Author(s)

Maria Semkovska^1,2*, Tara O’Grady¹

¹University of Limerick, Limerick, Ireland.
²Trinity College Institute of Neuroscience, Dublin, Ireland.

Objective: To reliably quantify the autobiographical retrograde amnesia directly attributable to the effect of electroconvulsive therapy (ECT) independent from normal and depression-associated changes in autobiographical memory consistency. Method: By use of retrospective case-control study design, 19 severely depressed inpatients never treated with ECT who received pharmacotherapy (noECT group) were individually matched to similarly depressed 19 patients treated with standard, bitemporal electrode placement, ECT (B-ECT). The two groups were compared at Pre-Treatment, at Post-Treatment and at three months Follow-Up on their performance on the Semantic, Episodic-Extended and Episodic-Specific Components of the Columbia Autobiographical Memory Interview-Short Form (CAMI-SF). Effects of treatment group and time on the three components were tested with 2 × 3 repeated-measures analyses of variance. Depression severity, assessed using the Hamilton Depression Rating Scale, was investigated as possible covariate. To explore the results’ clinical significance, individual CAMI-SF performances were compared to available normative data. Results: At Pre-Treatment, the two groups were comparable on all three CAMI-SF components. In both groups, a significant effect of time explained decreased performance at Post-Treatment and Follow-Up on all components (p-values < 0.0001). No significant effect of treatment was observed on the Semantic and Episodic-Extended components (p > 0.16). The B-ECT retrieval consistency on the Episodic-Specific component was significantly worse at both Post-Treatment (p = 0.009) and Follow-Up (p = 0.012) relative to the noECT group. Ratios of impaired retrieval consistency were higher in the B-ECT group than in the noECT group at Post-Treatment only. On individual level, bitemporal ECT was associated with a clinically significant decrease in Episodic-Specific autobiographical memory recall at Post-Treatment in 37% of participants and, for about 26%, this specific impairment persisted for at least three months after end of treatment. Depression severity did not influence observed results. Conclusion: ECT-associated autobiographical amnesia is limited to specific personal episodes, does not affect all patients and is reversible for some.

Autobiographical Memory, Retrograde Amnesia, Depression, Electroconvulsive Therapy

Semkovska, M. and O’Grady, T. (2017) Unravelling Autobiographical Retrograde Amnesia Following Bitemporal Electroconvulsive Therapy: Effect of Treatment versus Effect of Time. Psychology, 8, 611-626. doi: 10.4236/psych.2017.84039.