Brain network localization of delusions

Delusions constitute a cross-diagnostic core symptom of schizophrenia spectrum disorders and correlate with poor functional outcomes. Despite much recent effort successfully mapping neuropsychiatric symptoms to specific brain networks, investigations focusing on network localization of delusions are still scarce.

We initially conducted a systematic review of 44 published neuroimaging studies to identify brain regions exhibiting structural and functional alterations associated with delusions. By applying functional connectivity network mapping to normative functional connectomes derived from two independent resting-state fMRI datasets, we mapped these affected brain regions to three delusion networks.

The delusion morphology and task-induced activation abnormality networks were both broadly distributed and had some spatial similarities. In addition to their shared spatial overlap with the ventral attention and somatomotor networks, the delusion morphology abnormality network showed greater spatial overlap with the frontoparietal and dorsal attention networks, while the task-induced activation abnormality network overlapped more extensively with the subcortical and limbic networks. Concurrently, the delusion resting-state activity abnormality network showed the greatest spatial overlap with the default network. In addition, the right opercular part of the inferior frontal gyrus, the right anterior agranular insula complex, and the right anterior portion of the superior temporal gyrus exhibited functional connectivity profiles with the highest spatial similarity to these delusion network probability maps and were therefore considered potential neuromodulation targets.

Aside from elucidating the neurobiological mechanism underlying delusions from a network perspective, our findings potentially inform the development of reliable biomarkers and targeted treatments for delusions.