Review of: Sarraf N et al, J Clin Neurosci 2020;74:146–150

Many patients hesitate to accept ECT because of the treatment’s adverse effects on cognitive function. Memantine (Namenda)—an NMDA receptor antagonist approved for the treatment of Alzheimer’s disease—has been shown to be more effective than placebo in preventing cognitive impairment due to ECT. A new study compares memantine with melatonin in depressed patients undergoing this treatment.

The authors conducted a randomized, double-blind trial to compare the effects of the two medications on patients with major depression who were undergoing ECT. Patients in the two medication groups were similar in demographic characteristics, duration of major depression, and scores on the Mini-Mental Status Examination (MMSE). All patients received right unilateral ECT with similar stimulus intensity, frequency, and duration. Melatonin was chosen as a comparative treatment because a previous study reported that it appeared effective at reducing ECT-induced cognitive impairment (Hamdieh M et al, Neurol Psych Brain Res 2017;24:30–34).

A total of 40 patients were randomized to receive either memantine 5 mg/day (n = 20) or melatonin 3 mg/day (n = 20), starting on the day of the first ECT treatment and ending on the day of the sixth treatment. ECT was administered every other day, and the trial lasted 12 days. The researchers administered the MMSE and item 3 of the MMSE—a measurement of immediate recall—a day before the first ECT treatment and again 24 hours after completion of the last ECT treatment.

At the conclusion of ECT, participants receiving memantine scored significantly higher than their baseline scores on both the MMSE and item 3 of the MMSE (p = 0.04 and p = 0.03, respectively). In contrast, participants’ scores in the melatonin group dropped on both measures compared to their baselines (MMSE, p = 0.3, and item 3 of the MMSE, p = 0.02).

Study subjects tolerated the medications well. A previous placebo-controlled study similarly found that memantine 5 mg/day reduced cognitive impairment following ECT (Abbasinazari M et al, Asian J Psychiatr 2015;15:5–9).

CHPR’s TAKE
Patients are often reluctant to accept ECT because of its effects on cognition. By prescribing memantine 5 mg/day, we may be able to forestall those effects and improve ECT’s acceptability. While previous research has found that melatonin also helps mitigate ECT-induced cognitive impairment, this study did not, possibly because the melatonin was administered in the morning and may have caused sedation.