A 55-year-old woman with treatment-resistant major depressive disorder with psychotic features undergoes ECT. Which of the following is the MOST common cognitive side effect of bilateral ECT versus right unilateral ECT?

• A Greater anterograde and retrograde amnesia with bilateral vs. right unilateral ECT ✓
• B Persistent anterograde amnesia lasting more than 6 months
• C Permanent procedural memory loss
• D Bilateral ECT has fewer cognitive effects but lower efficacy

Explanation

ECT causes transient cognitive side effects including anterograde amnesia (difficulty learning new information after treatment) and retrograde amnesia (difficulty recalling events before treatment). Bilateral ECT has greater anterograde and retrograde amnesia compared to right unilateral ECT at standard doses, though bilateral ECT has faster onset of antidepressant response and marginally higher efficacy. Right unilateral ECT at higher doses (≥6 times seizure threshold) approaches bilateral ECT in efficacy with fewer cognitive effects. Cognitive effects are typically transient, resolving within weeks to months, though some autobiographical memory gaps may persist.

Reference: Kaplan & Sadock's Synopsis of Psychiatry, 11th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.