Frontal dysfunction underlies depressive syndrome in Alzheimer disease: a FDG-PET study.

OBJECTIVE This study aimed to investigate the regional cerebral dysfunction associated with depressive syndrome in patients with Alzheimer disease (AD). METHOD Twelve patients with AD with depressive syndrome (ADD) and 12 age-, gender-, and severity-matched patients with AD without depressive syndrome (ADND) underwent FDG-PET scanning. The regional cerebral glucose metabolism in the two groups was compared using a voxel-based method. RESULTS The ADD group showed lower glucose metabolism in the right superior frontal gyrus than the ADND group. CONCLUSIONS These results indicate that frontal dysfunction, known to be associated with primary or other secondary depressive syndromes, underlies the depressive syndrome of patients with AD patients as well.