Systematic review of brain glucose metabolic studies in patients with depression

Abstract

Objective To explore brain glucose metabolism changes in positron emission tomography (PET) studies in depression patients with systematic review and meta-analysis. Methods Standard search strategy for the Cochrane Review Group was performed in PubMed, EMBase, and Web of Science, PsycINFO, Cochrane Library, CNKI, Wanfang, VIP and CBMDisc databases. The papers were published from Jan 1, 1982 to Apr 8, 2014. Search key words included depression, depressive, PET, position emission tomography, FDG and 18F-Fluorodeoxyglucose. Hand searching and truncation were also used to avoid missing references. Psychiatric journals and fluoro-deoxyglucose related articles were manual searched from 2013 October to April 2014. SDM (signed differential mapping) software was used for voxel-based meta-analysis (P≤0.005, extent threshold>10). MNI coordinates were calculated to Talairach coordinates in all of the included studies. Brain parameter mapping was reconstructed by SDM software. Then Pooled Meta-analysis was performed. Results Ten studies met the inclusion criteria, including 188 depressed patients and 169 healthy controls. There was no significant heterogeneity between the ten studies (P> 0.05). SDM analysis showed depressive patients had decreased brain metabolism in right inferior frontal gyrus (orbital part and opercular part), right gyrus rectus, right dorsolateral superior frontal gyrus, right median cingulate/paracingulate gyri, left superior temporal gyrus and left middle frontal gyrus (orbital part) and increased brain metabolism in bilateral thalamus, right angular gyrus and left precentral gyrus. Conclusions These results suggest that depressive patients had brain function abnormalities with decreased activity in fronto-temporal-limbic system and increased activity in thalamus. Key words: Depression; Positron emission tomography; Meta analysis