Right unilateral electroconvulsive therapy does not cause more cognitive impairment than pharmacologic treatment in treatment-resistant bipolar depression: A 6-month randomized controlled trial follow-up study

Objectives Electroconvulsive therapy is an effective treatment for bipolar depression, but there are concerns about whether it causes long-term neurocognitive impairment. Methods In this multicenter randomized controlled trial, in-patients with treatment-resistant bipolar depression were randomized to either algorithm-based pharmacologic treatment or right unilateral electroconvulsive therapy. After the 6-week treatment period, all of the patients received maintenance pharmacotherapy as recommended by their clinician guided by a relevant treatment algorithm. Patients were assessed at baseline and at 6 months. Neurocognitive functions were assessed using the Measurement and Treatment Research to Improve Cognition in Schizophrenia (MATRICS) Consensus Cognitive Battery, and autobiographical memory consistency was assessed using the Autobiographical Memory Interview-Short Form. Results Seventy-three patients entered the trial, of whom 51 and 26 completed neurocognitive assessments at baseline and 6 months, respectively. The MATRICS Consensus Cognitive Battery composite score improved by 4.1 points in both groups (P = .042) from baseline to 6 months (from 40.8 to 44.9 and from 41.9 to 46.0 in the algorithm-based pharmacologic treatment and electroconvulsive therapy groups, respectively). The Autobiographical Memory Interview-Short Form consistency scores were reduced in both groups (72.3% vs 64.3% in the algorithm-based pharmacologic treatment and electroconvulsive therapy groups, respectively; P = .085). Conclusions This study did not find that right unilateral electroconvulsive therapy caused long-term impairment in neurocognitive functions compared to algorithm-based pharmacologic treatment in bipolar depression as measured using standard neuropsychological tests, but due to the low number of patients in the study the results should be interpreted with caution. Trial registration ClinicalTrials.gov: NCT00664976.