1. The objective of this study was to compare the relative regional cerebral blood flow (rCBF) patterns of a group of adolescents with major depressive disorder (MDD) to a group of normal controls. 2. Seven adolescent patients with symptomatic MDD and 7 age- and gender-matched normal controls, underwent SPECT imaging with 99mTc-HMPAO while unmedicated and in a resting state. These subject's data were normalized to whole brain counts, oriented in Talairach space, and analyzed using a voxel-based, t-image approach. 3. The authors found relative rCBF increases in the depressed group as compared to normals in the right mesial temporal cortex, the right superior-anterior temporal lobe, and the left infero-lateral temporal lobe. We found rCBF decreases in the depressed group as compared to normals in the left parietal lobe, the anterior thalamus and the right caudate. 4. Adolescents with MDD show rCBF abnormalities similar to those found in adult MDD rCBF studies. Further controlled studies with larger numbers of MDD subjects and normal age- and gender-matched controls are necessary before any definitive conclusions can be made from these findings.