improving acute psychotic episodes and core symptoms, and preventing relapse in people with schizophrenia.
SEARCH METHODS: We searched the Cochrane Schizophrenia Group's Study-Based Register of Trials which is based on regular searches of CINAHL, BIOSIS, AMED, Embase, PubMed, MEDLINE, PsycINFO, and registries of clinical trials. There are no language, time, document type, or publication status limitations for inclusion of records in the register. We ran this search in November 2010, and again on 8 January 2015. We also inspected references of all identified studies for further trials and contacted authors of trials for additional information.
SELECTION CRITERIA: We included reports if they were randomised controlled trials (RCTs) involving people with schizophrenia who had been allocated to either a substance with antioxidant potential or to a placebo as an adjunct to standard antipsychotic treatment.
DATA COLLECTION AND ANALYSIS: We independently extracted data from these trials and we estimated risk ratios (RR) or mean differences (MD), with 95% confidence intervals (CI). We assessed risk of bias for included studies and created a 'Summary of findings' table using GRADE.
MAIN RESULTS: The review includes 22 RCTs of varying quality and sample size studying Ginkgo biloba, N-acetyl cysteine (NAC), allopurinol, dehydroepiandrosterone (DHEA), vitamin C, vitamin E or selegiline. Median follow-up was eight weeks. Only three studies including a minority of the participants reported our a priori selected primary outcome of clinically important response. Short-term data for this outcome (measured as at least 20% improvement in scores on Positive and Negative Syndrome Scale (PANSS)) were similar (3 RCTs, n = 229, RR 0.77, 95% CI 0.53 to 1.12, low quality evidence). Studies usually reported only endpoint psychopathology rating scale scores. Psychotic symptoms were lower in those using an adjunctive antioxidant according to the PANSS ( 7 RCTS, n = 584, MD -6.00, 95% CI -10.35 to -1.65, very low quality evidence) and the Brief Psychiatric Rating Scale (BPRS) (8 RCTS, n = 843, MD -3.20, 95% CI -5.63 to -0.78, low quality evidence). There was no overall short-term difference in leaving the study early (16 RCTs, n = 1584, RR 0.73, 95% CI 0.48 to 1.11, moderate quality evidence), or in general functioning (2 RCTs, n = 52, MD -1.11, 95% CI -8.07 to 5.86, low quality evidence). Adverse events were generally poorly reported. Three studies reported useable data for 'any serious adverse effect', results were equivocal (3 RCTs, n = 234, RR 0.65, 95% CI 0.19 to 2.27, low quality evidence). No evidence was available for relapse, quality of life or service use.
AUTHORS' CONCLUSIONS: Although 22 trials could be included in this review, the evidence provided is limited and mostly not relevant to clinicians or consumers. Overall, although there was low risk of attrition and selective data reporting bias within the trials, the trials themselves were not adequately powered and need more substantial follow-up periods. There is a need for larger trials with longer periods of follow-up to be conducted. Outcomes should be meaningful for those with schizophrenia, and include measures of improvement and relapse (not just rating scale scores), functioning and quality of life and acceptability and, importantly, safety data.
BACKGROUND: Omega-3 fatty acids have shown promise as an adjunctive treatment for schizophrenia. However, efficacy across studies has been inconsistent. We conducted a meta-analysis of published controlled studies with the goal of detecting different efficacy profiles at various stages of schizophrenia.
METHODS: An online search was conducted for randomized, double-blind, placebo-controlled clinical trials, and a meta-analysis was conducted. RESULTS: Ten studies met the criteria for inclusion. Among patients in the prodromal phase of schizophrenia, omega-3 supplementation reduced psychotic symptom severity and lowered conversion rates to first-episode
psychosis. In patients with first-episode schizophrenia, omega-3 decreased nonpsychotic symptoms, required lower antipsychotic medication dosages, and improved early treatment response rates. Omega-3 had mixed results in patients with stable chronic schizophrenia, with only some patients experiencing significant benefits. Among patients with chronic schizophrenia, use of omega-3 fatty acids both by those experiencing acute exacerbations and those who had discontinued antipsychotic medications resulted in worsening of psychotic symptoms.
CONCLUSIONS: The data suggest that omega-3 fatty acids may be efficacious in reducing clinical symptoms for patients in the earlier stages of schizophrenia (prodrome and first episode), while producing mixed results for patients
in the chronic stages. Based on these results, omega-3 fatty acids would not
be recommended for acute exacerbations in patients with chronic schizophrenia
nor for relapse prevention after discontinuation of antipsychotics.
BACKGROUND: Many people with schizophrenia do not achieve a satisfactory treatment response with ordinary anti-psychotic drug treatment. In these cases, various add-on medications are used, among them lithium.
OBJECTIVES: To assess whether:1. Lithium alone is an effective treatment for schizophrenia, schizophrenia-like psychoses and schizoaffective psychoses; and2. Lithium augmentation of antipsychotic medication is an effective treatment for the same illnesses.
SEARCH METHODS: In July 2012, we searched the Cochrane Schizophrenia Group's Study-Based Register of Trials which is based on regular searches of CINAHL, BIOSIS, AMED, EMBASE, PubMed, MEDLINE, PsycINFO, and registries of clinical trials. This search was updated on January 20, 2015. For the first version of the review, we also contacted pharmaceutical companies and authors of relevant studies to identify further trials and obtain original participant data.
SELECTION CRITERIA: Randomised controlled trials (RCTs) of lithium compared with antipsychotics or placebo (or no intervention), whether as sole treatment or as an adjunct to antipsychotic medication, in the treatment of schizophrenia or schizophrenia-like psychoses or both.
DATA COLLECTION AND ANALYSIS: We extracted data independently. For dichotomous data, we calculated random-effects meta-analyses, risk ratios (RRs), and 95% confidence intervals (CI) on an intention-to-treat basis. For continuous data, we calculated mean differences (MD) and 95% confidence intervals. We used Grading of Recommendations Assessment, Development and Evaluation (GRADE) to create 'Summary of findings' tables and assessed risk of bias for included studies.
MAIN RESULTS: The update search in 2012 detected two further studies that met our inclusion criteria. We did not find any further studies that met our inclusion criteria in the 2015 search. This review now includes 22 studies, with a total of 763 participants (median mean age: 35 years, range: 26 to 72 years). Most studies were small, of short duration, and incompletely reported. As we detected a high risk of bias in many studies, the overall methodological quality of the included sample was rather low.Three small studies comparing lithium with placebo as the sole treatment showed no difference in any of the outcomes we analysed.In eight studies comparing lithium with antipsychotic drugs as the sole treatment, more participants in the lithium group left the studies early (eight RCTs; n = 270, RR 1.77, 95% CI 1.01 to 3.11, low quality evidence).Thirteen studies examined whether the augmentation of antipsychotic drugs with lithium salts is more effective than antipsychotic drugs alone. More participants who received lithium augmentation had a clinically significant response (10 RCTs; n = 396, RR 1.81, 95% CI 1.10 to 2.97, low quality evidence). However, this effect became non-significant when we excluded participants with schizoaffective disorders in a sensitivity analysis (seven RCTs; n = 272, RR 1.64, 95% CI 0.95 to 2.81), when we excluded non-double-blind studies (seven RCTs; n = 224, RR 1.82, 95% CI 0.84 to 3.96), or when we excluded studies with high attrition (nine RCTs; n = 355, RR 1.67, CI 0.93 to 3.00). The overall acceptability of treatment (measured by the number of participants leaving the studies early) was not significantly different between groups (11 RCTs; n = 320, RR 1.89, CI 0.93 to 3.84, very low quality evidence). Few studies reported on side effects. There were no significant differences, but the database is too limited to make any judgement in this regard. For example, there were no data on thyroid dysfunction and kidney problems - two major and well-known side effects of lithium.
AUTHORS' CONCLUSIONS: The evidence base for the use of lithium in schizophrenia is limited to 22 studies of overall low methodological quality. There is no randomised trial-based evidence that lithium on its own is an effective treatment for people with schizophrenia. There is some GRADE low quality evidence that augmentation of antipsychotics with lithium is effective, but the effects are not significant when more prone-to-bias open RCTs are excluded. Nevertheless, further large and well-designed trials are justified. These should concentrate on two target groups: (1) people with no affective symptoms, so that trialists can determine whether lithium has an effect on the core symptoms of schizophrenia, and (2) people with schizoaffective disorders for whom lithium is widely used in clinical practice, although there is no evidence to support this use.
OBJECTIVES: Existing 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.
METHODS: All 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.
RESULTS: 6503 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 RELEVANCE: Although some statistically significant effects on negative symptoms were evident, none reached the threshold for clinically significant improvement.
Limited options are available for clozapine-resistant schizophrenia and intolerable side effects of clozapine. We conducted a systematic review of randomized-controlled trials (RCTs) to determine the efficacy and safety of aripiprazole augmentation of clozapine for schizophrenia. Electronic databases searched included PubMed, Scopus, Cochrane Central Register of Controlled Trials, Cumulative Index to Nursing and Allied Health Literature (CINAHL), and Web of Science. This review synthesized the data of four short-term (8-24 weeks), placebo-controlled trials (N = 347). The overall relative risk (RR, 95% confidence interval) of discontinuation rates was not significantly different between groups (RR = 1.41, 95% CI = 0.78 to 2.56). The pooled standardized mean differences (SMDs, 95% CIs) (Z-test; number of study; I(2)-index) suggested trends of aripiprazole augmentation benefits on overall psychotic [-0.40 (-0.87 to 0.07) (n = 3; Z = 1.68, p = 0.09; I(2) = 68%)], positive [-1.05 (-2.39 to 0.29) (n = 3; Z = 1.54, p = 0.12; I(2) = 94%)], and negative [-0.36 (-0.77 to 0.05) (n = 3; Z = 1.74, p = 0.08; I(2) = 54%)] symptoms. Despite of no benefit on three cardiometabolic indices (i.e., fasting plasma glucose, triglyceride, and high-density lipoprotein), aripiprazole augmentation was superior for weight change with a mean difference (95% CI) of -1.36 kg (-2.35 to -0.36) (n = 3; Z = 2.67, p = 0.008; I(2) = 39%) and LDL-cholesterol with a mean difference of -11.06 mg/dL (-18.25 to -3.87) (n = 3; Z = 3.02, p = 0.003; I(2) = 31%). Aripiprazole augmentation was not correlated with headache and insomnia but significantly associated with agitation/akathesia (RR = 7.59, 95% CI = 1.43 to 40.18) (n = 3; Z = 2.38, p = 0.02; I(2) = 0%) and anxiety (RR = 2.70, 95% CI = 1.02 to 7.15) (n = 1; Z = 2.00, p = 0.05). The limited short-term data suggested that aripiprazole augmentation of clozapine can minimize the cardiometabolic risk, causes agitation/akathesia, and may be effective in attenuating psychotic symptoms.
Current psychopharmacological approaches to reduce psychotic phenomenology in schizophrenia are associated with adverse effects including extrapyramidal and metabolic side effects. In view of the emerging data on nutritional supplementation interventions in schizophrenia which are not entirely consistent, we aimed to review existent studies focusing on fatty acid and vitamin interventions and summarise current evidence on such nutritional supplementations in schizophrenia. We searched the digital databases (ScienceDirect, Scopus, SpringerLINK, PubMed/Medline) for relevant studies pertaining to fatty acid and vitamin supplementation interventions in the management of psychotic symptoms in schizophrenia up to February 2015. Overall, there were more studies conducted on fatty acid over vitamin supplementations in patients with schizophrenia. There were more positive findings in support of fatty acid supplementation compared with vitamin supplementation in the context of specific intervention features (dose of nutrient supplementation, single versus combination nutritional interventions, specific antipsychotic), subject features (older age, long duration of illness, baseline polyunsaturated fatty acid levels) and clinical outcomes (improvements of psychotic symptoms and/or extrapyramidal side effects from antipsychotics). However, investigations of both supplementation modalities were limited by relatively small study sample sizes, short study duration, which precluded further segmentation of impact on more diverse patient subtypes and symptom profiles. Future studies may consider examining larger samples over a longer time period, recruiting younger subjects with shorter duration of illness, examination of different clinical features including specific cognitive domains, and use of single versus combination nutritional interventions.
Context: Despite advances made in treating the positive symptoms of schizophrenia, treatment of negative symptoms remains an unmet therapeutic need. Adjunctive mirtazapine has shown promise for treatment of negative symptoms in several small clinical trials. Objective: To assess the efficacy of mirtazapine as an adjunctive treatment of negative symptoms in patients with chronic schizophrenia via meta-analysis. Data Sources: A systematic literature review of articles in English and Spanish was conducted in November 2011 by searching PubMed, the Cochrane Library, the Clinical Trial Registry of the NIH, and SIGLE (System for Grey Literature in Europe). Free text search terms for PubMed were "schizophrenia," "negative symptoms" and "mirtazapine." Publication date was not a limitation. Study Selection: Studies of people with schizophrenia/schizoaffective disorder were included in the meta-analysis if they were randomized, double-blind, and used the Positive and Negative Syndrome Scale (PANSS) as an outcome measure. Nine studies were initially identified. Five studies were included in the meta-analysis; 1 study was excluded for not using the PANSS, 3 were excluded as representing duplicate publications and open-label phases of one of the selected randomized control trials. Studies varied in the quality of their selection for participants with primary negative symptoms. Results: Three of the 5 studies showed significant improvement in negative symptoms individually. The overall analysis showed improvement in negative symptoms with an effect size of 1.00 (0.084-1.918), which was statistically significant (p=0.032). Data from the negative symptoms subscale of the PANSS from 169 subjects was used in a forest plot to illustrate the relative strength of treatment effects. The variation in standard median deviation (SMD) attributable to heterogeneity was 27.35%, indicating a high degree of heterogeneity. Conclusions: This meta-analysis supports the hypothesis that adding mirtazapine to treatment with antipsychotics can improve negative symptoms in schizophrenia. However, additional studies with more stringent negative symptom selection criteria and homogeneous use of antipsychotics are needed.
Objectives. This study was conducted to review systematically adjunctive treatments for weight reduction in patients with schizophrenia and compare efficacies of clinical trials through meta-analysis, so as to provide effective clinical guideline regarding weight control for patients taking atypical antipsychotics. Methods. Candidate clinical trials were identified through searching the Cochrane Central Register of Controlled Trials, PubMed, and PsycINFO. Fourteen randomized clinical trials were included for systematic review and meta-analysis from 132 potential trials. The Comprehensive Meta-Analysis version 2 was used for meta-analysis. Results. Difference in means and significances from meta-analyses regarding weight control by adjunctive treatments showed that topiramate, aripiprazole, or sibutramine was more effective than metformin or reboxetine. Psychiatric evaluations did not show statistically significant changes between treatment groups and placebo groups except topiramate adjunctive treatments. Adverse effects regarding adjunctive therapies were tolerable and showed statistically no significances compared to control groups. Conclusion. Though having several reports related to exacerbation of psychiatric symptoms, topiramate and aripiprazole are more efficacious than other medications in regard to weight reduction and less burden of critical adverse effects as well as being beneficial for clinical improvement.
Although clozapine is the most effective medication for treatment refractory schizophrenia, only 40% of people will meet response criteria. We therefore undertook a systematic review and meta-analysis of global literature on clozapine augmentation strategies.
METHODS:
We systematically reviewed PubMed, PsycInfo, Embase, Cochrane Database, Chinese Biomedical Literature Service System and China Knowledge Resource Integrated Database for randomised control trials of augmentation strategies for clozapine resistant schizophrenia. We undertook pairwise meta-analyses of within-class interventions and, where possible, frequentist mixed treatment comparisons to differentiate treatment effectiveness Results: We identified 46 studies of 25 interventions. On pairwise meta-analyses, the most effective augmentation agents for total psychosis symptoms were aripiprazole (standardised mean difference: 0.48; 95% confidence interval: -0.89 to -0.07) fluoxetine (standardised mean difference: 0.73; 95% confidence interval: -0.97 to -0.50) and, sodium valproate (standardised mean difference: 2.36 95% confidence interval: -3.96 to -0.75). Memantine was effective for negative symptoms (standardised mean difference: -0.56 95% confidence interval: -0.93 to -0.20). However, many of these results included poor-quality studies. Single studies of certain antipsychotics (penfluridol), antidepressants (paroxetine, duloxetine), lithium and Ginkgo biloba showed potential, while electroconvulsive therapy was highly promising. Mixed treatment comparisons were only possible for antipsychotics, and these gave similar results to the pairwise meta-analyses.
CONCLUSIONS:
On the basis of the limited data available, the best evidence is for the use of aripiprazole, fluoxetine and sodium valproate as augmentation agents for total psychosis symptoms and memantine for negative symptoms. However, these conclusions are tempered by generally short follow-up periods and poor study quality.
