J Psychiatry Neurosci 2017;42(1):17-26
Pierre Orban, PhD; Martin Desseilles, MD, PhD; Adrianna Mendrek, PhD; Josiane Bourque, MSc; Pierre Bellec, PhD; Emmanuel Stip, MD
Background: Schizophrenia has been defined as a dysconnection syndrome characterized by aberrant functional brain connectivity. Using task-based fMRI, we assessed to what extent the nature of the cognitive context may further modulate abnormal functional brain connectivity.
Methods: We analyzed data matched for motion in patients with schizophrenia and healthy controls who performed 3 different tasks. Tasks 1 and 2 both involved emotional processing and only slighlty differed (incidental encoding v. memory recognition), whereas task 3 was a much different mental rotation task. We conducted a connectome-wide general linear model analysis aimed at identifying context-dependent and independent functional brain connectivity alterations in patients with schizophrenia.
Results: After matching for motion, we included 30 patients with schizophrenia and 30 healthy controls in our study. Abnormal connectivity in patients with schizophrenia followed similar patterns regardless of the degree of similarity between cognitive tasks. Decreased connectivity was most notable in the medial prefrontal cortex, the anterior and posterior cingulate, the temporal lobe, the lobule IX of the cerebellum and the premotor cortex.
Limitations: A more circumscribed yet significant context-dependent effect might be detected with larger sample sizes or cognitive domains other than emotional and visuomotor processing.
Conclusion: The context-independence of functional brain dysconnectivity in patients with schizophrenia provides a good justification for pooling data from multiple experiments in order to identify connectivity biomarkers of this mental illness.
Submitted July 13, 2015; Revised Nov. 19, 2015; Accepted Jan. 5, 2016; Early-released Apr. 19, 2016
Acknowledgements: This work was supported by grants from the Canadian Institutes of Health Research, Gender and Health Institute (grant number 200603MOP-158161-GSH-CFCA-130656 to A.M.), from the Natural Sciences and Engineering Research Council of Canada (grant number RN000028 to P.B.) and from investigator-initiated trials to E.S. (clinical trial number: NCT 00290121).
Affiliations: From the Department of Psychiatry, Université de Montréal, Montreal, Que., Canada (Orban); the Department of Psychology, Faculty of Medicine, University of Namur, Belgium (Desseilles); the Department of Psychology, Bishop’s University, Sherbrooke, Que., Canada (Mendrek); the Department of Psychiatry, Université de Montréal, Montreal, Que., Canada (Bourque); the Department of Computer Sciences and Operational Research, Université de Montréal, Montreal, Que., Canada (Bellec); and the Department of Psychiatry, Université de Montréal, Montreal, Que., Canada (Stip).
Competing interests: P. Bellec declares being a member of an advisory board for Roche and is currently a part-time consultant for two contract research organizations, Biospective Inc. and NeuroRX research. E. Stip is on the scientific advisory boards for Janssen, Otsuka, Lundbeck, Sunovion and BMS. He has also received grants or research support from Roche. No other competing interests declared.
Contributors: P. Orban, A. Mendrek and E. Stip designed the study. A. Mendrek and J. Bourque acquired the data, which P. Orban, J. Bourque and P. Bellec analyzed. P. Orban, M. Desseilles, P. Bellec and E. Stip wrote the article, which all authors reviewed and approved for publication.
Correspondence to: P. Orban, CRIUGM, Université de Montréal, 4545 Queen Mary, Montreal, QC H3W 1W5; email@example.com