Abstract: The regional cerebral blood flow (rCBF) and the cerebral vasoreactivity of the patients with depressive disorder were observed by SPECT and acetazolamide stress SPECT test respectively. Eighteen unmedicated depressed patients and nineteen healthy control subjects were included. Baseline SPECT was performed in both patients and control subjects. Acetazolamide stress SPECT test was performed two days later in patients two hours after taking 2g acetazolamide orally. It was found that there was significant difference between the untreated depressed patients and the controls, because there was relatively reduced perfusion in frontal lobe, temporal lobe, left parietal lobe and right basal ganglia in depressed patients. After acetazolamide stress SPECT test, the perfusion of decreased regions in baseline step was increased. No potential ischemic lesion was found. The perfusion of some specific regions of the depressed patients decreased. Acetazolamide stress SPECT test could not reveal silent brain ischemia in the depressed patients. The perfusion of decreased regions in the baseline imaging was increased in acetazolamide stress SPECT test.Abstract: The regional cerebral blood flow (rCBF) and the cerebral vasoreactivity of the patients with depressive disorder were observed by SPECT and acetazolamide stress SPECT test respectively. Eighteen unmedicated depressed patients and nineteen healthy control subjects were included. Baseline SPECT was performed in both patients and control subjects. Ace...Show More