Treatment-resistant depression (TRD) is a common cause of disability and one of the most
common psychiatric disorders worldwide.
Electroconvulsive therapy (ECT) is currently the most effective treatment for TRD. Recent
developments showed esketamine to be a rapid-acting and effective antidepressant drug and it
has been hailed as a breakthrough in treating TRD. Common treatment algorithms for TRD list
ECT as a treatment option, but esketamine has not yet found its exact position in those
algorithms.
To the investigators' knowledge, a longitudinal, randomized controlled trial comparing the
efficacy of ECT and intranasal esketamine in TRD patients has not been conducted.
Furthermore, the investigators intend to measure effects of ECT and intranasal esketamine on
brain connectivity and structure, using functional magnetic resonance imaging (fMRI).
In this study, inpatients with TRD at the University Hospital for Psychiatry I, Medical
University Innsbruck, will be randomized to ECT or intranasal esketamine. Short- and
medium-term treatment effects on functional and structural connectivity in the brain will be
determined using fMRI.