Orbitofrontal and Cingulate Thickness Asymmetry Associated with Depressive Symptom Dimensions

Area of Science:

• Neuroscience
• Psychiatry
• Neuroimaging

Background:

• Depression is linked to cortical thickness changes, but findings conflict on thinning vs. thickening and lateralization.
• Subthreshold depressive symptoms may also involve cortical alterations, yet this remains under-researched.

Purpose of the Study:

• To investigate the relationship between specific depressive symptom dimensions and cortical thickness asymmetry.
• To examine cingulate and orbitofrontal cortex asymmetry in relation to depression severity.

Main Methods:

• Fifty-four adults underwent 3-Tesla MRI and completed the Center for Epidemiologic Studies Depression Scale (CES-D).
• Cortical thickness was measured in cingulate and orbitofrontal regions, and asymmetry indices were calculated.
• General linear models analyzed associations between CES-D subscales (somatic symptoms, negative affect, anhedonia) and asymmetry, controlling for age and sex.

Main Results:

• Higher anhedonia scores correlated with right-sided orbitofrontal cortex thickness asymmetry.
• Elevated somatic symptom scores predicted greater left-sided posterior cingulate cortex thickness asymmetry.
• Orbitofrontal findings were specific to the medial region; most participants had subthreshold depression.

Conclusions:

• Cortical thickness asymmetries are present even with subthreshold depressive symptoms.
• Different depression symptom dimensions are associated with distinct patterns of brain asymmetry.
• Understanding these asymmetries is crucial for developing targeted depression treatments.