The involvement of the cerebellar vermis across the psychotic-affective spectrum in enriched samples of recent-onset schizophrenia, bipolar disorder, and major depressive disorder

Abstract

Background: The cerebellar vermis is implicated in cognition and emotion, two key components of the psychotic-affective spectrum that includes schizophrenia (SCZ), bipolar disorder (BD), and major depressive disorder (MDD).

Methods: Volumes [N = 391; 97 SCZ, 78 BD, 103 MDD, and 113 healthy controls (HC)] and seed-to-whole brain functional connectivity (FC) [N = 136; 33 SCZ, 23 BD, 51 MDD, and 29 HC] of total vermis and its subregions, V1 (anterior), V2 (posterior superior), and V3 (posterior inferior), were examined across SCZ, BD, MDD, and HC in samples enriched for first episode individuals. The relationship between vermis volumes and FC and cognitive measures were explored.

Results: Significant diagnosis (p = 0.05) and diagnosis by subregion (p = 0.02) effects on vermis volumes were observed across the four groups, particularly in V2 (p = 0.01) with decreased V2 volumes in SCZ compared to BD (p_FDR = 0.01). SCZ, BD, and MDD had significant effects on vermis FC, with SCZ having the greatest effects. SCZ had effects on FC of V1, V2, and V3 with broadly distributed cortical and subcortical regions, while BD and MDD effects were observed in FC of V2 and V3 with frontotemporal regions. Exploratory analyses found significant canonical correlation between V3 FC and WM and visual learning for SCZ and MDD. No significant associations were shown between vermis volumes and cognitive measures.

Conclusions: Structural and functional alterations of the vermis appear to vary across the psychotic-affective spectrum of SCZ, BD, and MDD. Posterior vermis may be a key neural intersection between affective and psychotic psychopathology.

Keywords: Bipolar disorder; Cerebellar vermis; Functional connectivity; Major depressive disorder; Schizophrenia; Volume.