ECT-induced cognitive side effects are associated with hippocampal enlargement

• Published in: Translational psychiatry 2021-10, Vol.11 (1), p.516-516, Article 516
• Main Authors: Argyelan, Miklos, Lencz, Todd, Kang, Simran, Ali, Sana, Masi, Paul J., Moyett, Emily, Joanlanne, Andrea, Watson, Philip, Sanghani, Sohag, Petrides, Georgios, Malhotra, Anil K.
• Format: Article
• Language: English
• Subjects: 59/57; 631/378/1595/1554; 692/53/2423; Behavioral Sciences; Biological Psychology; Cognition; Cognition Disorders; Electroconvulsive Therapy; Hippocampus - diagnostic imaging; Humans; Magnetic Resonance Imaging; Medicine; Medicine & Public Health; Neurosciences; Pharmacotherapy; Psychiatry
• ISSN: 2158-3188; 2158-3188
• DOI: 10.1038/s41398-021-01641-y

Electroconvulsive therapy (ECT) is of the most effective treatments available for treatment-resistant depression, yet it is underutilized in part due to its reputation of causing cognitive side effects in a significant number of patients. Despite intensive neuroimaging research on ECT in the past two decades, the underlying neurobiological correlates of cognitive side effects remain elusive. Because the primary ECT-related cognitive deficit is memory impairment, it has been suggested that the hippocampus may play a crucial role. In the current study, we investigated 29 subjects with longitudinal MRI and detailed neuropsychological testing in two independent cohorts ( N  = 15/14) to test if volume changes were associated with cognitive side effects. The two cohorts underwent somewhat different ECT study protocols reflected in electrode placements and the number of treatments. We used longitudinal freesurfer algorithms (6.0) to obtain a bias-free estimate of volume changes in the hippocampus and tested its relationship with neurocognitive score changes. As an exploratory analysis and to evaluate how specific the effects were to the hippocampus, we also calculated this relationship in 41 other areas. In addition, we also analyzed cognitive data from a group of healthy volunteers ( N  = 29) to assess practice effects. Our results supported the hypothesis that hippocampus enlargement was associated with worse cognitive outcomes, and this result was generalizable across two independent cohorts with different diagnoses, different electrode placements, and a different number of ECT sessions. We found, in both cohorts, that treatment robustly increased the volume size of the hippocampus (Cohort 1: t  = 5.07, Cohort 2: t  = 4.82; p