EEG Biomarker Study for Participants in the Neurolief "MOOD" Trial

EEG Biomarkers may be useful for understanding abnormal brain oscillations associated with Major Depressive Disorder (MDD) and other psychiatric disorders as well as the brain changes that occur when symptoms remit. This study will invite adults with MDD who enroll and are randomized in the Neurolief Sponsored "MOOD" study to undergo collection of EEG data at pre-treatment baseline, again after completing the 8-week blinded treatment phase, and, if eligible/appropriate, again after completing an 8-week open-label treatment phase. EEG will be recorded at rest and during a computer task. This EEG "add-on" study is observational in nature, as it will not manipulate the treatment assignment in the MOOD clinical trial or otherwise impact concurrently ongoing treatments for any condition. Researchers collecting and analyzing EEG data will be blinded to treatment assignment when participants are in the double-blinded treatment phase of the MOOD clinical trial. EEG data will be processed and analyzed to evaluate changes in frontal alpha oscillations associated with 8 weeks of active Relivion®DP stimulation.