FUNCTIONAL NEUROIMAGING STUDIES OF DEPRESSION - THE ANATOMY OF MELANCHOLIA

Functional brain imaging techniques, which permit noninvasive measures of neurophysiology and neuroreceptor binding, are powerful and sensit ive tools for research aimed at elucidating the pathophysiology of maj or depression. The application of these technologies in depression res earch has produced several studies of resting cerebral blood flow (BF) and glucose metabolism in subjects imaged during various phases of il lness and treatment. This review examines these data and the principle s relevant to their interpretation and discusses the insights they pro vide into the anatomical correlates of depression. Within the anatomic al networks implicated in emotional processing by other types of evide nce, these BF and metabolic data demonstrate that major depression is associated with reversible, mood state-dependent, neurophysiological a bnormalities in some structures and irreversible, trait-like abnormali ties in other structures. In some of the regions in which trait-like a bnormalities appear, abnormal metabolic activity appears at least part ly related to the anatomical abnormalities identified in magnetic reso nance imaging (MRI) studies of depression.