# Depression Severity, Slow- versus Fast-Wave Neural Activity, and Symptoms of Melancholia

## TL;DR

This study explores how brain wave patterns in depressed and non-depressed individuals relate to symptoms of melancholia.

## Contribution

The study identifies distinct correlations between specific brain wave ratios and melancholic symptoms in depressed individuals.

## Key findings

- Depressed participants showed direct correlations between brain wave ratios and feelings of being a burden.
- Non-depressed participants had inverse correlations between theta/beta activity and symptoms like feeling useless.
- The parietal–occipital region's fast- and slow-wave activity is linked to cognitive aspects of melancholia.

## Abstract

Melancholia is a major and severe subtype of depression, with only limited data regarding its association with neurological phenomena. To extend the current understanding of how particular aspects of melancholia are correlated with brain activity, electroencephalographic data were collected from 100 adults (44 males and 56 females, all aged 18 y or more) and investigated for the association between symptoms of melancholia and the ratios of alpha/beta activity and theta/beta activity at parietal–occipital EEG sites PO1 and PO2. The results indicate differences in these associations according to the depressive status of participants and the particular symptom of melancholia. Depressed participants exhibited meaningfully direct correlations between alpha/beta and theta/beta activity and the feeling that “Others would be better off if I was dead” at PO1, whereas non-depressed participants had significant inverse correlations between theta/beta activity and “Feeling useless and not needed” and “I find it hard to make decisions” at PO1. The results are discussed in terms of the relative levels of fast-wave (beta) versus slow-wave (alpha, theta) activity exhibited by depressed and non-depressed participants in the parietal–occipital region and the cognitive activities that are relevant to that region.