An exploration of the association between sub bands of gamma and individual symptoms of melancholia

Melancholia is often found to be unresponsive to standard antidepression medication. In the search for biomarkers that may also suggest possible treatment options, some attention has been given to EEG data. However, this research has largely ignored the gamma band of electrical activity in the brain (30-130 Hz). In an exploratory investigation of the association between melancholia and gamma wave activity, a standardized 8-item scale was completed by 100 community participants, who also underwent eyes-open and eyes-closed EEG data collection from 30 brain sites. There was a significant association between severity of depression, melancholia, and gamma. Individual melancholia symptoms were found to have meaningful correlations with specific EEG sites, which were then further explored via source localization (eLORETA). Most associations between gamma and melancholia items as measured via eLORETA were direct, indicating that, as gamma increased, so did participants' severity of particular melancholia symptoms, implying that depressed participants utilized increased neurocognitive activity as a possible strategy for coping with aspects of melancholia. Although these results are exploratory, they address a gap in the literature and suggest several hypotheses for future research.