FUNCTIONAL CONNECTIVITY IN DEPRESSIVE, OBSESSIVE-COMPULSIVE, AND SCHIZOPHRENIC DISORDERS - AN EXPLORATIVE CORRELATIONAL ANALYSIS OF REGIONAL CEREBRAL METABOLISM

In order to investigate the changes in functional relationships betwee n brain regions in three psychiatric disorders, an exploratory statist ical analysis of the regional cerebral metabolic rates for glucose (rC MRglu) obtained with positron emission tomography (PET) was performed. Correlations between various rCMRglu were computed in control, depres sive, obsessive-compulsive, and schizophrenic groups to determine whet her alterations of the correlation pattern were found in the psychiatr ic groups. The absence of correlation between left and right frontal l obes was common to the three psychiatric groups studied. Depressive pa tients recovered a better frontal interhemispheric coupling after succ essful treatment and the alterations in the depressed state also invol ved the relation between the right temporal cortex and the right thala mus. Obsessive-compulsive patients had not only lateral frontal dysfun ction but also alterations in the functional relationships between cor tex and thalami. In schizophrenic patients, the modifications of regio nal cerebral metabolic correlations involved both anterior and posteri or cortical regions. Thus, although the relationship between left and right frontal lobes was altered in three psychiatric disorders, the pa ttern of functional connectivity between frontal regions, posterior co rtical and subcortical regions differed depending on the diagnostic gr oup. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.