Structural connectivity and response to ketamine therapy in major depression: A preliminary study

Area of Science:

• Neuroimaging
• Neuroscience
• Psychiatry

Background:

• Ketamine rapidly reduces depressive symptoms in major depressive disorder (MDD).
• Predictors of ketamine response remain largely unknown.
• Diffusion imaging may reveal microstructural differences related to treatment outcomes.

Purpose of the Study:

• To investigate if white matter microstructure differences predict clinical response to ketamine in MDD patients.
• To compare diffusion imaging metrics between ketamine responders and non-responders.

Main Methods:

• Used Tract-Based Spatial Statistics (TBSS) to analyze diffusion imaging data.
• Examined fractional anisotropy (FA), radial diffusivity (RD), axial diffusivity (AD), and mean diffusivity (MD).
• Compared 10 MDD patients (responders vs. non-responders) with 15 controls.

Main Results:

• Responders had higher FA in the cingulum and forceps minor compared to non-responders.
• Non-responders showed decreased FA and increased RD/MD in specific white matter tracts compared to controls.
• Earlier onset and longer episodes were noted in non-responders but did not correlate with imaging findings.

Conclusions:

• Preliminary findings suggest white matter structural differences predict ketamine response in MDD.
• Altered microstructural integrity in fronto-limbic and ventral striatal pathways may indicate non-response.
• Further research with larger sample sizes is warranted.