NEUROPSYCHOLOGICAL DYSFUNCTION IN DEPRESSION - THE RELATIONSHIP TO REGIONAL CEREBRAL BLOOD-FLOW

The relationship between neuropsychological test performance and regio nal cerebral blood flow (rCBF) was examined in 29 patients meeting Res earch Diagnostic Criteria (RDC) for major depression. Following a comp rehensive neuropsychological assessment two subsets of tests, comprisi ng tests that discriminated between patients and controls or between p atients with varying degrees of global cognitive impairment, were sele cted. These subtests were entered into a principal components analysis (PCA) which generated a two-factor solution, accounting for 50% of th e overall variance in. test scores. Individual patient loadings on eac h of these factors were subsequently correlated with regional cerebral blood flow (rCBF), as measured by positron emission tomography (PET). Both factors demonstrated significant correlations with rCBF in the m edial prefrontal cortex and frontal polar cortex while for each factor there were also unique patterns of correlations with posterior brain regions. The findings provide additional evidence that neuropsychologi cal deficits in depression are associated with abnormalities in region al brain function and in particular with the function of the medial pr efrontal cortex.