Electroconvulsive therapy and autobiographical memory in patients with treatment-resistant depression

Electroconvulsive therapy (ECT) is the most effective treatment for drugresistant depression. In most studies, cognitive functions including working and semantic memory showed only transient impairment after ECT. However, the deficits of episodic (autobiographical) memory were demonstrated to be long-lasting.

We investigated autobiographical memory in 20 patients (8 male, 12 female), aged 21-64 years, with drug-resistant depression, treated with ECT, using the Polish adaptation of the Autobiographical Memory Interview-Short Form (AMI-SF). The assessments were performed before, immediately after 10-12 ECT sessions, and 3 months thereafter.

Before the ECT, the mean severity of depression was 30 ± 6 points on the 17-item Hamilton Depression Rating Scale and the treatment produced a significant clinical improvement in all patients. The indices of autobiographical memory, as assessed by the AMI-SF, were significantly lower immediately after ECT and 3 months thereafter. The impairment in autobiographical memory did not show correlation with clinical improvement and with any other clinical factors.

The results obtained in patients with drug-resistant depression confirm that ECT treatment produces a significant impairment of autobiographical memory persisting also three months after the procedure, suggesting that it may be the most important adverse cognitive effect of the ECT.