Ž . Psychiatry Research: Neuroimaging Section 98 2000 7191 Towards a neurobiology of dysfunctional arousal in depression: the relationship between beta EEG power and regional cerebral glucose metabolism during NREM sleep Eric A. Nofzinger a,  , Julie C. Price b , Carolyn C. Meltzer a,b , Daniel J. Buysse a , Victor L. Villemagne b , Jean M. Miewald a , Robert C. Sembrat b , Doris A. Steppe a , David J. Kupfer a a Department of Psychiatry, Western Psychiatric Institute and Clinic, 3811 O’Hara Street, Pittsburgh, PA 15213-2593, USA b Department of Radiology, Uni  ersity of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA Received 22 September 1999; received in revised form 12 January 2000; accepted 17 January 2000 Abstract This study sought to clarify the neurobiological basis of variations in one aspect of central nervous system ‘arousal’ Ž . in depression by characterizing the functional neuroanatomic correlates of beta electroencephalographic EEG Ž . Ž . power density during non-rapid eye movement NREM sleep. First, nine healthy n 9 subjects underwent  18  Ž 18  . Ž . concurrent EEG sleep studies and F 2-fluoro-2-deoxy-D-glucose F FDG positron emission tomography PET scans during their first NREM period of sleep in order to generate hypotheses about specific brain structures that show a relationship between increased beta power and increased relative glucose metabolism. Second, brain structures identified in the healthy subjects were then used as a priori regions of interest in similar analyses from identical studies in 12 depressed subjects. Statistical parametric mapping was used to identify the relationship Ž . between beta power and relative regional cerebral glucose metabolism rCMRglu during NREM sleep. Regions that demonstrated significant correlations between beta power and relative cerebral glucose metabolism in both the healthy and depressed subjects included the ventromedial prefrontal cortex and the right lateral inferior occipital cortex. During a baseline night of sleep, depressed patients demonstrated a trend toward greater beta power in relation to a separate age- and gender-matched healthy control group. In both healthy and depressed subjects, beta power negatively correlated with subjective sleep quality. Finally, in the depressed group, there was a trend for beta power to correlate with an indirect measure of absolute whole brain metabolism during NREM sleep. This study demonstrates a similar relationship between electrophysiological arousal and glucose metabolism in the ventromedial  Corresponding author. Tel.: 1-412-624-2246; fax: 1-412-624-2841. Ž . E-mail address: nofzingerea@msx.upmc.edu E.A. Nofzinger 0925-492700$ - see front matter  2000 Elsevier Science Ireland Ltd. All rights reserved. Ž . PII: S 0 9 2 5 - 4 9 2 7 00 00045-7