The study entitled '99mTc-HMPAO SPECT Study of Cerebral Perfusion After Treatment With Medication and Electroconvulsive Therapy in Major Depression', was conducted by a team of researchers led by Omer Bonne at Hadassah-Hebrew University Medical Center in Jerusalem, Israel.
Earlier studies have shown that cerebral blood flow in depressed patients is lower than in healthy control subjects, especially in frontal, limbic and subcortical brain regions.
As part of the study to see whether improvement in clinical depression was accompanied by changes in cerebral blood flow, researchers examined 33 depressed patients and 25 healthy control subjects with SPECT (single photon emission computed tomography), a molecular imaging/nuclear medicine procedure and the radiotracer 99mTc-HMPAO.
SPECTA utilizes injected radiotracers to produce three-dimensional, computer-reconstructed images that reveal information about both structure and function.
The study found that antidepressant decreased brain blood flow in the patients while electroconvulsive treatment was associated with additional decreases in blood flow.
"We found that cerebral blood flow increased only in patients whose depression improved. In contrast, cerebral blood flow remained unchanged in patients whose depressed condition persisted," Bonne said.
"Currently, clinical psychiatry is based almost solely on subjective observer-based judgment. Our findings suggest that objective imaging evaluations could support subjective clinical decisions," he said.
The findings of the study were published in the August issue of Journal of Nuclear Medicine.