State-Like Changes in the Salience Network Correlate with Delusion Severity in First-Episode Psychosis Patients
Jonatan Panula, Jussi Alho, Maija Lindgren, Tuula Kieseppä, Jaana Suvisaari, Tuukka Raij
Study at a glance
AI-extracted from the abstract| Characteristics | Observational cohort |
|---|---|
| Sample size | 51 |
| Population | First-episode psychosis patients and control subjects |
| Duration | One-year follow-up |
| Key findings | Delusion severity negatively correlated with intra-subject correlation in the bilateral anterior insula and anterior cingulate, and functional connectivity between the salience network and precuneus was lower in patients at baseline than in controls and remitted patients. |
Abstract
Background and hypothesis: Delusions are characteristic of psychotic disorders; however, the brain correlates of delusions remain poorly known. Imaging studies on delusions typically compare images across individuals. Related confounding of inter-individual differences beyond delusions may be avoided by comparing delusional and non-delusional states within individuals.Study design: We studied correlations of delusions using intra-subject correlation (intra-SC) of functional magnetic resonance imaging (fMRI) signal-time series, time-locked to movie stimulus, in 24 first-episode psychosis patients and 27 control subjects. We calculated intra-SC between fMRI signals obtained during psychotic symptoms and a one-year follow-up study when all patients were free of delusions. In addition, we studied changes in functional connectivity at baseline and during the one-year follow-up using regions where delusion severity correlated with intra-SC as seeds.Results: The intra-SC negatively correlated with the baseline delusion severity in the bilateral anterior insula and the anterior cingulate, corresponding to the cortical salience network (SN). Functional connectivity between the SN and the precuneus was lower in the patients at baseline than in control subjects and the patients at remission.Conclusions: The results suggest that intra-SC is a powerful tool to study brain correlates of symptoms, and highlight the role of the SN and internetwork dysconnectivity between the SN and the default mode network in delusions.Funding Information: This work was supported by the Sigrid Jusélius Foundation (J.S.), the Finnish Cultural Foundation (J.S.), the Medical Society of Finland (J.M.P.), the Academy of Finland (grants #278171 and #323035 to J.S. and #315861 to T.T.R.), the Finnish Medical Foundation (J.M.P. and T.T.R.), state funding for university-level health research (Hospital District of Helsinki and Uusimaa #TYH2013332, #TYH2014228, #TYH2017128 to T.K.), and the European Union's Seventh Framework Programme for project METSY (# 602478 to J.S.).Declaration of Interests: The Authors have declared that there are no conflicts of interest in relation to the subject of this study. Ethical Approval Statement: The initial evaluation was performed after initiation of treatment and after receiving written consent from the participants. The study was approved by the Ethics Committee of the University Hospital District of Helsinki and Uusimaa.