BACKGROUND: Depression is one of the most important factors affecting quality of life in Parkinson’s patients. Most research on Parkinson’s disease with depression has focused on neuroimaging, and there have been few quantitative electroencephalogram studies. Sleep is a biomarker for depression; therefore, the aim of this study was to identify differences in quantitative electroencephalograms during sleep in depressed and non-depressed patients with Parkinson’s disease.

MATERIAL AND METHODS: We assessed 38 Parkinson’s disease patients (26 depressed patients, 12 non-depressed patients) and 20 normal subjects using the Geriatric Depressive Scale for Depressive Symptoms and quantitative electroencephalogram analysis of amplitude of different frequency bands in different sleep stages using Met-lab software and Fast Fourier Transformation.

RESULTS: Non-rapid eye moment 2 and the Frontal 4 Electrode amplitude in the delta and theta ranges were progressively and significantly greater in the depressed-Parkinson’s disease group (p<0.05) than in the control group. In the depressed Parkinson’s disease group, from the comparison of non-rapid eye moment 2 and rapid eye moment, in Frontal 4 the amplitude in the delta ranges of non-rapid eye moment 2 was greater than in the non-depressed group, and in Central 3, Central 4, Occipital 1, and Occipital 2, the amplitudes in the beta ranges of rapid eye moment were greater (p<0.05) than in the non-depressed group.

CONCLUSIONS: The higher amplitude in theta in frontal areas in NREM2 and the higher amplitude in beta in parietal and occipital lobe areas in REM relative to NREM2 were significantly different in depressed and non-depressed patients with Parkinson’s disease.

Keywords: Depression, Electroencephalography, Parkinsonian Disorders, Sleep, Case-Control Studies, Depressive Disorder, Quality of Life, Sleep Stages, Wakefulness