Concurrent validity of negative symptom assessments in treatment refractory schizophrenia: relationship between interview-based ratings and inpatient ward observations

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.

Negative symptoms in schizophrenia: a study in a large clinical sample of patients using a novel automated method

OBJECTIVES

To identify negative symptoms in the clinical records of a large sample of patients with schizophrenia using natural language processing and assess their relationship with clinical outcomes.

DESIGN

Observational study using an anonymised electronic health record case register.

SETTING

South London and Maudsley NHS Trust (SLaM), a large provider of inpatient and community mental healthcare in the UK.

PARTICIPANTS

7678 patients with schizophrenia receiving care during 2011.

MAIN OUTCOME MEASURES

Hospital admission, readmission and duration of admission.

RESULTS

10 different negative symptoms were ascertained with precision statistics above 0.80. 41% of patients had 2 or more negative symptoms. Negative symptoms were associated with younger age, male gender and single marital status, and with increased likelihood of hospital admission (OR 1.24, 95% CI 1.10 to 1.39), longer duration of admission (β-coefficient 20.5 days, 7.6-33.5), and increased likelihood of readmission following discharge (OR 1.58, 1.28 to 1.95).

CONCLUSIONS

Negative symptoms were common and associated with adverse clinical outcomes, consistent with evidence that these symptoms account for much of the disability associated with schizophrenia. Natural language processing provides a means of conducting research in large representative samples of patients, using data recorded during routine clinical practice.

Management of negative symptoms of schizophrenia

Persistent negative symptoms are a major cause of chronic disability in schizophrenia. The primary management approach for negative symptoms is use of atypical antipsychotics. Among atypical antipsychotics, clozapine produces the most robust reductions in negative symptoms. Lesser degrees of reduction are observed with risperidone and olanzapine. However, it remains unclear whether these agents treat core negative symptoms of schizophrenia, or simply induce less secondary psychopathology. A second approach for treatment of persistent negative symptoms is the use of N-methyl-D-aspartate (NMDA) receptor-stimulating agents, such as glycine, D-serine, or D-cycloserine. Significant benefit of these agents has been observed in combination with both conventional and newer atypical antipsychotics. Whether or not these agents are effective in combination with clozapine remains an open question, and large scale multicenter clinical trials are ongoing.