A TC-99M HEXAMETHYLPROPYLENE AMINE OXIME BRAIN SINGLE-PHOTON EMISSIONTOMOGRAPHY STUDY IN ADOLESCENT PATIENTS WITH MAJOR DEPRESSIVE DISORDER

We have not encountered any brain single-photon emission tomography (S PET) study performed in adolescent depressed patients in the literatur e. Therefore, we used technetium-99m hexamethylpropylene amine oxime ( Tc-99m-HMPAO) brain SPET in adolescent patients with major depressive disorder (MDD) to examine the possible changes in cerebral perfusion a .nd the possible association between perfusion indices and clinical va riables. Fourteen adolescent out-patients (nine females, five males; m ean+/-SD age: 13.11+/-1.43 years; range: 11-15 years) fulfilling the D SM-IV criteria for MDD and 11 age-matched healthy control subjects (si x females, five males; mean+/-SD age: 13.80+/-1.60 years; range: 12-15 years) were included in the study, Tc-99-HMPAO brain SPET was perform ed twice in the patient group and once in the control group. The first SPET investigation was per formed under non-medicated conditions and the second was performed after depressive symptoms had subsided. A rel ative perfusion index (PI) was calculated as the ratio of regional cor tical activity to the whole brain activity. We found significant diffe rences between the PI values of the untreated depressed patients and t hose of the controls, indicating relatively reduced perfusion in the l eft anterofrontal and left temporal cortical areas. No significant dif ferences in regional PI values were found between the remitted depress ed patients and the controls. Our study suggests that adolescent patie nts with MDD may have regional cerebral blood flow deficits in frontal regions and a greater anterofrontal right-left perfusion asymmetry co mpared with normal subjects. The fact that these abnormalities in perf usion indices have a trend toward normal values with symptomatic impro vement suggests that they may be state-dependent markers for adolescen t MDD.