Steven Dubovsky, MD

In depressed patients, a memory of an emotionally aversive story that was reactivated immediately before electroconvulsive therapy was impaired a day later.

Researchers in the Netherlands examined whether electroconvulsive therapy (ECT) could disrupt reconsolidation of reactivated aversive emotional memories. Participants were 42 patients with unipolar depression receiving unilateral or bilateral ECT with etomidate anesthesia (mean age, 57). Participants were either at the end of acute-phase ECT or in a maintenance course.

Patients were shown two slideshows with audio of emotionally aversive stories. A week later, memory for one or the other story was reactivated in the participants, who viewed part of the first slide and were then asked questions promoting recall of the story. Participants were assigned to ECT immediately after memory reactivation, followed by memory testing 1 day later; post-reactivation ECT plus memory testing about 100 minutes afterwards; or no post-reactivation ECT, but with memory testing a day after reactivation.

Memory of the “reactivated” story was impaired when tested a day after ECT but not 90 minutes post-ECT. In the group that did not undergo post-reactivation ECT, memory of the reactivated story was better than the “not-reactivated” one. No group differences were seen in memory for the not-reactivated story. General differences in cognition or learning did not explain these differences.

Citation(s):

Kroes MCW et al. An electroconvulsive therapy procedure impairs reconsolidation of episodic memories in humans. Nat Neurosci 2013 Dec 22; [e-pub ahead of print].