Optical coherence tomography in patients with major depressive disorder

Area of Science:

• Ophthalmology
• Neuroscience
• Psychiatry

Background:

• Optical coherence tomography (OCT) is a key non-invasive imaging tool for psychiatric research.
• While OCT shows promise for neurodegenerative diseases like Alzheimer's and Parkinson's, its findings in major depressive disorder (MDD) are inconsistent.
• Previous studies indicate functional retinal alterations in MDD via electroretinogram (ERG) responses.

Purpose of the Study:

• To investigate structural retinal changes, specifically retinal layer thinning, in patients with MDD.
• To determine if these structural changes correlate with the severity of depressive symptoms.

Main Methods:

• Optical coherence tomography (OCT) scans were performed on 31 MDD patients and 60 healthy controls (HC).
• Macular retinal layer thickness and volume were analyzed.
• Correlations between retinal structure and depressive symptom scores (BDI-II, MADRS) were assessed.

Main Results:

• Significant reduction in outer nuclear layer (ONL) thickness was observed in MDD patients compared to HC (p=0.003).
• ONL thickness negatively correlated with depressive symptom severity (BDI-II scores; p=0.001).
• Ganglion cell and inner plexiform layer thickness and volume were inversely associated with depressive symptoms (p<0.02).

Conclusions:

• ONL thinning in MDD suggests potential neurodegenerative processes impacting signal transmission.
• OCT-based structural retinal analysis may complement ERG findings in MDD.
• This approach shows promise for developing diagnostic and monitoring tools for MDD.