Philadelphia, PA, July 30, 2015 - Depressed people often find themselves preoccupied with guilty, shameful, or self-defeating thoughts for large parts of their day. These thoughts not only distract from other activities but also fail to resolve the underlying life issues. Further, the ideas that receive focused attention in these depressive ruminations are frequently quite distorted and lead to distress.
The way that depressed people repetitively attend to these negative thoughts in an unproductive manner reflects the reasoning behind use of the term ruminations - because they call to mind the repetitive chewing of cud by ruminants like cows or goats.
The propensity for rumination in depression has been well characterized. However, a new study by Dr. J. Paul Hamilton at the Laureate Institute for Brain Research and his colleagues at Stanford University sheds light on the brain mechanisms giving rise to these symptoms.
Their work highlights the interplay of a brain region implicated in depression, the subgenual prefrontal cortex (sgPFC) and a brain network involved in reflection, sometimes called the default mode network (DMN). The DMN becomes activated when the brain's task-oriented circuits are not engaged, i.e., during times of self-referential thought.
By reanalyzing existing studies, Hamilton and colleagues show that depressive ruminations are more likely to emerge in depression when the firing of the sgPFC, signaling depressed mood, is more tightly coordinated with the firing of the DMN. They propose that the observed increased connectivity reflects a functional integration of sgPFC and DMN processes which, in turn, support rumination in depression.
"This study shows that depression distorts a natural process. It would seem that normally the subgenual prefrontal cortex helps to bias the reflective process supported by the default mode network so that we can consider important problems in the service of developing strategies for solving them," commented Dr. John Krystal, Editor of Biological Psychiatry.
"However, in depression it seems that the subgenual prefrontal cortex runs amok hijacking normal self-reflection in a maladaptive way. This may be one reason that electrical stimulation of the sgPFC is helpful for some patients with severe or treatment-resistant symptoms of depression."
###
The article is "Depressive Rumination, the Default-Mode Network, and the Dark Matter of Clinical Neuroscience" by J. Paul Hamilton, Madison Farmer, Phoebe Fogelman, and Ian H. Gotlib (doi: 10.1016/j.biopsych.2015.02.020). The article appears in Biological Psychiatry, Volume 78, Issue 4 (August 15, 2015), published by Elsevier.
http://www.sciencedirect.com/science/article/pii/S0006322315001432
Notes for editors
Full text of the article is available to credentialed journalists upon request; contact Rhiannon Bugno at +1 214 648 0880 or Biol.Psych@utsouthwestern.edu. Journalists wishing to interview the authors may contact J. Paul Hamilton at +1 650 387 7976 or paul.hamilton@laureateinstitute.org.
The authors' affiliations, and disclosures of financial and conflicts of interests are available in the article.
John H. Krystal, M.D., is Chairman of the Department of Psychiatry at the Yale University School of Medicine, Chief of Psychiatry at Yale-New Haven Hospital, and a research psychiatrist at the VA Connecticut Healthcare System. His disclosures of financial and conflicts of interests are available here.
About Biological Psychiatry
Biological Psychiatry is the official journal of the Society of Biological Psychiatry, whose purpose is to promote excellence in scientific research and education in fields that investigate the nature, causes, mechanisms and treatments of disorders of thought, emotion, or behavior. In accord with this mission, this peer-reviewed, rapid-publication, international journal publishes both basic and clinical contributions from all disciplines and research areas relevant to the pathophysiology and treatment of major psychiatric disorders.
The journal publishes novel results of original research which represent an important new lead or significant impact on the field, particularly those addressing genetic and environmental risk factors, neural circuitry and neurochemistry, and important new therapeutic approaches. Reviews and commentaries that focus on topics of current research and interest are also encouraged.
Biological Psychiatry is one of the most selective and highly cited journals in the field of psychiatric neuroscience. It is ranked 6th out of 140 Psychiatry titles and 10th out of 252 Neurosciences titles in the Journal Citations Reports® published by Thomson Reuters. The 2014 Impact Factor score for Biological Psychiatry is 10.255.
About Elsevier
Elsevier is a world-leading provider of information solutions that enhance the performance of science, health, and technology professionals, empowering them to make better decisions, deliver better care, and sometimes make groundbreaking discoveries that advance the boundaries of knowledge and human progress. Elsevier provides web-based, digital solutions -- among them ScienceDirect, Scopus, Elsevier Research Intelligence and ClinicalKey -- and publishes over 2,500 journals, including The Lancet and Cell, and more than 33,000 book titles, including a number of iconic reference works. Elsevier is part of RELX Group plc, a world-leading provider of information solutions for professional customers across industries. http://www.elsevier.com
Journal
Biological Psychiatry