Positron emission tomography imaging in depression: a neural systems perspective.

PET measures of regional glucose metabolism, although chemically nonspecific, are sensitive indices of brain function in the untreated state and following disparate treatments. The continued development of imaging and multivariate statistical strategies is expected to provide an important perspective toward the full characterization of the depression phenotype at the neural systems level. An additional goal is the development of routine, brain-based clinical algorithms that optimize diagnosis and treatment of individual depressed patients.