Depression is a common psychiatric disorder affecting many people globally, and the worst outcome is suicide. But its neurobiology is hardly understood.

To use DTI to characterize abnormalities of white matter (WM) integrity in major depressive disorder patients with suicide attempts or suicidal ideation.

Present study aimed to give a more complete profile for the association of cerebral WM abnormalities with suicidal behavior in major depressive disorder patients by quantifying the suicidal ideation and behavior severity.

Thirteen depressive patients with suicide attempts (SA), 14 depressive patients with suicidal ideation but no suicide attempts (SI), 13 depressive patients without suicidal ideation or suicide attempts (NSD) and 40 healthy controls (HC) received MRI scans on a 3T magnet. Whole brain voxel-based analysis of FA based on DTI was performed among the four groups using a threshold of P<0.05 with FWE correction. FA values were extracted by Marsbar software to quantify the changes.

The four groups had significant differences of FA in the in the left splenium of corpus callosum (peak Z=5.36 at −14, −36, 22). Quantify comparison revealed that SA had significant decreased FA value than SI, NSD, and HC. There was no significant difference among the other three groups, although there was a trend that SI and NSD had lower FA values than HC in this region.

Depression and suicide are associated with microstructure abnormalities of the white matter and patients with suicide attempts may have severe cerebral alteration.