Autobiographical memory after electroconvulsive therapy: systematic review and meta-analysis

Abstract

Background

Electroconvulsive therapy (ECT) is the most effective treatment of major depression, but autobiographical memory loss may limit its use. Despite previous attempts to synthesise the literature, the nature of autobiographical memory loss after ECT is still debated.

Aims

To provide an overview of the effect of ECT on autobiographical memory in patients with depression and explore whether the effect is temporary or permanent. Furthermore, we wanted to analyse if ECT parameters or clinical information are associated with this effect.

Method

PubMed, EMBASE, PsycINFO and Web of Science databases were searched on 26 January 2024. We included longitudinal studies measuring autobiographical memory before and after ECT in patients with depression compared to patients with depression receiving other treatment or healthy controls. Synthesis approach was a meta-analysis. PROSPERO ID: CRD42021267901.

Results

Nine studies were included (432 patients, 173 controls). At post-ECT, we found that ECT patients had larger autobiographical memory loss than controls (standardised mean difference (SMD) = 0.55; 95% CI = 0.35–0.75). Right unilateral (RUL) ECT entailed a small effect on autobiographical memory (SMD = 0.32; 95% CI = 0.06–0.57), while bilateral ECT yielded a large effect (SMD = 0.82; 95% CI = 0.49–1.15). Higher age was associated with smaller effect. Autobiographical memory was stable at long-term follow-up.

Conclusions

The studies suggest that ECT causes autobiographical memory loss in patients with depression. Results also suggest that lost memories are not regained. Furthermore, results support that RUL ECT is less detrimental to autobiographical memory. Strangely, a higher age might mitigate the autobiographical memory loss. Our findings are limited by studies being mainly observational and generally consisting of small sample sizes. Future studies should prioritise long-term follow-up assessments of autobiographical memory.