A case-control study on QEEG as a marker of cognition in depression.

Background: Quantitative electroencephalography (QEEG) has emerged as an inexpensive electrophysiological testing modality versus other neuroimaging techniques such as functional magnetic resonance imaging for the identification of early cognitive changes related to electrical abnormalities and network dysfunctions. QEEG and cognitive measures have been extensively used in understanding physiological changes in the brain occurring in individuals with certain illnesses; however, studies ascertaining the relationship between QEEG and cognitive functions are scarce. Aim: To explore the relationship between QEEG and the cognitive status of patients with depression. Methods: The case group included individuals diagnosed with depressive disorder (MINI 7.0.2), whereas the control group comprised subjects without psychiatric illnesses (12-Item General Health Questionnaire, score ≤2). Cognition was assessed using ACE III (Hindi), and electroencephalograms were recorded in an alert, awake state in individuals in both case and control groups. Results: Forty-five age- and gender-matched (age ± 2 years, males = 29) subjects with depression (mean ± SD = 61.13 ± 10.634) and controls (mean ± SD = 60.51 ± 10.78) were recruited. In the case group, significant associations were seen in areas F3 theta with memory; F4 alpha with attention, memory, language, and visuospatial domains; and P4 delta with language and visuospatial domains. Conclusion: The activity of theta, alpha, and delta waves was significantly different between groups, suggesting their role in cognition.