RESUMEN
INTRODUCTION: The reversible electrochemical effects of electroconvulsive therapy (ECT) on specific areas of the brain enable the neuroanatomical bases of some cognitive functions to be studied. In research carried out on memory systems, a selective alteration of the declarative ones has been observed after treatment with ECT. Little work has been done to explore the differential alteration of the memory subsystems in patients with a high number of ECT sessions. AIM. To study the declarative and non declarative memory system in psychiatric patients submitted to maintenance ECT treatment, with a high number of previous ECT sessions. PATIENTS AND METHODS: 20 patients submitted to treatment with ECT (10 diagnosed as having depression and 10 with schizophrenia) and 20 controls, who were paired by age, sex and psychopathological diagnosis. For the evaluation of the declarative memory system, the Wechsler Memory Scale (WMS) logical memory test was used. The Hanoi Tower procedural test was employed to evaluate the non declarative system. RESULTS: Patients treated with ECT performed worse in the WMS logical memory test, but this was only significant in patients diagnosed as suffering from depression. No significant differences were observed in the Hanoi Tower test. CONCLUSIONS: A selective alteration of the declarative systems was observed in patients who had been treated with a high number of ECT sessions, while the non declarative memory systems remain unaffected.