Carew CL, Milne AM, Tatham EL, Macqueen GM, Hall GB. Behav. Brain Res. 2013; 257: 13-24.
Affiliation
Department of Psychiatry and Behavioural Neurosciences, McMaster University Room F130, Fontbonne Building 50 Charlton Ave. E. Hamilton, Ontario, Canada L8N 4A6; McMaster Integrative Neuroscience Discovery and Study, McMaster University 1280 Main Street West Hamilton, ON L8S 4K1.
OBJECTIVE: Ruminative brooding is associated with increased vulnerability to major depression. Individuals who regularly ruminate will often try to reduce the frequency of their negative thoughts by actively suppressing them. We aimed to identify the neural correlates underlying thought suppression in at-risk and depressed individuals.
METHODS: Three groups of women were studied; a major depressive disorder group, an at-risk group (having a first degree relative with depression) and controls. Participants performed a mixed block-event fMRI paradigm involving thought suppression, free thought and motor control periods. Participants identified the re-emergence of "to-be-suppressed" thoughts with a button press.
RESULTS: During thought suppression the control group showed the greatest activation of the dorsolateral prefrontal cortex, followed by the at-risk, then depressed group. During the re-emergence of intrusive thoughts compared to successful re-suppression of those thoughts, the control group showed the greatest activation of the anterior cingulate cortices, followed by the at-risk, then depressed group.
CONCLUSIONS: At-risk participants displayed anomalies in the neural regulation of thought suppression resembling the dysregulation found in depressed individuals. The predictive value of these changes in the onset of depression remains to be determined.