Brain function differences in drug-naïve first-episode auditory verbal hallucination-schizophrenia patients with versus without insight.

BACKGROUND: Few studies have reported brain function differences in drug-naïve first-episode schizophrenia patients who had auditory verbal hallucinations (AVH) with insight vs. those without insight. This study aimed to investigate brain function differences between drug-naïve first-episode AVH-schizophrenia patients with and without insight.

METHODS: Forty first-episode drug-naïve AVH-schizophrenia patients with or without insight and 40 healthy controls between December 2016 and December 2018 were recruited in this study. The auditory hallucinations rating scale (AHRS) was used to assess AVH severity, while the insight and treatment attitudes questionnaire was used to distinguish insight. The global functional connectivity density (gFCD) between different groups was compared using a voxel-wise one-way analysis of covariance. The relationship between gFCD and AHRS total scores were analyzed using voxel-wise multiple regression.

RESULTS: Finally, 13 first-episode drug-naïve AVH-schizophrenia patients with insight, 15 AVH-schizophrenia patients without insight, and 20 healthy controls were included for analysis. Except for global assessment of functioning scores, there were no significant differences in sociodemographic information between the AVH-schizophrenia and healthy groups (P > 0.05). Compared to the healthy controls, AVH-schizophrenia patients with insight demonstrated a decreased gFCD in the supra-marginal gyrus within the primary auditory cortex, while those without insight demonstrated an increased gFCD in the inferior frontal gyrus and superior temporal gyrus and decreased gFCD in the supplemental motor area. Compared to the AVH-schizophrenia patients with insight, those without insight demonstrated an increased gFCD in the supra-marginal gyrus and posterior superior temporal lobule and a decreased gFCD in the frontal lobe. No significant correlation between gFCD and AVH severity (AHRS total score: r = 0.23, P = 0.590; and frequency: r = 0.42, P = 0.820) was found in both AVH-schizophrenia groups.

CONCLUSIONS: The gFCD-aberrant brain regions in the AVH-schizophrenia patients without insight were wider compared to those with insight, although the AHRS scores were not significantly different. The AVH-schizophrenia patients without insight had wide functional impairment in the frontal lobule, which may underlie the lack of insight and the abnormal hyperactivity in the inferior frontal gurus and temporal lobe related to the AVH symptoms.