Existing studies have shown that gray matter changes may be involved in the pathophysiology of major depression disorder (MDD). However, whether the severity of the disease can affect the change of gray matter was still controversial. The aim of the present study is to identify the changes of gray matter on patients with currently depressed MDD (cMDD) using metaanalysis based on the reported studies with VBM.
A systematic retrieval of PubMed, Web of Science, Embase, Medline, and Science Direct was conducted to identify VBM studies that compared the gray matter differences between MDD patients (untreated or not recovered) and healthy controls. A meta-analysis was then carried out to quantitatively evaluate the gray matter changes of patients with cMDD.
Seventeen data sets from 14 studies were used in the present meta-analysis. The results showed reduced gray matter in the left superior temporal gyrus, right superior temporal gyrus, right insula, left median network, and left inferior parietal gyrus in patients with cMDD. It was also shown that the percentage of female patients and the mean age did not have a significant relationship with gray matter changes.
The meta-analysis in the present study showed that the gray matter reduction not only exists in the frontal lobe and the hippocampus of patients with cMDD as reported in previous studies, but also exists in the temporal lobe, which may also be important in the pathophysiology basis of MDD.