Neural systems underlying thought suppression in young women with, and at-risk, for depression.
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.
Department of Psychiatry and Behavioural Neurosciences, McMaster University, Room F130, Fontbonne Building, 50 Charlton Avenue E., Hamilton, ON, Canada L8N 4A6; McMaster Integrative Neuroscience Discovery and Study, McMaster University, 1280 Main Street West, Hamilton, ON, Canada L8S 4K1.
Caitlin L
CL
Carew
Andrea M
AM
Milne
Erica L
EL
Tatham
Glenda M
GM
MacQueen
Geoffrey B C
GB
Hall
D000293:Adolescent; D000704:Analysis of Variance; D001921:Brain / Q000098:blood supply / Q000473:pathology*; D001931:Brain Mapping; D003865:Major Depressive Disorder / Q000473:pathology* / Q000523:psychology*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D009043:Motor Activity / Q000502:physiology; D058958:Organs at Risk; D010100:Oxygen / Q000097:blood; D011569:Psychiatric Status Rating Scales; D012094:Repression, Psychology; D012306:Risk; D013850:Thinking / Q000502:physiology; D055815:Young Adult
D010100:Oxygen
Major depressive disorder; Risk; Thought suppression; Women; fMRI