University of Groningen Reduced Connectivity in the Self-Processing Network of Schizophrenia Patients with Poor Insight Liemburg,

Lack of insight (unawareness of illness) is a common and clinically relevant feature of schizophrenia. Reduced levels of selfreferential processing have been proposed as a mechanism underlying poor insight. The default mode network (DMN) has been implicated as a key node in the circuit for self-referential processing. We hypothesized that during resting state the DMN network would show decreased connectivity in schizophrenia patients with poor insight compared to patients with good insight. Patients with schizophrenia were recruited from mental health care centers in the north of the Netherlands and categorized in groups having good insight (n = 25) or poor insight (n = 19). All subjects underwent a resting state fMRI scan. A healthy control group (n = 30) was used as a reference. Functional connectivity of the anterior and posterior part of the DMN, identified using Independent Component Analysis, was compared between groups. Patients with poor insight showed lower connectivity of the ACC within the anterior DMN component and precuneus within the posterior DMN component compared to patients with good insight. Connectivity between the anterior and posterior part of the DMN was lower in patients than controls, and qualitatively different between the good and poor insight patient groups. As predicted, subjects with poor insight in psychosis showed decreased connectivity in DMN regions implicated in self-referential processing, although this concerned only part of the network. This finding is compatible with theories implying a role of reduced self-referential processing as a mechanism contributing to poor insight. Citation: Liemburg EJ, van der Meer L, Swart M, Curcic-Blake B, Bruggeman R, et al. (2012) Reduced Connectivity in the Self-Processing Network of Schizophrenia Patients with Poor Insight. PLoS ONE 7(8): e42707. doi:10.1371/journal.pone. 0042707 Editor: Yu-Feng Zang, Hangzhou Normal University, China Received March 2, 2012; Accepted July 11, 2012; Published August 9, 2012 Copyright: 2012 Liemburg et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Funding: This work was supported by the European Science Foundation European Young Investigators (EURYI) award (N.W.O. number 044035001) awarded to A.A. The website link: http://www.esf. org/activities/euryi.html. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing Interests: E.J. Liemburg, MSc reports no financial relationships with commercial interests. Dr. L. van der Meer reports no financial relationships with commercial interests. M. Swart, MSc reports no financial relationships with commercial interests. Dr. B. Curcic-Blake reports no financial relationships with commercial interests. Dr. R. Bruggeman reports no financial relationships with commercial interests. Dr. H. Knegtering is on the speakers list of Janssen-Cilag, BMS and Eli Lilly, and received unrestricted research grants from Eli Lilly, Astra Zeneca, Janssen-Cilag and BMS. These companies had no further role in the selection of literature and interpretation of data; in the writing of the review; and in the decision to submit the manuscript for publication. Dr. A. Aleman reports no financial relationships with commercial interests. Lentis Center for Mental Health Care is not a commercial organization, but a local public health care center without profitmaking activities. Being an employee of Lentis does not alter those authors’ adherence to all the PLoS ONE policies on sharing data and materials. The authors declare their adherence to all the PLoS ONE policies on sharing data and materials. * E-mail: E.J.Liemburg@umcg.nl