Autobiographical Memory Specificity in Major Depression Treated With Electroconvulsive Therapy

Autobiographical memory in major depression is characterized by reduced specificity, which reflects the tendency to summarize categories of events rather than recall specific instances of events situated in a time and place. This widely studied cognitive marker for depression has not been extensively examined in patients treated with electroconvulsive therapy (ECT).

We conducted a retrospective chart review of a naturalistic cohort of patients receiving a course of brief-pulse predominantly bitemporal ECT for a major depressive episode. Patients completed the recent life section of the Kopelman Autobiographical Memory Interview (AMI) at pre-ECT baseline, end of treatment course, and 3-month follow-up as part of routine clinical practice. Mood was assessed using the 24-item Hamilton Rating Scale for Depression.

We identified 48 patients (mean age, 61.6; female, 62.5%) meeting inclusion criteria. A total of 77.1% of patients responded to the ECT course, 29.7% subsequently relapsed. There were no significant changes over time on either AMI total score or semantic and episodic subscales. However, patients were markedly impaired on episodic autobiographical memory compared with the normative sample at all 3 assessment points, whereas personal semantic memory recall was normal. Specificity of episodic autobiographical memory at baseline did not predict response to ECT or likelihood of relapse.

We found reduced specificity of episodic autobiographical memory in depressed patients before ECT, which persisted at long-term follow-up despite significant improvement in mood. The finding of no detectable retrograde amnesia likely reflects lack of sensitivity of the recent life section of the AMI to detect ECT-induced changes.