This open label investigation further evaluates the safety, efficacy and potential mechanisms of action of a new form of electroconvulsive therapy (ECT). The investigators have recently completed preliminary open-label studies with FEAST, first at Columbia University, and then at the Medical University of South Carolina in Charleston (Nahas et al., 2013b). The investigators have published the outcomes of the first 17 patients studied. One patient withdrew from the study after a single titration session. After the course of FEAST (median 10 sessions), there was a 46.1 + 35.5% improvement in Hamilton Rating Scale for Depression (HRSD24) scores compared to baseline (33.1 + 6.8, 16.8 + 10.9; P < 0.0001). Eight of 16 patients met response criteria (≥50% decrease in HRSD24) and 5/16 met remission criteria (HRSD24≤10). Patients achieved full re-orientation (4 of 5 items correct) in 5.5 + 6.4 min (median time = 3.6 min), timed from when their eyes first opened after treatment. The investigators have now studied 18 more patients (see results below), and we are completing the study in the original IDE with another two more patients still to enroll.

This work allowed us to refine the treatment. For example, the investigators selectively modified the electrode geometry to decrease interelectrode resistance. Additionally the investigators modified the titration schedule, now only administering a standard 800 ma ultrabrief pulse, and thus no longer titrating in the current domain.

In this next proposed trial we will continue to gather efficacy and safety data, and compare these to a parallel non-randomized group receiving ECT standard of care.

ECT is typically delivered in a dynamically adaptive manner, with each person having a different number of treatments, averaging between 8-12 treatment over 4-5 weeks. We thus have to use imprecise time points such as 'at the end of the acute treatment course' rather than specified dates or visits.

This study will provide preliminary evaluation of the following:

1. Further characterization of the efficacy of FEAST and the safety of the treatment.

   1. The primary efficacy measure will be the 24-item Hamilton Rating Scale for Depression. The changes in these scores from before to immediately following the treatment course (typically after 4 weeks) will be compared in patients treated with the FEAST methodology and matched to nonrandomized patients at our facilities who were treated with conventional ECT methods (ultrabrief right unilateral [RUL] ECT).
   2. Acute and subacute cognitive side effects following FEAST will be assessed with a brief neuropsychological battery. The primary acute measures will be the time to return of orientation following seizure induction. The primary subacute measures will be assessment of retrograde amnesia for autobiographical information. The neuropsychological measures will be compared in the patients treated with the FEAST methodology (under this IDE) and matched (but nonrandomized) patients who are treated with conventional ECT methods (also covered under this IDE).
   3. Safety will also be determined by examining the number and frequency of serious adverse advents and adverse events.

2. Characterization of the focal nature of the seizure onset with FEAST and RUL ECT. We will use two main methods to address the issue of focality.

   1. Resting state fMRI before and after a course of FEAST (or conventional RUL ECT). We will address whether FEAST causes changes in hyper connected prefrontal cortical subcortical networks, and whether such an effect is more restricted to prefrontal cortex with FEAST relative to conventional RUL ECT.
   2. Peri-ictal EEG acquired immediately before, during and immediately after the FEAST seizure. We will acquire this in all patients at all treatment sessions. Again, for comparison, we will use identical EEG acquisition methods in patients treated with conventional RUL ECT.

Inclusion Criteria:

• Diagnosis of Major Depressive Episode
• Pretreatment Hamilton Depression Score >21
• ECT indicated
• Willing and able to give informed consent

Exclusion Criteria:

• History of schizophrenia, schizoaffective disorder, other functional psychosis, or rapid cycling bipolar disorder
• History of central nervous system illness or insult other than conditions associated with psychotropic exposure (e.g., tardive dyskinesia)
• Alcohol or substance abuse or dependence in the past year (DSM-V)
• Secondary diagnosis of a delirium, dementia, or amnestic disorder (DSM-V), pregnancy, or epilepsy
• Requires especially rapid antidepressant response due to suicidality, psychosis, inanition, psychosocial obligations, etc.
• No anticonvulsant mood stabilizers (e.g., Depakote, Tegretol, Lamictal); No lithium; No psychostimulants (e.g., Ritalin, Adderall);

Allowed medications during FEAST/ECT:

Antidepressants, including buproprion Atypical antipsychotics; Hypnotics for sleep; Anxiolytics (limited to up to 3 mg equivalents/day lorazepam)

• ECT in the past six months

The participants in baseline analysis were those that maintained inclusion criteria throughout the duration of the study. 2 participants were not counted in the baseline analysis population due to exclusionary circumstances.

Adverse events have been collected throughout the duration of the study, from the beginning of the treatments through the 6 month follow up.