The abnormality of brain functional connectivity networks in first-episode schizophrenia and association with psychological and physiological stress.

OBJECTIVE

Schizophrenia is characterized by significant disruptions in the function of brain network (e.g., default mode network (DMN), executive control network (ECN)). In this study, we investigated whether there was a relationship between psychological and physiological stress factors and the brain network abnormalities among individuals suffering from first-episode schizophrenia.

METHODS

Fifty-six participants with first-episode schizophrenia were recruited together with age- and sex-matched healthy controls (n = 90). Brain functional connectivity networks between two groups was compared using network-based statistics (NBS). We further examined whether functional connectivity (FC) was correlated to different indices for both psychological and physiological stresses in 23 patients.

RESULTS

The brain functional connectivity networks in the schizophrenia group were significantly stronger than those in the healthy group. The top three networks pairs providing edge contribution were DMN-DMN, DMN-frontoparietal control network (FPCN), and DMN-limbic network (LIM). We found that FC value was positively correlated with indexes of stress factor. The correlations between FC values and Health Risk Factors of Stress Assessment (HRSFA, r = 0.43, p = 0.039), Psychological Stress Coefficient (PsySC, r = 0.48, p = 0.022), and Psychological Stress Index (PsySI, r = 0.49, p = 0.018) scores were reported in our sample.

CONCLUSIONS

Our findings provided new insights about how schizophrenic's functional connectome operates and highlighted the importance of incorporating information on stress upon understanding such disorders. Importantly, brain-behavior correlations should be interpreted cautiously due to the small sample size. Further studies should examine changes of functional connectivity or stress level over time.