A sleep hormone might protect memory during electroconvulsive therapy
STUDY: Shahrokhi M et al, Basic and Clinical Neuroscience 2026
STUDY TYPE: Randomized controlled trial
FUNDING: Independent
Background
ECT is one of the most effective treatments for severe depression and bipolar depression, but up to 60% of patients have memory problems, particularly for events that happened around the treatment. Melatonin, a sleep hormone with antioxidant and anti-inflammatory properties in the brain, was tested here as a nightly adjunct during ECT.
The Study
- 46 inpatients with bipolar disorder scheduled for ECT; 23 received melatonin 3 mg nightly, 23 received placebo
- Treatment started 24 hours before the first session and continued 24 hours after the final session, roughly two weeks total
- Cognition was measured before and after each of the six ECT sessions using the Mini-Mental State Examination (MMSE), a 30-point screening tool for memory, attention, orientation, and language
Results
Melatonin-treated patients showed steady cognitive improvement across the ECT course. By the final session, their average MMSE score was 27.9, compared to 26.5 in the placebo group.
The strongest gains appeared in recall (+0.6 points vs. placebo) and attention/calculation (+0.5 points). Placebo patients showed no meaningful change from baseline on any session.
Blood pressure held steady in both groups. No hemodynamic concerns emerged.
Side Effects
Mild and transient: headache in one melatonin patient and daytime sleepiness in two. No one stopped treatment.
Limitations
Small, single center in Iran, no follow-up beyond final ECT session. The MMSE is a coarse tool; more sensitive memory tests might have captured finer effects. One prior trial found melatonin inferior to memantine for post-ECT cognition, so these results are not definitive.
Practice Implications
- As a low-cost, well-tolerated option, melatonin has potential here, but the study needs replication.
- Many brands do not have the stated ingredients. Here are lab-tested melatonin products.
— Chris Aiken, MD
Director, Psych Partners
Editor in Chief, Carlat Psychiatry Report
