J Psychiatry Neurosci 2016;41(5):295-303
Wolfram Regen, MD; Simon D. Kyle, PhD; Christoph Nissen, MD; Bernd Feige, PhD; Chiara Baglioni, PhD; Jürgen Hennig, PhD; Dieter Riemann, PhD; Kai Spiegelhalder, PhD
Background: Psychological models highlight the bidirectional role of self-referential processing, introspection, worry and rumination in the development and maintenance of insomnia; however, little is known about the underlying neural substrates. Default mode network (DMN) functional connectivity has been previously linked to these cognitive processes.
Methods: We used fMRI to investigate waking DMN functional connectivity in a well-characterized sample of patients with primary insomnia (PI) and good sleeper controls.
Results: We included 20 patients with PI (8 men and 12 women, mean age 42.7 ± 13.4 yr) and 20 controls (8 men and 12 women, mean age 44.1 ± 10.6 yr) in our study. While no between-group differences in waking DMN connectivity were observed, exploratory analyses across all participants suggested that greater waking connectivity between the retrosplenial cortex/hippocampus and various nodes of the DMN was associated with lower sleep efficiency, lower amounts of rapid eye movement sleep and greater sleep-onset latency.
Limitations: Owing to the cross-sectional nature of the study, conclusions about causality cannot be drawn.
Conclusion: As sleep disturbances represent a transdiagnostic symptom that is characteristic of nearly all psychiatric disorders, our results may hold particular relevance to previous findings of increased DMN connectivity levels in patients with psychiatric disorders.
Submitted Oct. 6, 2014; Revised June 1, 2015; Accepted Sept. 1, 2015; Early-released Jan. 26, 2016
Affiliations: From the Department of Psychiatry and Psychotherapy, University of Freiburg Medical Centre, Freiburg, Germany (Regen, Nissen, Feige, Baglioni, Riemann, Spiegelhalder); the School of Psychological Sciences, University of Manchester, Manchester, UK (Kyle); and the Department of Diagnostic Radiology, University of Freiburg Medical Centre, Freiburg, Germany (Hennig).
Funding: This work was supported by the Else Kröner-Fresenius- Stiftung grant (grant number 2011_A208) awarded to D. Riemann and K. Spiegelhalder.
Competing interests: C. Nissen has received speaker honoraria from Servier. D. Riemann has received personal fees from Abbvie. No other competing interests declared.
Contributors: W. Regen, C. Nissen, D. Riemann and K. Spiegelhalder designed the study. W. Regen, C. Baglioni and K. Spiegelhalder acquired the data, which all authors analyzed. W. Regen, S. Kyle, J. Hennig and K. Spiegelhalder wrote the article, which all authors reviewed and approved for publication.
Correspondence to: K. Spiegelhalder, University Medical Center Freiburg, Department of Psychiatry and Psychotherapy, Hauptstraße 5, 79104 Freiburg, Germany; kai.Spiegelhalder@uniklinik-freiburg.de