Absence of of longer reorientation times in patients undergoing ECT and concomitant treatment with lithium
Ricardo Martins-Ascencao 1*, Nuno Rodrigues-Silva 1, 2, 3, Nuno Trovão 1, 4
1Faculty of Health Sciences - University of Beira Interior, Covilhã, Portugal, 2ECT Unit - Trofa Saúde Senhor do Bonfim Hospital, Vila do Conde, Portugal, 3Conde Ferreira Healthcare Center, Porto, Portugal, 4Department of Psychiatry and Mental Health - Cova da Beira University Hospital Center, Covilhã, Portugal
Received: September 3, 2020; Revised: November 9, 2020; Accepted: November 13, 2020; Published online: November 13, 2020.
© The Korean College of Neuropsychopharmacology. All rights reserved.

Objective: Lithium is a drug of choice in the treatment of bipolar disorder and refractory depressive disorders. However, previous research suggests lithium has a negative cognitive impact in recovery from electroconvulsive therapy (ECT) and a higher risk of delirium, so patients are often required to stop taking lithium before ECT, despite risk of relapse. We studied the cognitive impact of serum lithium levels in patients undergoing ECT. Methods: This was an observational prospective study. Serum lithium levels, thyroid and biochemical parameters were measured prior to each ECT session. Time elapsed from the anesthetic induction to the electrical stimulus and then to the patients’ reorientation was recorded, as well as the motor seizure duration and EEG seizure duration. A statistical analysis using a linear mixed model was run while adjusting for confounding factors. Results: Ten participants underwent a total of 86 ECT sessions (41% right unilateral ultrabrief pulse, and 59% bilateral brief pulse). A negative interaction between lithium levels and reorientation time was found among those doing bilateral brief pulse ECT. No association was observed in patients doing unilateral ultrabrief pulse ECT. No significant relationship was observed between lithium and both motor and EEG-assessed seizure duration. Conclusion: This study suggests that low to moderate serum lithium levels (<0.7 mmol/L) might have no harmful cognitive effects in patients under right unilateral ultrabrief pulse ECT and bilateral brief pulse ECT.
Keywords: Lithium, Electroconvulsive therapy, Orientation time, Cognitive dysfunction, Confusion