Pharmacological augmentation strategies for schizophrenia patients with insufficient response to clozapine: a quantitative literature review

Optimizing antidepressant and clozapine co-prescription in clinical practice: A systematic review and expert recommendations

OBJECTIVES

To synthesize the information relevant for clinical practice on clozapine-antidepressant co-prescription concerning pharmacokinetic drug-drug interactions (DDI), adverse drug reactions (ADRs) associated with the co-prescription, antidepressant add-on for clozapine-resistant symptoms and antidepressant add-on for clozapine-induced ADRs.

METHODS

Articles were identified with MEDLINE, Web of Sciences and PsycINFO search from inception through April 2023. Data were synthesized narratively.

RESULTS

ADRs are most often induced by the co-prescription of antidepressants that inhibit CYP enzymes (fluvoxamine, fluoxetine, paroxetine). Fluvoxamine add-on is hazardous because of its potent inhibition of clozapine metabolism and has few indications (lowering daily number of clozapine tablets, reducing norclozapine-induced metabolic disturbances and other dose-dependent clozapine-induced ADRs). ADR frequency may be reduced by therapeutic drug monitoring and knowledge of other factors impacting clozapine metabolism (pneumonia, inflammation, smoking, etc.). Improvement of negative symptoms is the most documented beneficial effect of antidepressant add-on for clozapine-resistant psychotic symptoms. The add-on antidepressant should be chosen according to its safety profile regarding DDI with clozapine: antidepressants inhibiting clozapine metabolism or increasing the anticholinergic load should be avoided. Other indications of antidepressant add-on (affective or obsessive compulsive symptoms, sialorrhea, and enuresis) are poorly documented.

CONCLUSION

Antidepressant add-on to clozapine is associated with potential benefits in clozapine users as this strategy may contribute to reduce the burden of clozapine-resistant symptoms or of clozapine-induced ADRs. Further studies are needed to determine whether antidepressant add-on can reduce the risk of clozapine discontinuation.

Optimizing co-prescription of clozapine and antiseizure medications: a systematic review and expert recommendations for clinical practice

INTRODUCTION

Antiseizure medication (ASM) add-on to clozapine may be efficient to target clozapine-resistant mood or psychotic symptoms or clozapine-related adverse drug reactions (ADR) such as seizures. We aimed to synthesize the information relevant for clinical practice on the risks and benefits of clozapine-ASM co-prescription.

AREAS COVERED

Articles were identified with MEDLINE, Web of Sciences and PsycINFO search from inception through October 2023. The review was restricted to ASM with mood-stabilizing properties or with potential efficacy for resistant psychotic symptoms (valproate (VPA), lamotrigine, topiramate, carbamazepine, oxcarbazepine).

EXPERT OPINION

VPA add-on to clozapine is associated with a high risk of serious ADR (myocarditis, neutropenia, pneumonia) mostly explained by complex time-dependent drug-drug interactions. The initial inhibitory effects on clozapine metabolism require slow titration to avoid immuno-allergic reactions. After the titration period, VPA has mainly inductive effects on clozapine metabolism that are more marked in smokers requiring therapeutic drug monitoring. Lamotrigine and topiramate add-on may be recommended as the first-line treatment for clozapine-related seizures, but there is limited evidence regarding the efficacy of this strategy for clozapine-resistant psychotic symptoms. Carbamazepine should not be co-prescribed with clozapine because of its potential for agranulocytosis and for inducing clozapine metabolism.

Long-Acting Injectable Second-Generation Antipsychotics in Seriously Ill Patients with Schizophrenia: Doses, Plasma Levels, and Treatment Outcomes

This research studies the dose-plasma level (PL) relationship of second-generation antipsychotics, together with the treatment outcomes achieved, in seriously ill people with schizophrenia. An observational, prospective, one-year follow-up study was carried out with patients (N = 68) with severe schizophrenia treated with paliperidone three-month (PP3M) or aripiprazole one-month (ARIM). Participants were divided into standard-dose or high-dose groups. PLs were divided into "standard PL" and "high PL" (above the therapeutic reference range, TRR) groups. The dose/PL relationship, and severity, hospitalizations, tolerability, compliance, and their relationship with doses and PLs were evaluated. There was no clear linear relationship between ARIM or PP3M doses and the PLs achieved. In half of the subjects, standard doses reached PLs above the TRR. The improvements in clinical outcomes (decrease in clinical severity and relapses) were related to high PLs, without worse treatment tolerability or adherence. All participants remained in the study, regardless of dose or PL. Clinical severity and hospitalizations decreased significantly more in those patients with high PLs. Considering the non-linear dose-PL relationship of ARIM and PP3M in people with severe schizophrenia, PLs above the TRR are linked to better treatment outcomes, without worse tolerability. The need in a notable number of cases for high doses to reach those effective PLs is highlighted.

Plasmatic Levels and Response to Variable Doses of Monthly Aripiprazole and Three-Month Paliperidone in Patients with Severe Schizophrenia. Treatment Adherence, Effectiveness, Tolerability, and Safety

Introduction

There is a need when optimizing antipsychotic treatment to know the plasmatic levels (PLs) achieved with the different doses and their relationship with effectiveness and toxicity, especially in patients with poor clinical progress. This study investigates the dose-PL-response relationship of monthly aripiprazole (AOM) and three-month paliperidone (PP3M).

Methods

Observational, 52-week prospective study of patients with severe schizophrenia (CGI-S ≥ 5) treated with PP3M or AOM for at least one year before their inclusion in the study (N=68). Dose-PL relationship was determined. Subjects were included in standard-dose and high-dose (above labeled) and standard/therapeutic range-PLs and high-PLs (above range) groups. Treatment adherence, effectiveness (hospitalizations, severity), tolerability and safety were assessed. PLs and clinical response were evaluated.

Results

No clear linear relationship was found between doses and PLs. In a considerable number of cases, standard doses achieved PLs above the therapeutic range. A significant clinical improvement was related to high PLs, without less safety, tolerability, or treatment compliance being involved. Clinical severity decreased more frequently in patients who received high doses and reached high PLs. Hospital admissions decreased significantly in those patients with high PLs.

Conclusion

Taking into account the absence of a linear relationship between doses and PLs, the effectiveness in people with severe schizophrenia of AOM and PP3M depends on reaching high PLs, achieved with high doses, but also with standard doses in some cases, without leading to worse treatment tolerability, safety, or adherence.

The Use of Second-Generation Antipsychotics in Patients with Severe Schizophrenia in the Real World: The Role of the Route of Administration and Dosage-A 5-Year Follow-Up

To assess the impact of the route of administration and doses of second-generation antipsychotics (SGAs) on treatment adherence, hospital admissions, and suicidal behaviour in patients with severe schizophrenia (Clinical Global Impression−Severity−CGI-S ≥ 5), we implemented an observational 5-year follow-up study. A total of 37.5% of the patients on oral antipsychotics (Aps) and 11.5% of those on long-acting injectables (LAIs) abandoned the treatment (p < 0.001). There were no differences in treatment discontinuation between the LAI-AP standard and high-dose groups. A total of 28.1% of the patients on oral Aps had at least one hospitalisation, as well as 13.1% of patients on LAIs (p < 0.001). There were fewer hospitalisations of patients on LAIs in the high-dose group (p < 0.05). Suicide attempts were recorded for 18% of patients on oral Aps but only for 4.6% of patients on LAIs (p < 0.001). No differences were found between the dosage groups on LAIs. Tolerability was good for all Aps and somewhat better for LAIs than oral Aps in terms of side effects (p < 0.05). There were no differences between the standard and high-dose groups. More patients discontinued treatment due to side effects in the oral AP group (p < 0.01). LAI SGA treatment was more effective than oral AP in terms of adherence and treatment outcomes for managing people with severe schizophrenia. Moreover, significant improvements were found that favour high-dose LAI SGA treatment for some of these patients. This study highlights the need to consider LAI antipsychotics and high-dose strategies for patients with severe schizophrenia.

Impact of medications, mood state, and electrode placement on ECT outcomes in treatment-refractory psychosis

BACKGROUND

Treatment-refractory psychosis (TRP) is a significant clinical challenge. While clozapine is frequently effective, alternate or augmentation strategies are often necessary. Evidence supports effectiveness of electroconvulsive therapy (ECT), but questions remain about optimal treatment parameters and impacts of concomitant pharmacotherapy.

OBJECTIVE

/Hypothesis: To analyze the impact of clozapine, anticonvulsant medication, mood state, and ECT electrode placement on outcomes in TRP. We hypothesized that ECT would lead to greater reduction in positive symptoms, particularly in patients receiving clozapine.

METHODS

Retrospective study in a tertiary TRP program. The Positive and Negative Syndrome Scale (PANSS) was used for clinical outcomes, with positive subscore as primary outcome. Clinical and ECT data were analyzed using a linear modelling approach, controlling for relevant covariates.

RESULTS

A total of 309 patients were included. ECT plus clozapine associated with greater improvement in positive, general, and total symptoms than ECT alone. ECT associated with greater improvement in negative symptoms in depressed patients. Bifrontal placement was mostly equivalent to bitemporal, with greater reduction of positive symptoms in patients receiving clozapine, and associated with lower electrical dose in patients on anticonvulsants. Clozapine increased seizure duration, while anticonvulsants decreased it. Anticonvulsant use in ECT patients associated with equivalent to slightly improved symptom reduction.

CONCLUSIONS

ECT's benefit in TRP may be greatest in patients receiving clozapine. ECT can improve negative symptoms in depressed TRP patients. Bifrontal placement is effective in TRP. Clozapine and anticonvulsants have opposite effects on seizure duration, but anticonvulsants may not adversely affect clinical outcomes of ECT for TRP.

Mirtazapine in schizophrenia - an undeservedly overlooked option?

Mirtazapine has often been prescribed as add-on treatment for schizophrenia in patients with suboptimal response to conventional treatments. In this review, we evaluate the existing evidence for efficacy and effectiveness of add-on mirtazapine in schizophrenia and reappraise the practical and theoretical aspects of mirtazapine-antipsychotic combinations. In randomized controlled trials (RCTs), mirtazapine demonstrated favourable effects on negative and cognitive (although plausibly not depressive) symptoms, with no risk of psychotic exacerbation. Mirtazapine also may have a desirable effect on antipsychotic-induced sexual dysfunction, but seems not to alleviate extrapyramidal symptoms, at least if combined with second-generation antipsychotics. It is noteworthy that all published RCTs have been underpowered and relatively short in duration. In the only large pragmatic effectiveness study that provided analyses by add-on antidepressant, only mirtazapine was associated with both decreased rate of hospital admissions and number of in-patient days. Mirtazapine hardly affects the pharmacokinetics of antipsychotics. However, possible pharmacodynamic interactions (sedation and metabolic offence) should be borne in mind. The observed desired clinical effects of mirtazapine may be due to its specific receptor-blocking properties. Alternative theoretical explanations include its possible neuroprotective effect. Further well-designed RCTs and real-world effectiveness studies are needed to determine whether add-on mirtazapine should be recommended for difficult-to-treat schizophrenia.

Prescribing patterns of long-acting injectable antipsychotics in a community setting in South Africa

Background

Long-acting injectable antipsychotics (LAI - APs) improve adherence to antipsychotics and decrease functional decline in schizophrenia. Yet they are prescribed late, in patients with established functional decline. Although LAI - APs are widely prescribed in South Africa, there is a paucity of research regarding the prescription profile for LAI - APs.

Aim

This study aimed to describe prescribing practices for LAI - APs at psychiatric clinics.

Setting

Community psychiatric clinics in South Africa.

Methods

A retrospective review of the psychiatric files of all patients on LAI - APs attending the clinics over the study period was conducted. Sociodemographic, clinical and pharmacological information regarding the LAI - AP prescribed was extracted from the files.

Results

A total of 206 charts were examined. The mean age of the study population was 46 (SD ± 12) years. Significantly more patients were male (n = 154; 74.8%), single (n = 184, 89.3%) and unemployed (n = 115; 55.8%) (p < 0.001). Approximately half had a comorbid substance use disorder (47.6%). The most common indication for the prescription of a LAI - AP was non-adherence (66%). Only 9.7% of the patients were prescribed a LAI - AP alone. No significant socio-demographic or clinical characteristic was associated with this prescribing habit. A LAI - AP was prescribed in combination with an oral antipsychotic, mood stabiliser or antidepressant in 53.9%, 44.7% and 7.8% of patients, respectively.

Conclusion

Long-acting injectable antipsychotics were prescribed mainly following noncompliance with oral antipsychotics and may represent a missed opportunity to prevent functional decline. The high prevalence of LAI - AP polypharmacy has been highlighted.

Machine Learning Algorithm-Based Prediction Model for the Augmented Use of Clozapine with Electroconvulsive Therapy in Patients with Schizophrenia

The augmentation of clozapine with electroconvulsive therapy (ECT) has been an optimal treatment option for patients with treatment- or clozapine-resistant schizophrenia. Using data from the Research on Asian Psychotropic Prescription Patterns for Antipsychotics survey, which was the largest international psychiatry research collaboration in Asia, our study aimed to develop a machine learning algorithm-based substantial prediction model for the augmented use of clozapine with ECT in patients with schizophrenia in terms of precision medicine. A random forest model and least absolute shrinkage and selection operator (LASSO) model were used to develop a substantial prediction model for the augmented use of clozapine with ECT. Among the 3744 Asian patients with schizophrenia, those treated with a combination of clozapine and ECT were characterized by significantly greater proportions of females and inpatients, a longer duration of illness, and a greater prevalence of negative symptoms and social or occupational dysfunction than those not treated. In the random forest model, the area under the curve (AUC), which was the most preferred indicator of the prediction model, was 0.774. The overall accuracy was 0.817 (95% confidence interval, 0.793−0.839). Inpatient status was the most important variable in the substantial prediction model, followed by BMI, age, social or occupational dysfunction, persistent symptoms, illness duration > 20 years, and others. Furthermore, the AUC and overall accuracy of the LASSO model were 0.831 and 0.644 (95% CI, 0.615−0.672), respectively. Despite the subtle differences in both AUC and overall accuracy of the random forest model and LASSO model, the important variables were commonly shared by the two models. Using the machine learning algorithm, our findings allow the development of a substantial prediction model for the augmented use of clozapine with ECT in Asian patients with schizophrenia. This substantial prediction model can support further studies to develop a substantial prediction model for the augmented use of clozapine with ECT in patients with schizophrenia in a strict epidemiological context.

Predictors of functioning and clinical outcomes in inpatient with schizophrenia on clozapine augmented with antipsychotics

OBJECTIVE

We aimed at exploring predictors of improvement in clinical and functional outcomes of patients on clozapine with chronic treatment-resistant schizophrenia admitted into rehabilitation wards.

METHOD

In a cross-sectional study of 62 patients on clozapine augmented with oral and parenteral antipsychotics, predictors of HoNOS (Health of the Nation Outcome Scales) scores were analysed using ordinal logistic regression.

RESULT

Augmentation with parenteral antipsychotics was associated with lower psychotic symptom scores (OR 0.38 [95%CI 0.15, 0.99]) and activity of daily living scores (OR 0.36 [95%CI, 0.13, 0.96]) compared with oral antipsychotics. Increased age was a predictor of behavioural disturbances, physical illness and cognitive problems for all clozapine patients, and female gender was associated with the increase in depression scores.

CONCLUSION

The addition of parental antipsychotics to clozapine in patients with treatment-resistant schizophrenia might have potential benefits for clinical and functional outcomes and needs a further investigation.

Clozapine resistant schizophrenia: Newer avenues of management

About 40%-70% of the patients with treatment-resistant schizophrenia have a poor response to adequate treatment with clozapine. The impact of clozapine-resistant schizophrenia (CRS) is even greater than that of treatment resistance in terms of severe and persistent symptoms, relapses and hospitalizations, poorer quality of life, and healthcare costs. Such serious consequences often compel clinicians to try different augmentation strategies to enhance the inadequate clozapine response in CRS. Unfortunately, a large body of evidence has shown that antipsychotics, antidepressants, mood stabilizers, electroconvulsive therapy, and cognitive-behavioural therapy are mostly ineffective in augmenting clozapine response. When beneficial effects of augmentation have been found, they are usually small and of doubtful clinical significance or based on low-quality evidence. Therefore, newer treatment approaches that go beyond the evidence are needed. The options proposed include developing a clinical consensus about the augmentation strategies that are most likely to be effective and using them sequentially in patients with CRS. Secondly, newer approaches such as augmentation with long-acting antipsychotic injections or multi-component psychosocial interventions could be considered. Lastly, perhaps the most effective way to deal with CRS would be to optimize clozapine treatment, which might prevent clozapine resistance from developing. Personalized dosing, adequate treatment durations, management of side effects and non-adherence, collaboration with patients and caregivers, and addressing clinician barriers to clozapine use are the principal ways of ensuring optimal clozapine treatment. At present, these three options could the best way to manage CRS until research provides more firm directions about the effective options for augmenting clozapine response.

Antipsychotic Polypharmacy for the Management of Schizophrenia: Evidence and Recommendations

Schizophrenia is a debilitating illness with a lifetime prevalence estimate of 0.6% and consists of symptoms from the positive, negative, and cognitive domains. Social support, therapy, psychoeducation, and overall case management are very important aspects of the treatment of schizophrenia. However, as abnormalities in neurotransmission are one of the key findings of schizophrenia pathology, pharmacotherapies are cornerstones of the management of schizophrenia. Antipsychotics have been used as the primary pharmacological treatment of schizophrenia. These agents often have a good effect on reducing positive symptoms, but may not markedly improve negative symptoms or cognitive defects. However, at least 20% of individuals with schizophrenia do not experience a substantial response from monotherapy with antipsychotics. Further, despite evolving treatment protocols and advances in early recognition of the disorder, 70% of patients with schizophrenia require long-term, even lifetime, medication to control their symptoms and do not achieve complete recovery. To address these shortcomings, clinicians and research scientists have explored different combinations of treatments, polypharmacy, to improve the treatment of patients. Antipsychotic polypharmacy has been shown to cause more side effects than monotherapy, which is the main reason why most treatment guidelines caution against it. Antipsychotic monotherapy should be strived for and clozapine should be tried at the latest if two monotherapy trials with other antipsychotics have failed and no absolute contraindications exist. If residual symptoms exist despite trials of adequate dose and duration, other reasons that may reduce treatment effect should be ruled out. Long-acting injectables or blood concentration measurements should be considered to affirm compliance and proper serum levels. Antipsychotic polypharmacy should be considered and discussed with patients from whom the aforementioned procedures do not produce a satisfactory treatment result. In some cases, antipsychotic polypharmacy may produce better results than other forms of treatment augmentation, such as benzodiazepines. In particular, combining aripiprazole with clozapine may be effective in reducing treatment side effects or residual symptoms, and this is likely to hold true for combining other partial dopamine D₂ agonists with clozapine as well, although currently scant data exist. More research is needed, both in controlled but also real-world settings, to define optimal antipsychotic polypharmacy and/or other psychotropic treatment augmentation strategies for specific patient groups and situations.

Sarcosine as an add-on treatment to antipsychotic medication for people with schizophrenia: a systematic review and meta-analysis of randomized controlled trials

Background: N-methyl-glycine (sarcosine) may improve symptoms of schizophrenia via NMDA-receptor modulation. We undertook a systematic review and meta-analysis to determine the short- and long-term effectiveness of sarcosine for schizophrenia.Research design and methods: The databases Medline, Scopus, EMBASE, Cochrane Library, and PsycINFO were searched. We included six independent randomized controlled trials of sarcosine as add-on treatment to current antipsychotic medication, involving 234 adult participants with schizophrenia, and reporting data on symptom severity. Standardized mean differences (SMDs) were used to assess continuous outcomes.Results: In all of the trials, sarcosine was administered orally at 2 g/day. Treatment with sarcosine did not show a significant effect size at any of the pre-established time points (2, 4, 6, or >6 weeks), due to marked quantitative heterogeneity. However, sarcosine was associated with significant reductions of symptom severity in the subgroups of people with chronic schizophrenia and no treatment resistance (namely, without added-on clozapine) in relation to the SMD after 6 weeks treatment at -0.36 and -0.31, respectively.Conclusions: People with chronic and non-refractory schizophrenia may benefit from the use of sarcosine as an add-on treatment to antipsychotic medication. Due to the good tolerability of this compound, future trials with larger sample sizes appear worthwhile.

Augmentation of clozapine with ECT: a retrospective case analysis

OBJECTIVE

We sought to assess the effectiveness of clozapine augmentation with Electroconvulsive therapy (ECT) (C+ECT) in patients with clozapine-resistant schizophrenia.

METHODS

We conducted a retrospective review of electronic health records to identify patients treated with C+ECT. We determined the response to C+ECT and the rate of rehospitalisation over the year following treatment with C+ECT.

RESULTS

Forty-two patients were treated with C+ECT over a 10-year period. The mean age of the patients at initiation of ECT was 46.3 (SD = 8.2) years (range 27-62 years). The mean number of ECTs given was 10.6 (SD = 5.3) (range 3-25) with the majority receiving twice weekly ECT. Seventy-six per cent of patients (n = 32) showed a Clinical Global Impression-Improvement (CGI-I) score of ≤3 (at least minimally improved) following C+ECT. The mean number of ECT treatments was 10.6 (SD = 5.3) (range 3-25) with the majority receiving twice weekly ECT. Sixty-four per cent of patients experienced no adverse events. Response to C+ECT was not associated with gender, age, duration of illness or duration of clozapine treatment. Seventy-five per cent of responders remained out of hospital over the course of 1-year follow-up, while 70% of those with no response to C+ECT were not admitted to hospital. Three patients received maintenance ECT, one of whom was rehospitalised.

CONCLUSION

This study lends support to emerging evidence for the effectiveness of C+ECT in clozapine-resistant schizophrenia. These results are consistent with the results of a meta-analysis and the only randomised controlled trial (RCT) of this intervention. Further RCTs are required before this treatment can be confidently recommended.

[The effect of various forms of folates on cognitive functions in patients with chronic schizophrenia]

OBJECTIVE

To assess the dynamics of cognitive functions in patients with schizophrenia during intake of various forms of folate as an add-on to antipsychotic therapy.

MATERIAL AND METHODS

Using a battery of cognitive tests, the authors evaluated the dynamics of cognitive functions in 3 groups of patients with schizophrenia who received folic acid (n=25), metafolin (n=25) during 4 weeks and in the control group (n=25). Genetic variants of the polymorphism of the folate metabolism enzyme methylenetetrahydrofolate reductase (MTHFR) 677C>T were determined using real-time PCR. Only the carriers of the minor T allele were included in the study.

RESULTS AND CONCLUSION

The improvement of certain cognitive functions was noted after folate administration, it was more pronounced and statistically significant in the metapholin group. The results hold promises for further studies of prolonged use of folate in prophylactic doses for schizophrenia.

A Review of Multimodal Hallucinations: Categorization, Assessment, Theoretical Perspectives, and Clinical Recommendations

Hallucinations can occur in different sensory modalities, both simultaneously and serially in time. They have typically been studied in clinical populations as phenomena occurring in a single sensory modality. Hallucinatory experiences occurring in multiple sensory systems-multimodal hallucinations (MMHs)-are more prevalent than previously thought and may have greater adverse impact than unimodal ones, but they remain relatively underresearched. Here, we review and discuss: (1) the definition and categorization of both serial and simultaneous MMHs, (2) available assessment tools and how they can be improved, and (3) the explanatory power that current hallucination theories have for MMHs. Overall, we suggest that current models need to be updated or developed to account for MMHs and to inform research into the underlying processes of such hallucinatory phenomena. We make recommendations for future research and for clinical practice, including the need for service user involvement and for better assessment tools that can reliably measure MMHs and distinguish them from other related phenomena.

Cognitive-behavioural therapy for clozapine-resistant schizophrenia: the FOCUS RCT

BACKGROUND

Clozapine (clozaril, Mylan Products Ltd) is a first-choice treatment for people with schizophrenia who have a poor response to standard antipsychotic medication. However, a significant number of patients who trial clozapine have an inadequate response and experience persistent symptoms, called clozapine-resistant schizophrenia (CRS). There is little evidence regarding the clinical effectiveness of pharmacological or psychological interventions for this population.

OBJECTIVES

To evaluate the clinical effectiveness and cost-effectiveness of cognitive-behavioural therapy (CBT) for people with CRS and to identify factors predicting outcome.

DESIGN

The Focusing on Clozapine Unresponsive Symptoms (FOCUS) trial was a parallel-group, randomised, outcome-blinded evaluation trial. Randomisation was undertaken using permuted blocks of random size via a web-based platform. Data were analysed on an intention-to-treat (ITT) basis, using random-effects regression adjusted for site, age, sex and baseline symptoms. Cost-effectiveness analyses were carried out to determine whether or not CBT was associated with a greater number of quality-adjusted life-years (QALYs) and higher costs than treatment as usual (TAU).

SETTING

Secondary care mental health services in five cities in the UK.

PARTICIPANTS

People with CRS aged ≥ 16 years, with an International Classification of Diseases, Tenth Revision (ICD-10) schizophrenia spectrum diagnoses and who are experiencing psychotic symptoms.

INTERVENTIONS

Individual CBT included up to 30 hours of therapy delivered over 9 months. The comparator was TAU, which included care co-ordination from secondary care mental health services.

MAIN OUTCOME MEASURES

The primary outcome was the Positive and Negative Syndrome Scale (PANSS) total score at 21 months and the primary secondary outcome was PANSS total score at the end of treatment (9 months post randomisation). The health benefit measure for the economic evaluation was the QALY, estimated from the EuroQol-5 Dimensions, five-level version (EQ-5D-5L), health status measure. Service use was measured to estimate costs.

RESULTS

Participants were allocated to CBT (n = 242) or TAU (n = 245). There was no significant difference between groups on the prespecified primary outcome [PANSS total score at 21 months was 0.89 points lower in the CBT arm than in the TAU arm, 95% confidence interval (CI) -3.32 to 1.55 points; p = 0.475], although PANSS total score at the end of treatment (9 months) was significantly lower in the CBT arm (-2.40 points, 95% CI -4.79 to -0.02 points; p = 0.049). CBT was associated with a net cost of £5378 (95% CI -£13,010 to £23,766) and a net QALY gain of 0.052 (95% CI 0.003 to 0.103 QALYs) compared with TAU. The cost-effectiveness acceptability analysis indicated a low likelihood that CBT was cost-effective, in the primary and sensitivity analyses (probability < 50%). In the CBT arm, 107 participants reported at least one adverse event (AE), whereas 104 participants in the TAU arm reported at least one AE (odds ratio 1.09, 95% CI 0.81 to 1.46; p = 0.58).

CONCLUSIONS

Cognitive-behavioural therapy for CRS was not superior to TAU on the primary outcome of total PANSS symptoms at 21 months, but was superior on total PANSS symptoms at 9 months (end of treatment). CBT was not found to be cost-effective in comparison with TAU. There was no suggestion that the addition of CBT to TAU caused adverse effects. Future work could investigate whether or not specific therapeutic techniques of CBT have value for some CRS individuals, how to identify those who may benefit and how to ensure that effects on symptoms can be sustained.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN99672552.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 23, No. 7. See the NIHR Journals Library website for further project information.

Cannabidiol as a treatment option for schizophrenia: recent evidence and current studies

PURPOSE OF REVIEW

The most recent studies published or initiated in the last 18 months, investigating cannabidiol in the treatment of symptoms of schizophrenia and related conditions are summarized, including observed tolerability and reported side-effects.

RECENT FINDINGS

Recent studies focused on patients with sub-acute psychotic syndromes of schizophrenia, clinical high-risk state for psychosis (CHR-P), or frequent cannabis users, as well as cognitive functioning in chronic schizophrenia. There is further, although not consistent evidence for cannabidiol-reducing positive symptoms, but not negative symptoms. Evidence for improvement of cognition was weaker, with one study reporting a worsening. Regarding side effects and tolerability, cannabidiol induced sedation in one study, with the other studies indicating good tolerability, even at high doses.

SUMMARY

Recent clinical trials added further evidence for an antipsychotic potential of cannabidiol. In general, studies following trial designs as suggested by regulators in schizophrenia are needed in sufficient numbers to clarify the safety and efficacy of cannabidiol herein. In addition, such studies will further elucidate its ability to target specific aspects of the syndrome, such as negative or cognitive symptoms. Furthermore, aiming for an add-on treatment with cannabidiol will require further studies to identify potentially useful or even harmful combinations.

Perceptions of Psychiatrists Toward the Use of Long-Acting Injectable Antipsychotics: An Online Survey Study From India

PURPOSE/BACKGROUND

Despite proven benefits of long-acting injectables (LAIs), these are frequently underused by the psychiatrists. Accordingly, this study aimed to explore the perceptions of psychiatrists toward the use of LAI antipsychotics in their routine clinical practice.

METHODS/PROCEDURE

An online e-mail survey was conducted by using Survey Monkey platform.

RESULTS

A total of 622 psychiatrists with a mean age of 41 years who were in psychiatric practice for approximately 14 years participated in the survey. Participants reported using LAI, mainly for patients with schizophrenia, with LAI prescribed to approximately one-tenth (9.30%) of their patients in acute phase of illness and in one-fifth (18.42%) of patients in stabilization/stable phase. Fluphenazine decanoate (32.7%) was the most commonly used LAI followed by flupenthixol decanoate (19.5%), haloperidol decanoate (17.8%), and olanzapine pamoate (11.1%). The most common reasons for starting LAI were history of medication (100%) and treatment (80.5%) nonadherence, followed by having frequent relapses/exacerbations of symptoms (54.8%). Overall, more than half of the participants felt the level of acceptance of LAI among patients offered to be quite reasonable (54.3%), and mostly, LAIs were used as combination therapy with oral antipsychotics (73.6%). Despite all these, approximately three-fifths (59%) of the participants reported that they underuse LAI to a certain extent, with most common reasons that deter them from using LAI being the cost (55.45%), lack of interest of patients in receiving LAI (42.9%), lack of regular availability (41.3%), and patients being scared of receiving injectables (41.2%).

CONCLUSIONS/IMPLICATIONS

The LAI antipsychotics despite having several benefits are still underused by a substantial proportion of practicing psychiatrists.

Polypharmacy in schizophrenia

Schizophrenia is a severe mental disorder characterized by a heterogeneous symptom profile which comprises a clinical platform for widespread use of polypharmacy even though antipsychotic monotherapy is the recommended treatment regimen. This narrative review provides a summary of the current gap between evidence and practice for use of antipsychotic combination therapy in patients with schizophrenia. Antipsychotic polypharmacy is frequently prescribed instead of following international consensus of clozapine monotherapy in treatment-resistant patients. Antipsychotic-benzodiazepine combination therapy clearly has a role in the treatment of acute agitation whereas there is no evidence to support an effect on core schizophrenia symptoms when chronically prescribed. Antidepressants are typically added to antipsychotic treatment in case of persistent negative symptoms. Available evidence suggests that antidepressants may improve negative symptom control in schizophrenia. Combining an antipsychotic with an antiepileptic is not supported by any firm evidence, but individual mood stabilizers have come out positively in single trials. Generally, the evidence base for polypharmacy in schizophrenia maintenance treatment is sparse but may be warranted in certain clinical situations. Therapeutic benefits and side effects should be carefully monitored and considered to ensure a beneficial risk-benefit ratio if prescribing polypharmacy for specific clinical indications.

Evidence-based guidelines for the pharmacological treatment of schizophrenia: Updated recommendations from the British Association for Psychopharmacology

These updated guidelines from the British Association for Psychopharmacology replace the original version published in 2011. They address the scope and targets of pharmacological treatment for schizophrenia. A consensus meeting was held in 2017, involving experts in schizophrenia and its treatment. They were asked to review key areas and consider the strength of the evidence on the risk-benefit balance of pharmacological interventions and the clinical implications, with an emphasis on meta-analyses, systematic reviews and randomised controlled trials where available, plus updates on current clinical practice. The guidelines cover the pharmacological management and treatment of schizophrenia across the various stages of the illness, including first-episode, relapse prevention, and illness that has proved refractory to standard treatment. It is hoped that the practice recommendations presented will support clinical decision making for practitioners, serve as a source of information for patients and carers, and inform quality improvement.

The clozapine to norclozapine ratio: a narrative review of the clinical utility to minimize metabolic risk and enhance clozapine efficacy

Introduction: Clozapine remains the most effective antipsychotic for treatment-refractory schizophrenia. However, ~40% of the patients respond insufficiently to clozapine. Clozapine's effects, both beneficial and adverse, have been proposed to be partially attributable to its main metabolite, N-desmethylclozapine (NDMC). However, the relation of the clozapine to norclozapine ratio (CLZ:NDMC; optimally defined as ~2) to clinical response and metabolic outcomes is not clear.Areas covered: This narrative review comprehensively examines the clinical utility of the CLZ:NDMC ratio to reduce metabolic risk and increase treatment efficacy. The association of the CLZ:NDMC ratio with changes in psychopathology, cognitive functioning, and cardiometabolic burden will be explored, as well as adjunctive treatments and their effects.Expert opinion: The literature suggests a positive association between the CLZ:NDMC ratio and better cardiometabolic outcomes. Conversely, the CLZ:NDMC ratio appears inversely associated with better cognitive functioning but less consistently with other psychiatric domains. The CLZ:NDMC ratio may be useful for predicting and monitoring cardiometabolic adverse effects and optimizing potential cognitive benefits of clozapine. Future studies are required to replicate these findings, which if substantiated, would encourage examination of adjunctive treatments aiming to alter the CLZ:NDMC ratio to best meet the needs of the individual patient, thereby broadening clozapine's clinical utility.

Clozapine augmentation strategies

Clozapine is established as the gold standard for antipsychotic treatment of patients suffering from treatment-resistant schizophrenia. Over virtually 3 decades, the level of inadequate response to clozapine was found to range from 40% to 60%. A heightened interest developed in the augmentation of clozapine to try to achieve response or maximize partial response. A large variety of drug groups have been investigated. This article focuses on the meta-analyses of these trials to discover reasonable evidence-based approaches to the management of patients not responding to clozapine.

Treatment resistant schizophrenia: Clinical, biological, and therapeutic perspectives

Treatment resistant schizophrenia (TRS) refers to the significant proportion of schizophrenia patients who continue to have symptoms and poor outcomes despite treatment. While many definitions of TRS include failure of two different antipsychotics as a minimum criterion, the wide variability in inclusion criteria has challenged the consistency and reproducibility of results from studies of TRS. We begin by reviewing the clinical, neuroimaging, and neurobiological characteristics of TRS. We further review the current treatment strategies available, addressing clozapine, the first-line pharmacological agent for TRS, as well as pharmacological and non-pharmacological augmentation of clozapine including medication combinations, electroconvulsive therapy, repetitive transcranial magnetic stimulation, deep brain stimulation, and psychotherapies. We conclude by highlighting the most recent consensus for defining TRS proposed by the Treatment Response and Resistance in Psychosis Working Group, and provide our overview of future perspectives and directions that could help advance the field of TRS research, including the concept of TRS as a potential subtype of schizophrenia.

Systematic review and exploratory meta-analysis of the efficacy, safety, and biological effects of psychostimulants and atomoxetine in patients with schizophrenia or schizoaffective disorder

OBJECTIVE

Our aim was to summarize the efficacy and safety of atomoxetine, amphetamines, and methylphenidate in schizophrenia.

METHODS

We undertook a systematic review, searching PubMed/Scopus/Clinicaltrials.gov for double-blind, randomized, placebo-controlled studies of psychostimulants or atomoxetine in schizophrenia published up to 1 January 2017. A meta-analysis of outcomes reported in two or more studies is presented.

RESULTS

We included 22 studies investigating therapeutic effects of stimulants (k=14) or measuring symptomatic worsening/relapse prediction after stimulant challenge (k=6). Six studies of these two groups plus one additional study investigated biological effects of psychostimulants or atomoxetine. No effect resulted from interventional studies on weight loss (k=1), smoking cessation (k=1), and positive symptoms (k=12), and no improvement was reported with atomoxetine (k=3) for negative symptoms, with equivocal findings for negative (k=6) and mood symptoms (k=2) with amphetamines. Attention, processing speed, working memory, problem solving, and executive functions, among others, showed from no to some improvement with atomoxetine (k=3) or amphetamines (k=6). Meta-analysis did not confirm any effect of stimulants in any symptom domain, including negative symptoms, apart from atomoxetine improving problem solving (k=2, standardized mean difference (SMD)=0.73, 95% CI=0.10-1.36, p=0.02, I2=0%), and trending toward significant improvement in executive functions with amphetamines (k=2, SMD=0.80, 95% CI=-1.68 to +0.08, p=0.08, I2=66%). In challenge studies, amphetamines (k=1) did not worsen symptoms, and methylphenidate (k=5) consistently worsened or predicted relapse. Biological effects of atomoxetine (k=1) and amphetamines (k=1) were cortical activation, without change in β-endorphin (k=1), improved response to antipsychotics after amphetamine challenge (k=2), and an increase of growth hormone-mediated psychosis with methylphenidate (k=2). No major side effects were reported (k=6).

CONCLUSIONS

No efficacy for stimulants or atomoxetine on negative symptoms is proven. Atomoxetine or amphetamines may improve cognitive symptoms, while methylphenidate should be avoided in patients with schizophrenia. Insufficient evidence is available to draw firm conclusions.

Clinical Course, Neurobiology and Therapeutic Approaches to Treatment Resistant Schizophrenia. Toward an Integrated View

Despite considerable psychotherapeutic advancement since the discovery of chlorpromazine, almost one third of patients with schizophrenia remain resistant to dopamine-blocking antipsychotics, and continue to be exposed to unwanted and often disabling side effects, but little if any clinical benefit. Even clozapine, the superior antipsychotic treatment, is ineffective in approximately half of these patients. Thus treatment resistant schizophrenia (TRS), continues to present a major therapeutic challenge to psychiatry. The main impediment to finding novel treatments is the lack of understanding of precise molecular mechanisms leading to TRS. Not only has the neurobiology been enigmatic for decades, but accurate and early detection of patients who are at risk of not responding to dopaminergic blockade remains elusive. Fortunately, recent work has started to unravel some of the neurobiological mechanisms underlying treatment resistance, providing long awaited answers, at least to some extent. Here we focus on the scientific advances in the field, from the clinical course of TRS to neurobiology and available treatment options. We specifically emphasize emerging evidence from TRS imaging and genetic literature that implicates dysregulation in several neurotransmitters, particularly dopamine and glutamate, and in addition genetic and neural alterations that concertedly may lead to the formation of TRS. Finally, we integrate available findings into a putative model of TRS, which may provide a platform for future studies in a bid to open the avenues for subsequent development of effective therapeutics.

Young patient with treatment-resistant schizophrenia drastically improved by combination of clozapine and maintenance electroconvulsive therapy: a case report

Objectives: Although clozapine is considered the only effective pharmacological option for patients with treatment-resistant schizophrenia (TRS), around 30–40% of patients show clozapine resistance. Modified electroconvulsive therapy augmentation is reportedly clinically effective for clozapine-resistant schizophrenia, but few case reports have described the efficacy of combining clozapine and continuous/maintenance ECT for patients with TRS.

Methods: We present the case of a young patient with TRS who was treated using combination therapy with clozapine and maintenance ECT (m-ECT).

Results: The patient achieved drastic improvement under combination therapy with clozapine and m-ECT. Total Positive and Negative Syndrome Scale (PANSS) score fell markedly by 36 (from 108 to 72) using the combination of clozapine and m-ECT. Behaviors not reflected directly by PANSS score also improved. For example, the problem of being unable to take oral drugs stably because of delusions of poisoning was resolved. Furthermore, the patient maintained improvement under m-ECT, and long-term homestays became possible.

Conclusion: Combination therapy with clozapine and m-ECT proved greatly effective in this case. Further clinical trials of this combination therapy for TRS are needed to confirm the effectiveness. Further studies are also expected to examine effective periods for this therapy.

Association of Antipsychotic Polypharmacy vs Monotherapy With Psychiatric Rehospitalization Among Adults With Schizophrenia

IMPORTANCE

The effectiveness of antipsychotic polypharmacy in schizophrenia relapse prevention is controversial, and use of multiple agents is generally believed to impair physical well-being.

OBJECTIVE

To study the association of specific antipsychotic combinations with psychiatric rehospitalization.

DESIGN, SETTING, AND PARTICIPANTS

In this nationwide cohort study, the risk of psychiatric rehospitalization was used as a marker for relapse among 62 250 patients with schizophrenia during the use of 29 different antipsychotic monotherapy and polypharmacy types between January 1, 1996, and December 31, 2015, in a comprehensive, nationwide cohort in Finland. We conducted analysis of the data from April 24 to June 15, 2018. Rehospitalization risks were investigated by using within-individual analyses to minimize selection bias.

MAIN OUTCOMES AND MEASURES

Hazard ratio (HR) for psychiatric rehospitalization during use of polypharmacy vs during monotherapy within the same individual.

RESULTS

In the total cohort, including 62 250 patients, 31 257 individuals (50.2%) were men, and the median age was 45.6 (interquartile range, 34.6-57.9) years. The clozapine plus aripiprazole combination was associated with the lowest risk of psychiatric rehospitalization in the total cohort, being superior to clozapine, the monotherapy associated with the best outcomes, with a difference of 14% (HR, 0.86; 95% CI, 0.79-0.94) in the analysis including all polypharmacy periods, and 18% in the conservatively defined polypharmacy analysis excluding periods shorter than 90 days (HR, 0.82; 95% CI, 0.75-0.89; P < .001). Among patients with their first episode of schizophrenia, these differences between clozapine plus aripiprazole vs clozapine monotherapy were greater (difference, 22%; HR, 0.78; 95% CI, 0.63-0.96 in the analysis including all polypharmacy periods, and difference, 23%; HR, 0.77; 95% CI, 0.63-0.95 in the conservatively defined polypharmacy analysis). At the aggregate level, any antipsychotic polypharmacy was associated with a 7% to 13% lower risk of psychiatric rehospitalization compared with any monotherapy (ranging from HR, 0.87; 95% CI, 0.85-0.88, to HR, 0.93; 95% CI, 0.91-0.95; P < .001). Clozapine was the only monotherapy among the 10 best treatments. Results on all-cause and somatic hospitalization, mortality, and other sensitivity analyses were in line with the primary outcomes.

CONCLUSIONS AND RELEVANCE

Combining aripiprazole with clozapine was associated with the lowest risk of rehospitalization, indicating that certain types of polypharmacy may be feasible in the treatment of schizophrenia. Because add-on treatments are started when monotherapy is no longer sufficient to control for worsening of symptoms, it is likely that the effect sizes for polypharmacy are underestimates. Although the results do not indicate that all types of polypharmacy are beneficial, the current treatment guidelines should modify their categorical recommendations discouraging all antipsychotic polypharmacy in the maintenance treatment of schizophrenia.

Clozapine augmentation strategies - a systematic meta-review of available evidence. Treatment options for clozapine resistance

BACKGROUND

Treatment options for clozapine resistance are diverse whereas, in contrast, the evidence for augmentation or combination strategies is sparse.

AIMS

We aimed to extract levels of evidence from available data and extrapolate recommendations for clinical practice.

METHODS

We conducted a systematic literature search in the PubMed/MEDLINE database and in the Cochrane database. Included meta-analyses were assessed using Scottish Intercollegiate Guidelines Network criteria, with symptom improvement as the endpoint, in order to develop a recommendation grade for each clinical strategy identified.

RESULTS

Our search identified 21 meta-analyses of clozapine combination or augmentation strategies. No strategies met Grade A criteria. Strategies meeting Grade B included combinations with first- or second-generation antipsychotics, augmentation with electroconvulsive therapy for persistent positive symptoms, and combination with certain antidepressants (fluoxetine, duloxetine, citalopram) for persistent negative symptoms. Augmentation strategies with mood-stabilisers, anticonvulsants, glutamatergics, repetitive transcranial magnetic stimulation, transcranial direct current stimulation or cognitive behavioural therapy met Grades C-D criteria only.

CONCLUSION

More high-quality clinical trials are needed to evaluate the efficacy of add-on treatments for symptom improvement in patients with clozapine resistance. Applying definitions of clozapine resistance would improve the reporting of future clinical trials. Augmentation with second-generation antipsychotics and first-generation antipsychotics can be beneficial, but the supporting evidence is from low-quality studies. Electroconvulsive therapy may be effective for clozapine-resistant positive symptoms.

Dandy-Walker Malformation-Like Condition Revealed by Refractory Schizophrenia: A Case Report and Literature Review

INTRODUCTION

Dandy-Walker malformation is a rare congenital malformation involving cystic dilatation of the fourth ventricle, enlarged posterior fossa, complete or partial agenesis of the cerebellar vermis, elevated tentorium cerebelli, and hydrocephalus. Previous research highlighted a possible role for the cerebellum in schizophrenia as well as the contribution of underlying brain malformations to treatment resistance. Here, we present a case of a Dandy-Walker malformation-like condition revealed by a refractory schizophrenia in a 24-year-old male patient. We also conduct a literature review of all previously published case reports or case series of co-occurring posterior fossa abnormalities and schizophrenia or psychosis using a PubMed search query to better understand the potential link between these two disorders.

CASE PRESENTATION

A 9-month hospital stay was needed to address the treatment-resistant psychotic symptoms, and the patient continued to experience moderate symptoms despite the prescription of various antipsychotic and antidepressant medications. After an irregular initial medical follow-up, the patient is currently treated with 350 mg daily clozapine and 20 mg daily prazepam and still exhibits moderate anxiety without delirious thoughts, however allowing him to re-enroll at the university. Regarding the literature, 24 cases published between 1996 and 2017 were identified, reviewed and compared to the present case report.

DISCUSSION

This case report and literature review further illuminates the pathophysiology of psychotic disorders including the potential role of the cerebellum, reinforces the importance of a multidisciplinary approach for the neurological and psychiatric management of patients with schizophrenia, and highlights optimal pharmacological management strategies for treatment-resistant schizophrenia.

Topiramate mitigates weight gain in antipsychotic-treated patients with schizophrenia: meta-analysis of randomised controlled trials

OBJECTIVE

Weight gain is one of the most challenging issues in patients with schizophrenia treated with antipsychotics. Several meta-analyses have been conducted to review the efficacy of topiramate in reducing weight, however, several issues regarding the methodology had arisen of which make the results remain ambiguous.

METHODS

We conducted a meta-analysis of randomised controlled trials about the use of topiramate in patients with schizophrenia for weight reduction. Ten double-blinded randomised placebo-controlled trials and seven open-label randomised controlled trials included 905 patients.

RESULTS

Patients treated with topiramate experienced a greater reduction in body weight and BMI. Patients in countries of the lower overweight population showed more significant BMI reduction. Besides, studies from the Middle East and South Asia showed the greatest effect in body weight change, followed by East Asia, then Europe/America. Topiramate group was outperformed control group with significant psychopathology improvement. No difference between two groups regarding the overall side effects.

CONCLUSIONS

Topiramate was significantly superior to control group in mitigating weight gain and psychopathology in antipsychotic-treated patients with schizophrenia. The effects of topiramate augmentation need further investigations in larger definitive studies using methodological rigor and thorough assessments.

Maximizing response to first-line antipsychotics in schizophrenia: a review focused on finding from meta-analysis

RATIONALE

There are many psychotropic drugs available for treatment of schizophrenia. The clinician's choice of the most effective first-line antipsychotic treatment for patients with schizophrenia should balance considerations of differential efficacy of antipsychotics against the relative risk of different side effects.

METHOD

We reviewed recent studies using meta-analytic techniques and additional studies of new antipsychotics which quantitatively evaluate the efficacy of side effects of first- and second-generation antipsychotics and studies of the efficacy on add-on secondary medications. We present an integrated summary of these results to guide a clinician's decision-making.

RESULTS

Recent meta-analyses have suggested that antipsychotics are not equivalent in efficacy. Clozapine (effect size [SMD] 0.88 vs. placebo), amisulpride (effect size 0.6 vs placebo), olanzapine (effect size 0.59 vs. placebo), and risperidone (effect size 0.56 vs placebo) show small but statistically significant differences compared to a number of other antipsychotics on measures of overall efficacy (effect sizes 0.33-0.50). However, increasing placebo response remains a concern in interpreting these data. Amisulpride (effect size 0.47 vs placebo) and cariprazine (effect size in one trial compared to risperidone 0.29) have the strongest evidence indicating greater efficacy for treating primary negative symptoms relative to other antipsychotics. In terms of side effects, clozapine and olanzapine have among the highest weight gain potential and sertindole and amisulpride have more effects on QTc prolongation than other commonly used antipsychotics. Prolactin elevation is highest with paliperidone, risperidone, and amisulpride. Adjunctive treatment with an antidepressant drug may improve response in patients with schizophrenia who also have severe depressive or negative symptoms. For multi-episode patients with an inadequate response to an adequate dose and duration of the initial antipsychotic choice, switching to another antipsychotic, with a different receptor profile, may improve response, although evidence is very limited. In first-episode patients, a recent study on switching to another antipsychotic, with a different receptor profile after 4 weeks demonstrated no beneficial effects. There is little evidence to support using doses above the therapeutic range other than in exceptional circumstances.

CONCLUSIONS

Our review of recent studies using meta-analytic techniques has provided evidence that all antipsychotics are not equal in the severity of different side effects and in some measures of clinical efficacy. Comparative analysis and rankings from network meta-analyses can provide guidance to clinicians in choosing the most appropriate antipsychotic for first-line treatment, if used in conjunction with available information of the patient's history of previous clinical response or higher risks for specific side effects.

Clinical Trials and Therapeutic Rationale for Drug Repurposing in Schizophrenia

There is a paucity of efficacious novel drugs to address high rates of treatment resistance and refractory symptoms in schizophrenia. The identification of novel therapeutic indications for approved drugs-drug repurposing-has the potential to expedite clinical trials and reduce the costly risk of failure which currently limits central nervous system drug discovery efforts. In the present Review we discuss the historical role of drug repurposing in schizophrenia drug discovery and review the main classes of repurposing candidates currently in clinical trials for schizophrenia in terms of their therapeutic rationale, mechanisms of action, and preliminary results from clinical trials. Subsequently we outline the challenges and limitations which face the clinical repurposing pipeline and how novel technologies might serve to address these.

Treatment resistant schizophrenia - review and a call to action

Recovery rates in schizophrenia remain suboptimal with up to one-third resistant to standard treatments, a population prevalence of 0.2%. Clozapine is the only evidenced-based treatment for treatment resistant schizophrenia (TRS), yet there are significant delays in its use or it may not be trialled, potentially impacting the chance of recovery. Better outcomes with earlier use of clozapine may be possible. There is emerging evidence that early treatment resistance is not uncommon from the earliest stages of psychosis. In this review, we provide an update on TRS, its epidemiology and its management, with a specific focus on the optimal use and timing of clozapine and augmentation strategies for the one-third of patients who do not respond to clozapine.

Resistance is not futile: treatment-refractory schizophrenia - overview, evaluation and treatment

INTRODUCTION

Schizophrenia is a debilitating condition with three main symptom domains: positive, negative, and cognitive. Approximately one-third of persons with schizophrenia will fail to respond to treatment. Growing evidence suggests that treatment-resistant (refractory) schizophrenia (TRS) may be a distinct condition from treatment-respondent schizophrenia. There is limited evidence on effective treatments for TRS, and a lack of standardized diagnostic criteria for TRS has hampered research. Areas covered: A literature search was conducted using Pubmed.gov and the EMBASE literature database. The authors discuss the pragmatic definitions of TRS and review treatments consisting of antipsychotic monotherapy and augmentation strategies. Expert opinion: Currently available first-line antipsychotic medications are generally effective at treating the positive symptoms of schizophrenia, leaving residual negative and cognitive symptoms. Before diagnosing TRS, rule out any pharmacodynamic or pharmacokinetic failures. Most evidence supports clozapine as having the most efficacy for TRS. If clozapine is used, it should be optimized, and serum levels should be at least 350-420 ng/ml. If clozapine is unable to be tolerated, some evidence suggests olanzapine at dosages up to 40mg/day can be useful. Augmentation strategies have weak evidence. Tailoring treatment to the specific domain is the preferred approach, and the use of a structured assessment/outcome measure is encouraged.

The acute efficacy of antipsychotics in schizophrenia: a review of recent meta-analyses

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 μg/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.

The impact of delay in clozapine initiation on treatment outcomes in patients with treatment-resistant schizophrenia: A systematic review

Approximately one-third of patients with schizophrenia have treatment-resistant schizophrenia (TR-SCZ), which is a condition characterized by suboptimal response to antipsychotics other than clozapine. Importantly, treatment with clozapine-the only antipsychotic with an indication for TR-SCZ-is often delayed, which could contribute to negative outcomes. Given that the specific impact of delay in clozapine initiation is not well understood, we aimed to conduct a systematic search of the Ovid Medline^® database to identify English language publications exploring the impact of delay in clozapine initiation on treatment outcomes in patients with TR-SCZ. Additionally, clinico-demographic factors associated with clozapine delay were examined. Our search identified four retrospective studies that showed an association between longer delay in clozapine initiation and poorer treatment outcomes, even after including covariates, such as age, sex, and duration of illness. In addition, we found six studies that showed an association between age and clozapine delay, but results with regard to other clinico-demographic variables were inconsistent. Overall, the available literature reveals a possible link between delay in clozapine use and poorer treatment outcomes in patients with TR-SCZ. However, given the relatively small number of studies on this clinically important topic, future research is warranted to draw more definitive conclusions.

ECT augmentation of clozapine for clozapine-resistant schizophrenia: A meta-analysis of randomized controlled trials

Treatment-resistant schizophrenia (TRS) is common and debilitating. A subgroup of patients even has clozapine-resistant schizophrenia (CRS). We aimed to evaluate the efficacy and safety of electroconvulsive therapy (ECT) augmentation of clozapine for CRS. Systematic literature search of randomized controlled trials (RCTs) reporting on ECT augmentation of clozapine in CRS. Co-primary outcomes included symptomatic improvement at post-ECT assessment and study endpoint. Eighteen RCTs (n = 1769) with 20 active treatment arms were identified and meta-analyzed. Adjunctive ECT was superior to clozapine regarding symptomatic improvement at post-ECT assessment (Standardized Mean Difference (SMD) = -0.88, 95% Confidence Interval (CI): -1.33 to -0.44; I² = 86%, P = 0.0001) and endpoint assessment (SMD: -1.44, 95%CI: -2.05 to -0.84; I² = 95%, P < 0.00001), separating as early as week 1-2 (SMD = -0.54, 95%CI: -0.88 to -0.20; I² = 77%, P = 0.002). Adjunctive ECT was also superior regarding study-defined response at post-ECT assessment (53.6% vs. 25.4%, Risk Ratio (RR) = 1.94, 95%CI: 1.59-2.36; I² = 0%, P < 0.00001, number-needed-to-treat (NNT) = 3, 95%CI: 3-5) and endpoint assessment (67.7% vs. 41.4%, RR = 1.66, 95%CI: 1.38-1.99; I² = 47%, P < 0.00001, NNT = 4, 95%CI: 3-8), and remission at post-ECT assessment (13.3% vs. 3.7%, RR = 3.28, 95%CI: 1.80-5.99; I² = 0%, P = 0.0001, NNT = 13, 95%CI: 6-100) and endpoint assessment (23.6% vs. 13.3%, RR = 1.80, 95%CI: 1.39 to 2.35; I² = 5%, P < 0.0001, NNT = 14, 95%CI: 6-50). Patient-reported memory impairment (24.2% vs. 0%; RR = 16.10 (95%CI: 4.53-57.26); I² = 0%, P < 0.0001, number-needed-to-harm (NNH) = 4, 95%CI: 2-14) and headache (14.5% vs 1.6%; RR = 4.03 (95%CI: 1.54-10.56); I² = 0%, P = 0.005, NNH = 8, 95%CI: 4-50) occurred more frequently with adjunctive ECT. No significant group differences were found regarding discontinuation and other adverse effects. Despite increased frequency of self-reported memory impairment and headache, ECT augmentation of clozapine is a highly effective and relatively safe treatment for CRS.

REGISTRATION NUMBER

CRD42018089959.

Sodium Benzoate, a D-Amino Acid Oxidase Inhibitor, Added to Clozapine for the Treatment of Schizophrenia: A Randomized, Double-Blind, Placebo-Controlled Trial

BACKGROUND

Clozapine is the last-line antipsychotic agent for refractory schizophrenia. To date, there is no convincing evidence for augmentation on clozapine. Activation of N-methyl-D-aspartate receptors, including inhibition of D-amino acid oxidase that may metabolize D-amino acids, has been reported to be beneficial for patients receiving antipsychotics other than clozapine. This study aimed to examine the efficacy and safety of a D-amino acid oxidase inhibitor, sodium benzoate, for schizophrenia patients who had poor response to clozapine.

METHODS

We conducted a randomized, double-blind, placebo-controlled trial. Sixty schizophrenia inpatients that had been stabilized with clozapine were allocated into three groups for 6 weeks' add-on treatment of 1 g/day sodium benzoate, 2 g/day sodium benzoate, or placebo. The primary outcome measures were Positive and Negative Syndrome Scale (PANSS) total score, Scale for the Assessment of Negative Symptoms, Quality of Life Scale, and Global Assessment of Functioning. Side effects and cognitive functions were also measured.

RESULTS

Both doses of sodium benzoate produced better improvement than placebo in the Scale for the Assessment of Negative Symptoms. The 2 g/day sodium benzoate also produced better improvement than placebo in PANSS-total score, PANSS-positive score, and Quality of Life Scale. Sodium benzoate was well tolerated without evident side effects. The changes of catalase, an antioxidant, were different among the three groups and correlated with the improvement of PANSS-total score and PANSS-positive score in the sodium benzoate group.

CONCLUSIONS

Sodium benzoate adjuvant therapy improved symptomatology of patients with clozapine-resistant schizophrenia. Further studies are warranted to elucidate the optimal dose and treatment duration as well as the mechanisms of sodium benzoate for clozapine-resistant schizophrenia.

Augmentation strategies for clozapine refractory schizophrenia: A systematic review and meta-analysis

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.

Cognitive behavioural therapy in clozapine-resistant schizophrenia (FOCUS): an assessor-blinded, randomised controlled trial

BACKGROUND

Although clozapine is the treatment of choice for treatment-refractory schizophrenia, 30-40% of patients have an insufficient response, and others are unable to tolerate it. Evidence for any augmentation strategies is scarce. We aimed to determine whether cognitive behavioural therapy (CBT) is an effective treatment for clozapine-resistant schizophrenia.

METHODS

We did a pragmatic, parallel group, assessor-blinded, randomised controlled trial in community-based and inpatient mental health services in five sites in the UK. Patients with schizophrenia who were unable to tolerate clozapine, or whose symptoms did not respond to the drug, were randomly assigned 1:1 by use of randomised-permuted blocks of size four or six, stratified by centre, to either CBT plus treatment as usual or treatment as usual alone. Research assistants were masked to allocation to protect against rater bias and allegiance bias. The primary outcome was the Positive and Negative Syndrome Scale (PANSS) total score at 21 months, which provides a continuous measure of symptoms of schizophrenia; PANSS total was also assessed at the end of treatment (9 months). The primary analysis was by randomised treatment based on intention to treat, for all patients for whom data were available. This study was prospectively registered, number ISRCTN99672552. The trial is closed to accrual.

FINDINGS

From Jan 1, 2013, to May 31, 2015, we randomly assigned 487 participants to either CBT and treatment as usual (n=242) or treatment as usual alone (n=245). Analysis included 209 in the CBT group and 216 in the treatment as usual group. No difference occurred in the primary outcome (PANSS total at 21 months, mean difference -0·89, 95% CI -3·32 to 1·55; p=0·48), although the CBT group improved at the end of treatment (PANSS total at 9 months, mean difference -2·40, -4·79 to -0·02; p=0·049). During the trial, 107 (44%) of 242 participants in the CBT arm and 104 (42%) of 245 in the treatment as usual arm had at least one adverse event (odds ratio 1·09, 95% CI 0·81 to 1·46; p=0·58). Only two (1%) of 242 participants in the CBT arm and one (<1%) of 245 in the treatment as usual arm had a trial-related serious adverse event.

INTERPRETATION

At 21-month follow-up, CBT did not have a lasting effect on total symptoms of schizophrenia compared with treatment as usual; however, CBT produced statistically, though not clinically, significant improvements on total symptoms by the end of treatment. There was no indication that the addition of CBT to treatment as usual caused adverse effects. The results of this trial do not support a recommendation to routinely offer CBT to all people who meet criteria for clozapine-resistant schizophrenia; however, a pragmatic individual trial might be indicated for some.

FUNDING

National Institute for Health Research Technology Assessment programme.

Cognitive behavioural therapy in clozapine-resistant schizophrenia (FOCUS): an assessor-blinded, randomised controlled trial

BACKGROUND

Although clozapine is the treatment of choice for treatment-refractory schizophrenia, 30-40% of patients have an insufficient response, and others are unable to tolerate it. Evidence for any augmentation strategies is scarce. We aimed to determine whether cognitive behavioural therapy (CBT) is an effective treatment for clozapine-resistant schizophrenia.

METHODS

We did a pragmatic, parallel group, assessor-blinded, randomised controlled trial in community-based and inpatient mental health services in five sites in the UK. Patients with schizophrenia who were unable to tolerate clozapine, or whose symptoms did not respond to the drug, were randomly assigned 1:1 by use of randomised-permuted blocks of size four or six, stratified by centre, to either CBT plus treatment as usual or treatment as usual alone. Research assistants were masked to allocation to protect against rater bias and allegiance bias. The primary outcome was the Positive and Negative Syndrome Scale (PANSS) total score at 21 months, which provides a continuous measure of symptoms of schizophrenia; PANSS total was also assessed at the end of treatment (9 months). The primary analysis was by randomised treatment based on intention to treat, for all patients for whom data were available. This study was prospectively registered, number ISRCTN99672552. The trial is closed to accrual.

FINDINGS

From Jan 1, 2013, to May 31, 2015, we randomly assigned 487 participants to either CBT and treatment as usual (n=242) or treatment as usual alone (n=245). Analysis included 209 in the CBT group and 216 in the treatment as usual group. No difference occurred in the primary outcome (PANSS total at 21 months, mean difference -0·89, 95% CI -3·32 to 1·55; p=0·48), although the CBT group improved at the end of treatment (PANSS total at 9 months, mean difference -2·40, -4·79 to -0·02; p=0·049). During the trial, 107 (44%) of 242 participants in the CBT arm and 104 (42%) of 245 in the treatment as usual arm had at least one adverse event (odds ratio 1·09, 95% CI 0·81 to 1·46; p=0·58). Only two (1%) of 242 participants in the CBT arm and one (<1%) of 245 in the treatment as usual arm had a trial-related serious adverse event.

INTERPRETATION

At 21-month follow-up, CBT did not have a lasting effect on total symptoms of schizophrenia compared with treatment as usual; however, CBT produced statistically, though not clinically, significant improvements on total symptoms by the end of treatment. There was no indication that the addition of CBT to treatment as usual caused adverse effects. The results of this trial do not support a recommendation to routinely offer CBT to all people who meet criteria for clozapine-resistant schizophrenia; however, a pragmatic individual trial might be indicated for some.

FUNDING

National Institute for Health Research Technology Assessment programme.

Amisulpride augmentation of clozapine for treatment-refractory schizophrenia: a double-blind, placebo-controlled trial

BACKGROUND

A second antipsychotic is commonly added to clozapine to treat refractory schizophrenia, notwithstanding the limited evidence to support such practice.

METHODS

The efficacy and adverse effects of this pharmacological strategy were examined in a double-blind, placebo-controlled, 12-week randomized trial of clozapine augmentation with amisulpride, involving 68 adults with treatment-resistant schizophrenia and persistent symptoms despite a predefined trial of clozapine.

RESULTS

There were no statistically significant differences between the amisulpride and placebo groups on the primary outcome measure (clinical response defined as a 20% reduction in total Positive and Negative Syndrome Scale score) or other mental state measures. However, the trial under recruited and was therefore underpowered to detect differences in the primary outcome, meaning that acceptance of the null hypothesis carries an increased risk of type II error. The findings suggested that amisulpride-treated participants were more likely to fulfil the clinical response criterion, odds ratio 1.17 (95% confidence interval 0.40-3.42) and have a greater reduction in negative symptoms, but these numerical differences were not statistically significant and only evident at 12 weeks. A significantly higher proportion of participants in the amisulpride group had at least one adverse event compared with the control group (p = 0.014), and these were more likely to be cardiac symptoms.

CONCLUSIONS

Treatment for more than 6 weeks may be required for an adequate trial of clozapine augmentation with amisulpride. The greater side-effect burden associated with this treatment strategy highlights the need for safety and tolerability monitoring, including vigilance for indicators of cardiac abnormalities, when it is used in either a clinical or research setting.

Amisulpride augmentation in clozapine-unresponsive schizophrenia (AMICUS): a double-blind, placebo-controlled, randomised trial of clinical effectiveness and cost-effectiveness

BACKGROUND

When treatment-refractory schizophrenia shows an insufficient response to a trial of clozapine, clinicians commonly add a second antipsychotic, despite the lack of robust evidence to justify this practice.

OBJECTIVES

The main objectives of the study were to establish the clinical effectiveness and cost-effectiveness of augmentation of clozapine medication with a second antipsychotic, amisulpride, for the management of treatment-resistant schizophrenia.

DESIGN

The study was a multicentre, double-blind, individually randomised, placebo-controlled trial with follow-up at 12 weeks.

SETTINGS

The study was set in NHS multidisciplinary teams in adult psychiatry.

PARTICIPANTS

Eligible participants were people aged 18-65 years with treatment-resistant schizophrenia unresponsive, at a criterion level of persistent symptom severity and impaired social function, to an adequate trial of clozapine monotherapy.

INTERVENTIONS

Interventions comprised clozapine augmentation over 12 weeks with amisulpride or placebo. Participants received 400 mg of amisulpride or two matching placebo capsules for the first 4 weeks, after which there was a clinical option to titrate the dosage of amisulpride up to 800 mg or four matching placebo capsules for the remaining 8 weeks.

MAIN OUTCOME MEASURES

The primary outcome measure was the proportion of 'responders', using a criterion response threshold of a 20% reduction in total score on the Positive and Negative Syndrome Scale.

RESULTS

A total of 68 participants were randomised. Compared with the participants assigned to placebo, those receiving amisulpride had a greater chance of being a responder by the 12-week follow-up (odds ratio 1.17, 95% confidence interval 0.40 to 3.42) and a greater improvement in negative symptoms, although neither finding had been present at 6-week follow-up and neither was statistically significant. Amisulpride was associated with a greater side effect burden, including cardiac side effects. Economic analyses indicated that amisulpride augmentation has the potential to be cost-effective in the short term [net saving of between £329 and £2011; no difference in quality-adjusted life-years (QALYs)] and possibly in the longer term.

LIMITATIONS

The trial under-recruited and, therefore, the power of statistical analysis to detect significant differences between the active and placebo groups was limited. The economic analyses indicated high uncertainty because of the short duration and relatively small number of participants.

CONCLUSIONS

The risk-benefit of amisulpride augmentation of clozapine for schizophrenia that has shown an insufficient response to a trial of clozapine monotherapy is worthy of further investigation in larger studies. The size and extent of the side effect burden identified for the amisulpride-clozapine combination may partly reflect the comprehensive assessment of side effects in this study. The design of future trials of such a treatment strategy should take into account that a clinical response may be not be evident within the 4- to 6-week follow-up period usually considered adequate in studies of antipsychotic treatment of acute psychotic episodes. Economic evaluation indicated the need for larger, longer-term studies to address uncertainty about the extent of savings because of amisulpride and impact on QALYs. The extent and nature of the side effect burden identified for the amisulpride-clozapine combination has implications for the nature and frequency of safety and tolerability monitoring of clozapine augmentation with a second antipsychotic in both clinical and research settings.

TRIAL REGISTRATION

EudraCT number 2010-018963-40 and Current Controlled Trials ISRCTN68824876.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 21, No. 49. See the NIHR Journals Library website for further project information.

No major influence of regular tobacco smoking on cerebrospinal fluid monoamine metabolite concentrations in patients with psychotic disorder and healthy individuals

Metabolism of the monoamines dopamine, serotonin and noradrenaline, is altered in the central nervous system of people with schizophrenia, and their major metabolites homovanillic acid (HVA), 5-hydroxyindoleacetic acid (5-HIAA) and 3-methoxy-4-hydroxyphenylglycol (MHPG), respectively, have been intensively studied as indirect measures of these neurotransmitters in cerebrospinal fluid (CSF). Regular tobacco smoking has been shown to alter neurotransmitter metabolism in the brain and studies have found CSF monoamine metabolite concentrations to be substantially lower in smokers. However, few studies investigating these monoamines in CSF have controlled for regular tobacco smoking. We investigated if regular tobacco smoking influences CSF HVA, 5-HIAA and MHPG concentrations in patients treated for psychotic disorders (n = 69) and healthy non-psychotic human volunteers (n = 200). After lumbar puncture CSF samples were analyzed with mass fragmentography. CSF HVA, 5-HIAA and MHPG concentrations did not significantly differ between smokers and non-smokers neither in patients, nor in healthy subjects, whereas back-length predicted HVA and 5-HIAA and antipsychotic medication MHPG concentrations. The results indicate that regular tobacco smoking has no significant effect on monoamine metabolite concentrations in CSF. This suggests that lack of controlling for regular tobacco smoking should not substantially violate the results in studies of the major monoamine metabolites in CSF.

Targeted neural network interventions for auditory hallucinations: Can TMS inform DBS?

The debilitating and refractory nature of auditory hallucinations (AH) in schizophrenia and other psychiatric disorders has stimulated investigations into neuromodulatory interventions that target the aberrant neural networks associated with them. Internal or invasive forms of brain stimulation such as deep brain stimulation (DBS) are currently being explored for treatment-refractory schizophrenia. The process of developing and implementing DBS is limited by symptom clustering within psychiatric constructs as well as a scarcity of causal tools with which to predict response, refine targeting or guide clinical decisions. Transcranial magnetic stimulation (TMS), an external or non-invasive form of brain stimulation, has shown some promise as a therapeutic intervention for AH but remains relatively underutilized as an investigational probe of clinically relevant neural networks. In this editorial, we propose that TMS has the potential to inform DBS by adding individualized causal evidence to an evaluation processes otherwise devoid of it in patients. Although there are significant limitations and safety concerns regarding DBS, the combination of TMS with computational modeling of neuroimaging and neurophysiological data could provide critical insights into more robust and adaptable network modulation.

Sodium valproate and clozapine induced neutropenia: A case control study using register data

BACKGROUND

The use of clozapine is limited due to the occurrence of neutropenia, and the rare but life threatening adverse event of agranulocytosis. There is little epidemiological research into clinical factors that may impact on this risk. We conducted a case control study examining the clinical risk factors for neutropenia patients treated with clozapine.

METHOD

A case-control study was conducted within a database of anonymised electronic clinical records. All patients who discontinued clozapine due to a neutropenic event were included as cases. Matched controls were selected from patients with a documented clozapine exposure at the time of the clozapine neutropenic event of the case patient, matched by duration of clozapine treatment.

RESULTS

136 cases and 136 controls were included. In multivariable analysis, the concurrent use of sodium valproate was associated with neutropenia (Odds Raito (OR) 2.28, 95%CI: 1.27-4.11, p=0.006). There was a dose-response effect, with greater associations for higher doses. Patients who discontinued clozapine due to neutropenia were more likely to be of black ethnicity (OR 2.99, p<0.001), were younger (t=5.86, df=267, p<0.001), and received lower doses of clozapine (t=-2.587, p=0.01) than those who did not develop neutropenia.

CONCLUSION

We identified an association between the concurrent use of sodium valproate and an increased risk of clozapine associated neutropenia. These results, taken in combination with the results from previous case series, suggest that the risk of clozapine associated neutropenia could be reduced by avoiding concurrent valproate treatment.