Improvement in Depressive Symptoms Is Not Associated with the Severity of Autobiographical Amnesia Following Electroconvulsive Therapy—A Preliminary Report from Naturalistic Prospective Observational Study

TL;DR

This study found that improvement in depression after ECT is not linked to memory loss severity, but suicidal thoughts at the start may predict worse memory issues.

Contribution

The study is the first to show no correlation between symptom improvement and memory loss severity after ECT in a naturalistic setting.

Findings

Depressive symptom improvement was not correlated with autobiographical memory loss (r = −0.14, p = 0.58).

Baseline suicidal ideation was associated with greater memory decline (r = −0.53, p = 0.016).

Bilateral ECT placement was linked to worse amnesia, though not significantly (p = 0.2).

Abstract

Background/Objectives: Electroconvulsive therapy (ECT) is used for treatment-resistant depression (TRD). Despite high effectiveness, its most prevalent side effect is memory loss, particularly autobiographical memory deficits. Some patients and physicians might associate post-ECT improvement in depressive symptoms with a higher risk of autobiographical amnesia or even consider this side effect ECT’s mechanism of action. Here, we aimed to study the association between improvement in depressive symptoms and the severity of autobiographical amnesia, as well as identify factors associated with the degree of memory loss. Methods: In this prospective naturalistic observational pilot study, we included 20 patients who underwent ECT for TRD. Attending psychiatrists decided on the electrode placement. Electrical dosage was based on the seizure-titration procedure. Depressive symptoms (Hamilton Depression Scale-21) and autobiographical memory (AMI-SF) were assessed before and after the full course of ECT. The correlation between symptomatic improvements and severity of memory loss was studied using Spearman’s correlation. Demographic and clinical baseline data were examined to look for associations with the decline in autobiographical memory. Results: Symptomatic improvement was not correlated with autobiographical memory loss (r = −0.14, p = 0.58) or any of its domains. Suicidal ideation at baseline was associated with a stronger decline in autobiographical memory (r = −0.53, p = 0.016). Patients treated with bilateral electrode placement had worse amnesia than those treated with right unilateral treatment, though the difference was not significant (MD = −17.4 vs. −13.1, p = 0.2). Conclusions: ECT improved depressive symptoms irrespective of autobiographical amnesia severity. Patients with suicidal ideation at baseline might experience worse post-ECT amnesia than those without.

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