Connectivity alterations of mesostriatal pathways in first episode psychosis

Abstract

Background and hypothesis Pathogenic understanding of the psychotic disorders converges on regulation of dopaminergic signaling in mesostriatocortical pathways. Functional connectivity of the mesostriatal pathways may inform us of the neuronal networks involved. Study design This longitudinal study of first episode psychosis (FEP) (49 patients, 43 controls) employed seed-based functional connectivity analyses of fMRI data collected during a naturalistic movie stimulus. Study results We identified hypoconnectivity of the dorsal striatum with the midbrain, associated with antipsychotic medication dose in FEP, in comparison with the healthy control group. The midbrain regions that showed hypoconnectivity with the dorsal striatum also showed hypoconnectivity with cerebellar regions suggested to be involved in regulation of the mesostriatocortical dopaminergic pathways. None of the baseline hypoconnectivity detected was seen at follow-up. Conclusions These findings extend earlier resting state findings on mesostriatal connectivity in psychotic disorders and highlight the potential for cerebellar regulation of the mesostriatocortical pathways as a target of treatment trials.

Acute Psychotic Episode Precipitated by Opioid Withdrawal in a Case of Bipolar I Disorder

“…According to recent findings, the dorsal (associative) striatum is the region where dopaminergic dysfunction is most frequently observed. As dopaminergic activity associated with enhanced dopamine synthesis and release in psychotic illnesses originates in the midbrain, the midbrain connection is of particular relevance [ 8 ].…”