Volume enlargement of the choroid plexus and brain ventricles in drug-naïve, first-episode major depressive disorder.

Background: We investigated volumetric alterations in the bilateral choroid plexus (ChP) and brain ventricles of patients during their first episode of major depressive disorder (MDD) prior to antidepressant treatment.

Methods: Seventy-one first-episode drug-naïve patients with MDD and seventy-four healthy control (HC) subjects were recruited. MRI data were obtained, and bilateral ChP and brain ventricle volumes were evaluated using segmentation, based on the adaptive multiscale and expectation maximization method. One-way multivariate analysis of covariance was used to calculate volumetric differences in the bilateral ChP and brain ventricles between the groups, and partial Pearson correlation analyses were used to investigate the relationship between the volumes of the bilateral ChP and brain ventricles.

Results: First-episode drug-naïve patients with MDD showed enlarged volumes of the bilateral ChP, bilateral lateral ventricle (LV), and third ventricle compared with HCs. The ChP volume positively correlated with the LV and third ventricle, but not with the fourth ventricle in patients with MDD, whereas it correlated with all four brain ventricles in HCs. We did not observe significant correlations between bilateral ChP volume and brain ventricles, HAMD scores, or symptom severity.

Limitations: Our study populations differed in age and sex and we did not extensively measure the amount of neuroinflammation in the brain or blood, include a functional assessment, nor evaluate other neural comorbidities or neuropsychiatric conditions.

Conclusions: Our study extends the existing research to suggest that illness-related alterations in ChP volume enlargement in first-episode antidepressant-naïve patients with MDD may serve as a trait measure.