The Danish PET/depression project: clinical symptoms and cerebral blood flow. A regions-of-interest analysis

Objective: We wanted to explore associations between clinical symptoms of depression and the blood flow to specific regions of the brain. Furthermore, we wanted to compare the regions-of-interest (ROI) method with the functions-of-interest (FOI) approach. Method: The resting blood flow to 42 ROI in the brain was obtained with positron emission tomography (PET) imaging in 42 representative in-patients with major depression and 47 matched healthy controls. Results: The patients had increased blood flow to hippocampus, cerebellum, anterior cingulate gyrus, and the basal ganglia. A strong negative correlation was found between the degree of psychomotor retardation of the patients and the blood flow to the dorsolateral and supraorbital prefrontal cortices. The total Hamilton score was correlated with the blood flow to the hippocampus. Conclusion: Our findings support the notion that depressed patients have disturbances in the loops connecting the frontal lobes, limbic system, basal ganglia, and cerebellum.