title: Subclinical depression severity is associated with distinct patterns of functional connectivity for subregions of anterior cingulate cortex.
abstract: Depression is a prevalent psychiatric condition characterized by sad mood and anhedonia. Neuroscientific research has consistently identified abnormalities in a network of brain regions in major depression, including subregions of the anterior cingulate cortex (ACC). However, few studies have investigated whether the same neural correlates of depression symptom severity are apparent in subclinical or healthy subjects. In the current study, we used resting-state fMRI to examine functional connectivity for subregions of the ACC in N = 28 participants with subclinical levels of depression. In regression analyses, we examined relationships between depression severity and functional connectivity for pregenual ACC (pgACC), anterior subgenual ACC (sgACC), and posterior sgACC seed regions. Additionally, we examined relationships between ACC subregion connectivity and trait levels of positive and negative affect. We found distinct associations between depression severity and functional connectivity of ACC subregions. Higher depression severity was associated with reduced pgACC-striatum connectivity and reduced anterior sgACC-anterior insula connectivity. Consistent with resting-state findings in major depression, higher depression severity was also related to greater anterior sgACC-posterior cingulate connectivity and greater posterior sgACC-dorsolateral prefrontal connectivity. Lastly, there were distinct correlations between connectivity for anterior versus posterior ACC subregions and positive and negative affective traits. These findings provide novel support linking subclinical depression to the same neural substrates associated with major depression. More broadly, these results contribute to an emerging literature on dimensional approaches to psychiatric illness.
authors.affiliation: Department of Psychiatry, University of Wisconsin-Madison, 6001 Research Park Boulevard, Madison, WI 53719, USA; Department of Psychological Sciences, University of Missouri-St. Louis, One University Boulevard, St. Louis, MO 63121, USA. Electronic address: philippic@umsl.edu.
authors.forename: Carissa L
authors.initials: CL
authors.lastname: Philippi
authors.affiliation: Department of Psychiatry, University of Wisconsin-Madison, 6001 Research Park Boulevard, Madison, WI 53719, USA.
authors.forename: Julian C
authors.initials: JC
authors.lastname: Motzkin
authors.affiliation: Department of Psychiatry, University of Wisconsin-Madison, 6001 Research Park Boulevard, Madison, WI 53719, USA.
authors.forename: Maia S
authors.initials: MS
authors.lastname: Pujara
authors.affiliation: Department of Psychiatry, University of Wisconsin-Madison, 6001 Research Park Boulevard, Madison, WI 53719, USA. Electronic address: mrkoenigs@wisc.edu.
authors.forename: Michael
authors.initials: M
authors.lastname: Koenigs
mesh_terms: D001931:Brain Mapping; D003863:Depression / Q000503:physiopathology*; D005260:Female; D006179:Gyrus Cinguli / Q000503:physiopathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009434:Neural Pathways / Q000503:physiopathology; D017397:Prefrontal Cortex / Q000503:physiopathology; D011569:Psychiatric Status Rating Scales; D012044:Regression Analysis; D012146:Rest; D012720:Severity of Illness Index
keywords: Affect; Default mode network; Depression; Functional connectivity; Mental illness; Resting-state