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Assessment of glymphatic function in treatment-resistant depression using DTI-ALPS index
Xin Zhang1, Shaoyong Ye2, Maoxin Zhang1
1Department of Radiology, The Second Affiliated Hospital of Shandong First Medical University, Tai' an, 271000, China; School of Radiology, Shandong First Medical University & Shandong Academy of Medical Sciences, Tai' an, 271016, China.
Treatment-resistant depression (TRD) shows altered glymphatic function, indicated by elevated diffusion tensor imaging analysis along the perivascular space (DTI-ALPS) indices. This elevation may reflect perivascular space narrowing, not improved clearance, and correlates with clinical symptoms.
Area of Science:
- Neuroscience
- Radiology
- Psychiatry
Background:
- Treatment-resistant depression (TRD) pathophysiology is poorly understood.
- Glymphatic system dysfunction is a potential contributor to depression.
- Gaps exist in understanding glymphatic differences between TRD and non-TRD (nTRD) and their clinical correlations.
Purpose of the Study:
- To investigate glymphatic system function differences in TRD versus nTRD patients and healthy controls (HCs).
- To explore the association between glymphatic function markers and clinical symptoms in TRD and nTRD.
Main Methods:
- Diffusion tensor imaging analysis along the perivascular space (DTI-ALPS) was used to assess glymphatic function.
- 65 TRD patients, 110 nTRD patients, and 84 HCs were included.
- Partial correlation analyses examined relationships between DTI-ALPS index, Dyyproj, and clinical measures (e.g., HAMD).
Main Results:
- TRD patients showed elevated left-side and mean DTI-ALPS indices compared to nTRD and HCs.
- TRD patients had reduced left diffusivity of projection fibers along the y-axis direction (Dyyproj).
- In TRD, higher DTI-ALPS correlated with sleep disturbance; lower Dyyproj correlated with less anxiety/cognitive impairment. In nTRD, lower DTI-ALPS correlated with childhood trauma and milder anhedonia.
Conclusions:
- Elevated DTI-ALPS in TRD, linked to reduced Dyyproj, correlates with clinical features.
- This elevation likely indicates perivascular space narrowing rather than enhanced glymphatic clearance.
- Findings suggest glymphatic system alterations are implicated in TRD pathogenesis and symptom presentation.
