Multifactorial determinants of the neurocognitive effects of electroconvulsive therapy

Abstract

For many patients with neuropsychiatric illnesses, standard psychiatric treatments with mono or combination pharmacotherapy, psychotherapy, and transcranial magnetic stimulation are ineffective. For these patients with treatment-resistant neuropsychiatric illnesses, a main therapeutic option is electroconvulsive therapy (ECT). Decades of research have found ECT to be highly effective; however, it can also result in adverse neurocognitive effects. Specifically, ECT results in disorientation after each session, anterograde amnesia for recently learned information, and retrograde amnesia for previously learned information. Unfortunately, the neurocognitive effects and underlying mechanisms of action of ECT remain poorly understood. The purpose of this paper was to synthesize the multiple moderating and mediating factors that are thought to underlie the neurocognitive effects of ECT into a coherent model. Such factors include demographic and neuropsychological characteristics, neuropsychiatric symptoms, ECT technical parameters, and ECT-associated neurophysiological changes. Future research is warranted to evaluate and test this model, so that these findings may support the development of more refined clinical seizure therapy delivery approaches and efficacious cognitive remediation strategies to improve the use of this important and widely used intervention tool for neuropsychiatric diseases.

Figure 1. Conceptual Model of How Electroconvulsive Therapy Affects Neurocognitive Function

This figure shows the conceptual model of the relationship among neuropsychiatric disease, electroconvulsive therapy, altered cortical excitability/neural oscillations, demographic factors, and neurocognitive function. ECT=Electroconvulsive Therapy

Figure 2. Proposed Causal Model of How Electroconvulsive Therapy Affects Memory Function

This figure shows a causal model of how electroconvulsive therapy negatively impacts memory function in patients with major depressive disorder through its intermediate alterations in cortical excitability and disruption of long-term potentiation (LTP). ECT=Electroconvulsive Therapy