Western Regional Meeting 2016, Carmel, California, January 28–30, 2016

226: DEFAULT MODE NETWORK ACTIVITY: TESTING FOR ASSOCIATION WITH EXTERNALIZING BEHAVIOR PROBLEMS WITH AND WITHOUT CALLOUS UNEMOTIONAL TRAITS

BC Walsh

M Dalwani

J Sakai

University of Colorado School of Medicine, Northglenn, CO

Purpose of Study Adolescents with externalizing behavior problems (conduct disorder (CD) and substance use disorders (SUD)) are a source of large social and economic costs. Such adolescents sometimes display high levels of callous-unemotional (CU) traits and recent work supports that the presence of CU identifies a distinct subgroup of youths with CD. We sought to test whether activity of the default mode network (DMN), a functional brain network involved in self-reflective thought, empathy, and foresight, is associated with these disorders.

Methods Used We collected 6 minutes of resting state functional magnetic resonance imaging for 20 patients with CD/SUD and CU, 21 patients with CD/SUD without CU, and 22 controls (all males 14–18 years). We used independent component analysis, a data-driven approach, to identify networks (i.e., clusters of voxels which activate together across time). We then utilized a standard template and spatial correlation to select the DMN. We tested: (1) whether the 3 groups differed significantly in DMN activity, (2) whether DMN activity was associated with severity of externalizing behavior problems within patients, and (3) whether DMN activity was associated with CU trait severity within patients.

Summary of Results Three-group comparisons revealed differences in one cluster including portions of the posterior cingulate cortex (PCC) and precuneus (Brodmann area (BA) 31). Subsequent two-group comparisons showed that both patient groups had significantly less activation in this cluster compared with controls. Our within-patient analysis showed that severity of externalizing behavior problems was negatively associated with activity of a cluster in the ventral and dorsal anterior cingulate areas (BA24/32), and positively associated with activity in a cluster within the PCC. Finally, within patients, severity of CU traits was negatively associated with activity in a cluster of the inferior parietal lobule (BA40). …