The cognitive model of negative symptoms: a systematic review and meta-analysis of the dysfunctional belief systems associated with negative symptoms in schizophrenia spectrum disorders

BACKGROUND

The hypothesized cognitive model of negative symptoms, proposed nearly twenty years ago, is the most prevalent psychological framework for conceptualizing negative symptoms in schizophrenia spectrum disorders (SSDs). The aim of this study was to comprehensively validate the model for the first time, specifically by quantifying the relationships between negative symptom severity and all related dysfunctional beliefs.

METHODS

A systematic search was conducted using MEDLINE and PsychINFO, supplemented by manual reviews of reference lists and Google Scholar. Eligible studies were peer-reviewed with data on the direct cross-sectional association between negative symptoms and at least one relevant dysfunctional belief in SSD patients. Screening and data extraction were completed by independent reviewers. Random-effects meta-analyses were performed to pool effect size estimates of z-transformed Pearson's r correlations. Moderators of these relationships, as well as subset analyses for negative symptom domains and measurement instruments, were also assessed.

RESULTS

Significant effects emerged for the relationships between negative symptoms and defeatist performance beliefs (k = 38, n = 2808), r = 0.23 (95% CI, 0.18-0.27), asocial beliefs (k = 8, n = 578), r = 0.21 (95% CI, 0.12-0.28), low expectancies for success (k = 55, n = 5664), r = -0.21 (95% CI, -0.15 - -0.26), low expectancies for pleasure (k = 5, n = 249), r = -0.19 (95% CI, -0.06 - -0.31), and internalized stigma (k = 81, n = 9766), r = 0.17 (95% CI, 0.12-0.22), but not perception of limited resources (k = 10, n = 463), r = 0.08 (95% CI, -0.13 - 0.27).

CONCLUSIONS

This meta-analysis provides support for the cognitive model of negative symptoms. The identification of specific dysfunctional beliefs associated with negative symptoms is essential for the development of precision-based cognitive-behavioral interventions.

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.

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.

Cognitive behavioural therapy plus standard care versus standard care plus other psychosocial treatments for people with schizophrenia

BACKGROUND

Cognitive behavioural therapy (CBT) is a psychosocial treatment that aims to help individuals re-evaluate their appraisals of their experiences that can affect their level of distress and problematic behaviour. CBT is now recommended by the National Institute for Health and Care Excellence (NICE) as an add-on treatment for people with a diagnosis of schizophrenia. Other psychosocial therapies that are often less expensive are also available as an add-on treatment for people with schizophrenia. This review is also part of a family of Cochrane Reviews on CBT for people with schizophrenia.

OBJECTIVES

To assess the effects of CBT compared with other psychosocial therapies as add-on treatments for people with schizophrenia.

SEARCH METHODS

We searched the Cochrane Schizophrenia Group's Study Based Register of Trials (latest 6 March, 2017). This register is compiled by systematic searches of major resources (including AMED, BIOSIS CINAHL, Embase, MEDLINE, PsycINFO, PubMed, and registries of clinical trials) and their monthly updates, handsearches, grey literature, and conference proceedings, with no language, date, document type, or publication status limitations for inclusion of records into the register.

SELECTION CRITERIA

We selected randomised controlled trials (RCTs) involving people with schizophrenia who were randomly allocated to receive, in addition to their standard care, either CBT or any other psychosocial therapy. Outcomes of interest included relapse, global state, mental state, adverse events, social functioning, quality of life and satisfaction with treatment. We included trials meeting our inclusion criteria and reporting useable data.

DATA COLLECTION AND ANALYSIS

We reliably screened references and selected trials. Review authors, working independently, assessed trials for methodological quality and extracted data from included studies. We analysed dichotomous data on an intention-to-treat basis and continuous data with 60% completion rate. Where possible, for binary data we calculated risk ratio (RR), for continuous data we calculated mean difference (MD), all with 95% confidence intervals (CIs). We used a fixed-effect model for analyses unless there was unexplained high heterogeneity. We assessed risk of bias for the included studies and used the GRADE approach to produce a 'Summary of findings' table for our main outcomes of interest.

MAIN RESULTS

The review now includes 36 trials with 3542 participants, comparing CBT with a range of other psychosocial therapies that we classified as either active (A) (n = 14) or non active (NA) (n = 14). Trials were often small and at high or unclear risk of bias. When CBT was compared with other psychosocial therapies, no difference in long-term relapse was observed (RR 1.05, 95% CI 0.85 to 1.29; participants = 375; studies = 5, low-quality evidence). Clinically important change in global state data were not available but data for rehospitalisation were reported. Results showed no clear difference in long term rehospitalisation (RR 0.96, 95% CI 0.82 to 1.14; participants = 943; studies = 8, low-quality evidence) nor in long term mental state (RR 0.82, 95% CI 0.67 to 1.01; participants = 249; studies = 4, low-quality evidence). No long-term differences were observed for death (RR 1.57, 95% CI 0.62 to 3.98; participants = 627; studies = 6, low-quality evidence). Only average endpoint scale scores were available for social functioning and quality of life. Social functioning scores were similar between groups (long term Social Functioning Scale (SFS): MD 8.80, 95% CI -4.07 to 21.67; participants = 65; studies = 1, very low-quality evidence), and quality of life scores were also similar (medium term Modular System for Quality of Life (MSQOL): MD -4.50, 95% CI -15.66 to 6.66; participants = 64; studies = 1, very low-quality evidence). There was a modest but clear difference favouring CBT for satisfaction with treatment - measured as leaving the study early (RR 0.86, 95% CI 0.75 to 0.99; participants = 2392; studies = 26, low quality evidence).

AUTHORS' CONCLUSIONS

Evidence based on data from randomised controlled trials indicates there is no clear and convincing advantage for cognitive behavioural therapy over other - and sometimes much less sophisticated and expensive - psychosocial therapies for people with schizophrenia. It should be noted that although much research has been carried out in this area, the quality of evidence available is mostly low or of very low quality. Good quality research is needed before firm conclusions can be made.

Changes in insight during treatment for psychotic disorders: a meta-analysis

OBJECTIVE

Poor insight, or awareness of illness, has a negative impact on the outcome of the psychosis, and is therefore a logical target for treatment. A meta-analysis of the effect of psychological and pharmacological treatments on insight in psychosis was conducted to give a comprehensive overview of effective interventions.

METHODS

An inclusive literature search (1975-April 2012) was performed in PubMed, ISI Web of Science, and EMBASE. The search terms used were "Insight", "Awareness", "Treatment", "Psychosis", "Therapy" and "Schizophrenia", no language specified. A cross-reference search of eligible articles was performed to identify studies not found in the computerized search. Effect sizes (Cohen's d) of each study and overall were calculated under a random effects model with 95% confidence intervals.

RESULTS

Our literature search resulted in approximately 350 abstracts. Nineteen RCTs that examined treatment effects on insight in patients with psychotic disorders were included. Overall, the interventions had a medium effect (d=.34, 95% CI, 0.12-0.57). The effects of CBT, adherence therapy and psycho-education were small to moderate, but not significant, probably due to a lack of power. There were insufficient data to allow a statistical evaluation of the effect of skills training, medication, video-confrontation and comprehensive intervention programs consisting of multiple components. Few adverse effects on mood were documented but this aspect was seldom quantified.

CONCLUSION

There is a paucity of studies providing data regarding treatment for impaired insight in psychosis. Nevertheless, from the published literature in this meta-analysis, we can confirm that it is a potential therapeutic target and that it is amenable to improvement. Comprehensive intervention programs consisting of multiple components may be particularly promising. Improvements in insight did not seem to be associated with increased depression.