Negative Symptoms in Schizophrenia Clinical Trial
Official title:
Metacognitive Training for Negative Symptoms (MCT Minus)
There is a clear rationale for developing interventions targeting negative symptoms of schizophrenia as these are a stronger indicator of current and future functioning than positive symptoms and because they respond poorly to medication and existing psychological interventions. This is reflected in the NIMH-MATRICS consensus statement that emphasised that persistent negative symptoms represent an unmet therapeutic need for patients suffering from schizophrenia. The purpose of this study is to evaluate, in a scientific manner, the intervention developed by Swanson et al. 2021: Metacognitive Training (MCT) Minus. The MCT was adapted to target negative symptoms in psychotic disorders (e.g. schizophrenia, schizoaffective or non-affective functional psychosis) as the original version of the intervention focused exclusively on positive symptoms. The specific aim is to study whether MCT Minus is a promising treatment for the intended population in terms of reductions in negative symptoms, severity of defeatist attitudes, internalised stigma, and depression as well as improvements in reflective ability and overall functioning. The research will add to existing research by identifying and measuring potential mechanisms of change for negative symptoms (i.e., defeatist attitudes, reflective functioning, stigma and depression). It will also add to the existing evidence base by measuring whether the cognitive biases addressed in MCT lead to changes in the wider conceptualisation of metacognition used elsewhere and whether the promising results seen in the feasibility study of MCT Minus can be replicated in a randomised controlled trial (RCT) with a control group and a blinded assessor. The researchers also hope to replicate the findings of a previous study, where MCT was found to be related to the modulation of default-mode network (DMN) homogeneity in schizophrenia, an area thought to be involved in self- and other-reflectivity.
Introduction: While clinicians tend to focus on positive symptoms as primary treatment targets in schizophrenia, patients prioritize the treatment of depressive and negative symptoms. Persistent negative symptoms are experienced by approximately 20%-40% of individuals diagnosed with schizophrenia. Current research indicates that negative symptoms are independent from positive symptoms, depression, cognitive dysfunctions, and disorganization. However, neither medication nor existing psychosocial interventions have proven to be efficacious in reducing negative symptoms. Consequently, authors have highlighted the need for better understanding of treatment mechanisms underpinning psychological interventions that directly target negative symptoms. Psychological conceptualizations suggest that negative symptom expression can, in some cases, be understood as a response to adverse experiences. For example, Beck et al.'s cognitive model suggests that negative symptoms emerge from a process where individuals adopt coping strategies of 'shutting down' the cognitive-affective experience. This allows individuals to cope with overwhelming or aversive situations in the short term but leads to a reliance on negative symptoms (including social withdrawal, avolition, and diminished expression) to reduce exposure to, and impact of, negative experiences in the longer term. From an attachment framework, Griffiths and McLeod (2019) suggest that negative symptoms may be seen 'as responses involving emotional and social withdrawal that emerge from threats to self-security'. If negative symptoms can be understood within cognitive and developmental frameworks, it may be possible to develop theoretically driven interventions for their treatment. A cognitive model of negative symptoms: Negative symptoms are associated with low expectations of future success, asocial beliefs, a reduced sense of self-efficacy, negative self-concepts, defeatist performance beliefs and self-stigma. The cognitive model therefore proposes that negative symptoms might be caused and maintained by dysfunctional beliefs arising as a consequence of repeated failures and setbacks. These appraisals might include negative beliefs about social affiliations; low expectations of pleasure, success and acceptance; defeatist beliefs about performance; and a perception of limited resources. The self-perception, and perceived self-efficacy, of individuals diagnosed with schizophrenia may also be influenced by self-stigmatizing views of their mental illness. It might be that these factors result in hypervigilance to perceived criticism. Longitudinal studies have shown support for the cognitive model as defeatist performance attitudes and asocial beliefs are found to predict future negative symptoms. Metacognition and psychosis: Metacognition was initially referred to as the capacity to think about and monitor one's mental processes. However, the definition has broadened in contemporary research, ranging 'from discrete processes involving noticing specific thoughts and feelings to more synthetic acts in which information is integrated into complex representations of the self and others'. This has given rise to interventions targeting metacognitive processes, some of which have been specifically developed for psychosis e.g., metacognitive training (MCT); metacognitive reflection and insight therapy (MERIT), while others have been modified for this population. MCT is based on the premise that cognitive biases play a role in the development and maintenance of psychotic symptoms which can be alleviated by targeting underlying cognitive processes. The aims are to gain insight and to learn practical strategies to manage distressing symptoms. MCT has been shown to reduce delusions and positive symptoms and improve cognitive insight and biases. Preliminary evidence also suggests effects on quality of life and illness insight. Several authors highlight the links between negative symptoms and compromised capacity for self/others mental state processing. There is evidence that suggests a link between metacognition and negative symptoms as limitations in complex metacognitive processes predict negative symptoms in first episode psychosis and in more chronic samples, even after controlling for defeatist beliefs, affect recognition and neurocognitive functioning. Metacognitive deficits are also associated with concurrent and future negative symptoms when controlling for verbal memory and education. Interestingly, self-reflection in itself has been found to mediate the relationship between neurocognition and negative symptoms (especially for deficits in capacity to communicate about internal states, so called diminished expression) while interpersonal cognitive differentiation (i.e., the ability to construe one's experiences as either similar or different from others' experiences) has been found to mediate the pathway between self-reflectivity and negative symptoms. This suggests that negative symptom reduction may at least partially depend on improved metacognitive capacity and that a metacognitive intervention specifically targeting negative symptoms may be beneficial. Swanson et al. (2021) therefore adapted MCT for negative symptoms to assess the acceptability and feasibility of the intervention, examine variable change over the course of the intervention and carry out a preliminary investigation of putative mechanisms of change. The current project is a further evaluation of this, where the researchers hope to achieve similarly encouraging results in a randomised controlled trial (RCT) with a control group and blinding. The researchers also hope to replicate the findings of a previous study where MCT was found to be related to the modulation of default-mode network (DMN) homogeneity in schizophrenia, an area thought to be involved in self- and other-reflectivity. Importantly, it was found that high network homogeneity levels at baseline in the bilateral superior medial prefrontal cortex could predict symptomatic improvement after 8 weeks of drug plus psychotherapy treatment; this illustrates that a more developed understanding of the biological mechanisms underlying negative symptoms would allow us to identify patients that would benefit from each type of treatment and, through that, change the prognosis and treatment outcomes of the condition. Significance and scientific novelty: Research funding has been given for a RCT to evaluate the intervention trialled by Swanson et al, 2021 in a more rigorous and scientific manner. Given our limited understanding of negative symptoms and how to treat them, the study would be of both significance and scientific novelty. To fully understand the biological mechanisms behind negative symptoms is essential to be able to develop future treatment options and to identify patients that would benefit from each type of treatment. A more thorough understanding of schizophrenia would decrease the heterogeneity of the condition which would have vast implications for how individuals diagnosed with schizophrenia are treated both in society and in the healthcare setting. Previous results: Two articles (which were based on the main researcher's doctoral thesis at Edinburgh University with funding from National Health Service (NHS) Lothian) have been published in Clinical Psychology and Psychotherapy. ;