Electroconvulsive therapy for negative symptoms in schizophrenia: a literature review from 2000 to 2021

Abstract

Negative symptoms in schizophrenia remain a clinical challenge with small effect sizes and evidence for pharmacological or psychotherapeutic treatment approaches. Studies suggest that electroconvulsive therapy (ECT) holds some promise as a treatment option of often persistent negative symptoms with clinically meaningful effects. This review summarizes the existing evidence on the efficacy of ECT on negative symptoms in patients with schizophrenia. Thirty-five publications were included in this literature review comprising 21 studies, two meta-analyses, eight reviews and four case reports. Conclusions should be interpreted cautiously, given the small number and methodological shortcomings of the included publications with a variation of study designs and missing standardized protocols. Implications for future research and practice are critically discussed. Recommendations are given to provide more evidence that will meet the clinical challenge of reducing the negative symptoms in schizophrenia. Study designs that focus explicitly on negative symptoms and assess patients over longer follow up periods could be helpful. Future research should include control groups, and possibly establish international multicentered studies to get a sufficient study population. Findings suggest that patients with schizophrenia resistant to pharmacological treatment might benefit from ECT. A risk and benefit assessment speaks in favour of the ECT treatment. Future practice of ECT should include a combination treatment with antipsychotics. Whereas the use of anaesthetics and electrode placement does not seem to play a role, the recommendation regarding frequency of ECT treatments is currently three times a week, For the assessment of negative symptoms the assessment tool should be chosen carefully.

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

“…However, patients with a depressive mood state at admission did show greater improvement in negative symptoms with ECT irrespective of whether they had a diagnosis of schizophrenia or schizoaffective disorder. This mixed finding provides insight into an area of inconsistency in prior reports of ECT in psychotic disorders, with some studies finding no effect of ECT on negative symptoms (12,33) while others have seen such an effect (15). These studies generally did not separate analyses by mood state or disorder.…”

“…Electroconvulsive therapy (ECT) has evidence of benefit in TRP, particularly for positive symptoms (10)(11)(12)(13). A 2006 Cochrane review estimated a NNT of 6 for treatment-refractory schizophrenia specifically (TRS) (14).…”

“…A 2006 Cochrane review estimated a NNT of 6 for treatment-refractory schizophrenia specifically (TRS) (14). Some evidence also suggests a possible effect on negative and general symptoms, as defined by the Positive and Negative Syndrome Scale (PANSS), though this finding is not consistent across studies (12,15). Systematic reviews have supported ECT as a safe and effective treatment in this population (10,12,16).…”

The Relationship Between the Recognition of Basic Emotions and Negative Symptoms in Individuals With Schizophrenia Spectrum Disorders – An Exploratory Study

“…There are, however, no sufficient treatment options for negative symptoms. The most often employed approaches as medication, psychotherapy, psychosocial interventions, and electroconvulsive therapy have only small effect sizes ( 38 – 40 ). A model of negative symptoms as the behavioral manifestation of altered social cognition has the potential to reveal areas of intact functioning, including domains of social cognition that remain unaffected by the illness, which novel treatments could rely upon to enhance the recovery of individuals with schizophrenia ( 1 ).…”

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“…There are, however, no sufficient treatment options for negative symptoms. The most often employed approaches as medication, psychotherapy, psychosocial interventions, and electroconvulsive therapy have only small effect sizes (38)(39)(40). A model of negative symptoms as the behavioral manifestation of altered social cognition has the potential to reveal areas of intact functioning, including domains of social cognition that remain unaffected by the illness, which novel treatments could rely upon to enhance the recovery of individuals with schizophrenia (1).…”