Individuals with clinical high risk for psychosis (CHR) appear to have insular functional dysconnectivity with the sensory cortex and putamen, which is similar to that observed in patients with schizophrenia. A study on the topic was conducted among individuals from Beijing, China, with CHR; patients with first-episode schizophrenia; and healthy control individuals. Results of the analysis were published in Psychiatry Research.
Recognizing that abnormalities in insular functional connectivity have been linked to numerous clinical features of schizophrenia, the investigators sought to establish to what degree such abnormalities occur in individuals with CHR and whether they are associated with symptom severity. They obtained resting-state functional magnetic resonance imaging data from 24 individuals with CHR, 19 patients with first-episode schizophrenia, and 47 healthy control individuals. They used the posterior, dorsal, and ventral subregions as separate seeds to examine the resting-state functional connectivity differences among various groups and the relationship between concurrent symptom severity and dysconnectivity.
When compared with healthy control individuals, both individuals with CHR and patients with schizophrenia demonstrated hypoconnectivity between posterior insula and somatosensory areas, as well as between dorsal anterior insula and putamen. Patients with schizophrenia also demonstrated dorsal anterior insula and ventral anterior insula hyperconnectivity with visual areas relative to both individuals with CHR and control individuals.
According to correlation analysis, dorsal anterior insula functional connectivity with superior temporal gyrus was positively associated with positive symptoms of CHR. In addition, ventral anterior insula connectivity with dorsolateral prefrontal cortex was negatively correlated with the severity of the symptoms in patients with first-episode schizophrenia.
A major shortcoming of the study involved its small sample size, which limited the generalizability of the study findings. Moreover, similar to most studies that involve connectivity, head movements that occurred during the acquisition of imaging data were a concern.
The investigators concluded that the results from the current study imply that insular functional dysconnectivity within the sensory cortex may be a system-level neural substrate that precedes the onset of psychosis. Specific insular connectivity was shown to be associated with the severity of psychotic symptoms among the individuals who were evaluated.
Li X-B, Wang L-B, Xiong Y-B, et al. Altered resting-state functional connectivity of the insula in individuals with clinical high-risk and patients with first-episode schizophrenia. Psychiatry Res. 2019;282:112608.