FRONTAL AND PARIETAL METABOLIC DISTURBANCES IN UNIPOLAR DEPRESSION

The authors investigated brain glucose utilization using positron emis sion tomography (PET) in 12 normal volunteers and 12 unipolar unmedica ted depressed patients (six endogenous; six nonendogenous) following i njection of [18F]fluoro-deoxyglucose (FDG). Compared by analyses of va riance, absolute and relative regional glucose metabolic rates appeare d different in depressed patients and control subjects, especially in parietal and frontal lobes. In patients with unipolar depression, meta bolic rates were increased in the orbital part of the frontal lobe and decreased in a frontal dorsolateral area. The metabolic supero-basal gradient calculated in the frontal cortex was significantly lower in d epressed patients than in normal subjects. Decreased glucose metabolis m was also observed in the parietal cortex of depressed patients. No d ifferences in glucose metabolic rates have been detected between endog enous and nonendogenous patients. No correlation has been found betwee n the metabolic data and the Hamilton Rating Scale.