CEREBRAL HYPOPERFUSION IN MEDICATION RESISTANT, DEPRESSED-PATIENTS ASSESSED BY TC99M HMPAO SPECT

Functional imaging studies generally show decreased cerebral metabolis m and perfusion in depressed patients relative to normal controls, alt hough the location of the deficits varies. We used Tc99m HMPAO SPECT t o compare cerebral blood flow in medication resistant, depressed patie nts and a normal control group. HMPAO uptake ratios (adjusted for age) were significantly lower in the depressed patients in the transaxial slices 4 cm and 6 cm above the orbitomeatal line (OML) on the left sid e. Examining individual regions of interest (corrected for age and mul tiple testing), we found significantly lower perfusion in the left sup erior temporal, right parietal and bilateral occipital regions in the patient group. These findings are in limited agreement with previous H MPAO SPECT studies. Methodological differences between studies, partic ularly variability in adjusting data for age, lead to a divergence in findings. Future research should seek to standardize protocols and dat a analysis in order to generate comparable results.