Retrograde Amnesia following ECT for Depression: New Analysis From Ireland

 Out on PubMed, from authors in Ireland and England, is this paper:

Retrograde amnesia following electroconvulsive therapy for depression: propensity score analysis.

Jelovac A, Landau S, Gusciute G, Noone M, Kavanagh K, Carton M, McCaffrey C, McDonagh K, Doody E, McLoughlin DM.BJPsych Open. 2025 Apr 4;11(3):e81. doi: 10.1192/bjo.2025.25.PMID: 40181761

The abstract is copied below:

Retrograde amnesia for autobiographical memories is a commonly self-reported cognitive side-effect of electroconvulsive therapy (ECT), but it is unclear to what extent objective performance differs between ECT-exposed and ECT-unexposed patients with depression. We investigated the association between exposure to brief-pulse (1.0 ms) bitemporal or high-dose right unilateral ECT and retrograde amnesia at short- and long-term follow-up, compared with inpatient controls with moderate-to-severe depression without lifetime exposure to ECT and receiving psychotropic pharmacotherapy and other aspects of routine inpatient care. In propensity score analyses, statistically significant reductions in autobiographical memory recall consistency were found in bitemporal and high-dose right unilateral ECT within days of an ECT course and 3 months following final ECT session. The reduction in autobiographical memory consistency was substantially more pronounced in bitemporal ECT. Retrograde amnesia for items recalled before ECT occurs with commonly utilised ECT techniques, and may be a persisting adverse cognitive effect of ECT.

Keywords: Electroconvulsive therapy; autobiographical memory; bipolar type I or II disorders; depressive disorders; retrograde amnesia.

The article is here.

And from the text:

This is a sophisticated data analysis from a premier ECT research group. The findings are useful and not surprising, but certainly open to interpretation in the clinical realm. There is no question that bilateral ECT has greater memory effects than right unilateral ECT; the authors note that more urgent clinical scenarios still warrant consideration of bilateral electrode placement. The data from the non-ECT-exposed depressed control group are particularly informative and interesting.

Measurement of memory loss at three months maybe termed "persistent" but how long it lasts is unclear. And most importantly, the effects on quality of life are unknown. 

Memories are precious and we should of course preserve them in our patients whenever possible with appropriate ECT technique modifications; but for the most severely ill patients, perhaps up to 50% of typical ECT clinic populations, bilateral electrode placement should remain an option, either to switch to when RUL is not adequately effective after several treatments or as an initial choice when speed of recovery is paramount. 

Finally, the authors' suggestion that possible differences in cognitive outcomes between ECT types should be discussed as part of the ECT consent process is good, common-sense practice. Kudos to these researchers for their thoughtful presentation of these data.