Abstract
A longer duration of untreated psychosis (DUP) has been associated with poor clinical outcomes in patients with schizophrenia (SZ); however, it remains unclear whether this is due to neurotoxic effects of psychosis. The purpose of this study was to use near-infrared spectroscopy (NIRS) to investigate the influence of DUP on brain function using two verbal fluency tests (VFTs) in patients with first-episode SZ (FES). A total of 28 FES patients and 29 healthy controls (HC) underwent NIRS during VFTs. Group comparisons of cortical activity were made using two-tailed t-tests and the false discovery rate method. We then examined the associations between DUP and hemodynamic changes in each channel to identify any effects of DUP on brain cortical activity. During the letter VFT, the HC group exhibited significantly greater cortical activations over bilateral frontotemporal regions compared to FES patients. However, this distinction was not observed while performing a category version of the VFT. In addition, no associations between DUP and brain cortical activity were observed in the FES group during either VFT. In conclusion, we did not find an association between DUP and frontotemporal cortical activities. This might be because neurodevelopmental disturbances result in neurocognitive deficits long before psychotic symptoms onset.
Highlights
In the past two decades, many studies have investigated the effects of duration of untreated psychosis (DUP) on the brain, but they have yielded conflicting results
(1) There were significant increases in both groups’ cortical activities over bilateral frontotemporal regions during both verbal fluency tests (VFTs). (2) There was a difference in the cortical activity patterns between the 2 groups during the letter fluency task (LFT) but not the category fluency task (CFT), indicating that deficits in cortical activity during phonemic processing may occur early in the course of SZ. (3) There was a lack of association between DUP and cortical activities during both VFTs
We found significantly increased cortical activities in the healthy controls (HC) group during both types of VFT over bilateral frontotemporal regions, which is consistent with several previous near-infrared spectroscopy (NIRS) studies[32,33,34,35,36]
Summary
In the past two decades, many studies have investigated the effects of DUP on the brain, but they have yielded conflicting results. Some studies demonstrated that longer DUP had negative effects on brain morphological changes[13,14,15,16,17], but others did not[18,19,20,21,22,23]. A critical review by Rund et al concluded that there was limited evidence for a relationship between DUP and changes in neurocognitive functions or brain structures[24]. Anderson et al.’s review listed minimal evidence of an association between untreated psychosis and brain structure[25]. These neuroimaging and neuropsychological findings may raise the question ‘Is. S. Active psychosis neurotoxic?’ In 2006, McGlashan argued that if active psychosis was neurotoxic, certain manifestations would be expected in the course of the illness, but there is little evidence for such a process[26]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
