CET- REM (Correlating ECT Response to EEG Markers)

EEG on nights after ECT session will be recorded using the DREEM device. Sleep EEG data will also be acquired for a minimum of one night prior to the first ECT session, providing a true baseline measure. The DREEM device allows continuous recording of multichannel EEG

Closed loop acoustic stimulation will be enabled on the DREEM headband on a subset of study participants. The device delivers stimulation in phase with the upstroke of the EEG slow wave (STIM) to boost slow oscillation activity. The timing of this stimulus augments the expression of subsequent slow waves.

The Quick Inventory of Depressive Symptomatology-Self Report (QIDS-SR16) is a measure of depression symptom severity that has been validated for clinical and research use53. It is a standard self-report measurement completed by patients prior to each ECT session

A high-density 65-electrode EEG scalp electrode net (EGI/Philips) with Elefix conductive gel injected within Ag/AgCl electrode sensors is utilized to monitor brain activity during the ictal period

A board-certified epileptologist will review all seizures to assess seizure parameters, including duration of seizure and interval of PGES. Preprocessing of the PGES periods will be accomplished with band-pass filtering from 2 to 30 Hz with 1st order Butterworth filters.

Following EEG preprocessing of DREEM sleep recordings, SWA will be quantified using a custom-written MATLAB module as the average of total power spectral estimates within the 0.5-4 Hz frequency band in one minute intervals, during the first cycle of N3 sleep.