Right Unilateral ECT Does Not Impair Cognitive Function in Treatment-Resistant Bipolar Depression

Long-term cognitive impairment was not observed over a 6-month period with right unilateral electroconvulsive therapy vs pharmacologic treatment.

The results of a study published in Bipolar Disorders indicate that right unilateral electroconvulsive therapy (ECT) does not reduce long-term general neurocognitive function in patients with treatment-resistant bipolar depression.

Jeanette Bjoerke-Bertheussen, a consulting psychiatrist in the division of psychiatry, Stavanger University Hospital in Norway, and colleagues conducted a prospective multicenter controlled trial in  patients with treatment-resistant bipolar depression (N=73) who were randomly assigned to either algorithm-based pharmacologic treatment or right unilateral ECT.

After the 6-week treatment period, patients in both groups received maintenance pharmacotherapy as recommended by their clinician. Neurocognitive functions were assessed at baseline and 6 months using the Measurement and Treatment Research to improve Cognition in Schizophrenia (MATRICS) Consensus Cognitive Battery, and autobiographical memory consistency was assessed with the Autobiographical Memory Interview-Short Form.

Both the baseline and 6-month assessments were completed by 26 patients. The MATRICS Consensus Cognitive Battery composite score improved by 4.1 points in both groups (P =0.042) from baseline to 6 months: from 40.8 to 44.9 and from 41.9 to 46.0 in the pharmacologic and ECT groups, respectively. The Autobiographic Memory Interview-Short Form consistency scores were reduced in both groups (72.3% vs 64.3% in the pharmacologic and ECT groups, respectively; P =.085).

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The high dropout rate encountered in this study is a limitation, possibly preventing detection of a significant difference between the two treatment groups in the cognitive test results at 6 months.

Compared with pharmacologic therapy, right unilateral ECT did not cause long-term impairment in neurocognitive function in this study. However, because of the small number of patients who completed the trial, the investigators stated that the results should be interpreted with caution. Furthermore, the investigators argued that the possibility of impaired autobiographical memory function acutely after right unilateral ECT must be communicated effectively to the patient before treatment so that the risk-benefit trade-off can be understood.


Bjoerke-Bertheussen J, Schoeyen H, Andreassen OA, et al. 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 [published online December 21, 2017]. Bipolar Disord.  doi:10.1111/bdi.12594