Objectives: Electroconvulsive therapy (ECT) is the most effective treatment for drug-resistant depression (DRD). We estimated the short- and long-term effects of ECT on cognitive functions in patients with unipolar and bipolar DRD.
Methods: We investigated 63 patients (18 male, 45 female), aged 34-75 years. Cognitive assessments were performed before, immediately after 6-12 ECT sessions, and 3 months thereafter, using the Benton Visual Retention, Trail Making (TMT), Rey-Osterrieth Complex Figure (ROCF) tests, the Digit Span of the Wechsler Adult Intelligence Scale, and the Rey Auditory Verbal Learning (RAVLT), verbal fluency and Stroop tests.
Results: Immediately after ECT, a significant worsening was noted in some indices of memory and verbal fluency. However, 3 months after ECT, the indices of both RAVLT and verbal fluency significantly improved compared to baseline, and those of the Benton and ROCF were significantly better than before ECT. The Digit Span, Stroop and TMT were not affected by the treatment.
Conclusions: The negative effects of ECT on the reported measures of cognition are transient. After 3 months, the indices of memory were significantly better than before the treatment. In addition to its antidepressant effect in DRD, ECT may also exert a long-term favourable influence on some cognitive functions.
Keywords: Electroconvulsive therapy; bipolar depression; cognitive functions; drug-resistant depression; unipolar depression.