Thesis defense Peter Mulders (Donders series 435)

26 May 2020

Promotors: prof. dr. I. Tendolkar, prof. dr. C. Beckmann
Co-promotor: dr. P. van Eijndhoven

Current Connections: Brain patterns in electroconvulsive therapy

Major depressive disorder is one of the leading causes of disability worldwide, and up to a third of patients will fail to respond to conventional pharmaco- or psychotherapy. Electroconvulsive therapy (ECT) is the single most potent treatment available for major depressive disorder, inducing remission even in those treatment-resistant patients. Although it has been used to treat patients for close to 80 years, little is known about its mechanism of action.

ECT affects both structure and function of the brain, and these effects can be found throughout the cortex and subcortical regions. In the cortical midline, it restores connectivity within the default mode network which is changed in the depressed brain.  This network has consistently been implicated in the pathophysiology of depression and relates to rumination and memory impairment as seen in depression. Structurally, cortical volume increases in most areas of the brain after ECT, with a more pronounced increase in lateral and mediotemporal regions.

No single region or change adequately explain ECT’s clinical efficacy, but these effects are strongly related to the full pattern of changes. The most important regions within this model are those that are also affected in the depressed patient, most notably the medial prefrontal cortex (including anterior cingulate cortex), dorsolateral prefrontal cortex, the precuneus and the basal ganglia. We show how both structure and function change through ECT in these depression-related regions, and how we can use novel neuroimaging and statistical methods to further our understanding of ECT’s antidepressive properties.