Retrograde amnesia and bilateral electroconvulsive therapy. Long-term follow-up.

Memory for past events was assessed in 43 patients who had been prescribed bilateral electroconvulsive therapy (ECT) for relief of depressive illness. Four memory tests of personal or public events were administered before ECT, shortly after the fifth treatment, one week after completion of treatment, and about seven months later. The results indicated that ECT can initially disrupt recall of events that occurred many years previously, but recovery of these memories was virtually complete by seven months after treatment. It was also clear that persisting memory loss for information acquired only a few days before treatment can occur. For information acquired one to two years prior to treatment, recovery was substantial, but the results suggested that some memory problems might persist for events that occurred during this time period.