The relationship of regional cerebral blood flow with subtypes of major depression.

UNLABELLED: The aim of the present study was to search for differences between subtypes of major depression with the use of single photon emission tomography.
MATERIALS AND METHODS: Fifty (50) patients aged 21-60 years suffering from Major Depression according to DSM-IV took part in the study. The SCAN v 2.0 was used to assist clinical diagnosis. The psychometric assessment included the HDRS, the HAS, the GAF, the Newcastle scales and the Diagnostic Melancholia Scale (DMS). Single Photon Emission Computerized Tomography (HMPAO SPECT) was used to assess regional cerebral blood flow. The methods of analysis included chi-square test, ANCOVA, and Discriminant Function Analysis.
RESULTS: Forty one (82%) depressed patients had abnormal SPECT findings. The most consistent finding in all patients across all subtypes was a global brain hypoperfusion, which did not include the frontal lobes. The most impressive finding was the relative increase of right frontal lobe perfusion in atypicals, in contrast to the relative decrease of perfusion in both the melancholic and the 'undifferentiated' patients in that particular region. The reverse was true for the right occipital lobe.
CONCLUSION: The results of the current study provide support for the old hypothesis on the existence of two distinct types of depression, characterized by different underlying psychopathologies, but also provide strong evidence for a neurobiological abnormality underlying atypical depression, the subtype closer to the old concept of 'neurotic' depression, which was considered to be psychological or reactive in origin.