title: Relationship between regional brain metabolism, illness severity and age in depressed subjects.
abstract: We sought to examine the effects of age, depression chronicity, and treatment responsiveness on glucose metabolism in a large well-characterized sample of depressed men and a psychiatrically unaffected control group. The subjects were unmedicated, symptomatic, right-handed males (n=66) who met DSM-IV criteria for a major depressive episode in the context of a major depressive disorder (MDD, n=66) and never depressed, right-handed, healthy control subjects (HC, n=24). Subjects in the MDD group were subsequently classified as responders, or non-responders to a six-week trial of paroxetine monotherapy (20-60 mg). Statistical parametric mapping (SPM) was used to analyze the relationship between age and cerebral glucose metabolism (18-fluorodeoxyglucose positron emission tomography) and the modulation by treatment responsivity and a history of prior depressive episodes. Metabolic activity in the rostral and dorsal anterior cingulate cortex showed a significant negative correlation with age in MDD, but not in HC. Non-response to treatment and previous depressive episodes were associated with a higher degree of age-dependent hypometabolism in the rostral and anterior cingulate cortex. The age-dependent changes documented herein may influence the distinct clinical presentation and treatment response described in older-age depression.
authors.affiliation: Institute of Medical Science, University of Toronto, Toronto, ON, Canada.
authors.forename: Jakub Z
authors.initials: JZ
authors.lastname: Konarski
authors.forename: Sidney H
authors.initials: SH
authors.lastname: Kennedy
authors.forename: Roger S
authors.initials: RS
authors.lastname: McIntyre
authors.forename: Shahryar
authors.initials: S
authors.lastname: Rafi-Tari
authors.forename: Joanna K
authors.initials: JK
authors.lastname: Soczynska
authors.forename: Helen S
authors.initials: HS
authors.lastname: Mayberg
mesh_terms: D000328:Adult; D000367:Age Factors; D001921:Brain / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000503:physiopathology*; D003865:Major Depressive Disorder / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000503:physiopathology*; D005947:Glucose / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography; D012720:Severity of Illness Index
chemical_list: D005947:Glucose