Diffusion-based brain correlates of adolescent resilience

573 

Abstract Submission 

Tiffany Ngan¹, Benjamin Sipes¹, Angela Jakary¹, Tara Samson¹, Yi Li¹, Eva Henje², Tony Yang¹, Olga Tymofiyeva¹

¹University of California, San Francisco, San Francisco, CA, ²University of Umeå, Umeå, n/a

Tiffany Ngan  
University of California, San Francisco
San Francisco, CA

Benjamin Sipes  
University of California, San Francisco
San Francisco, CA

Angela Jakary  
University of California, San Francisco
San Francisco, CA

Tara Samson  
University of California, San Francisco
San Francisco, CA

Yi Li  
University of California, San Francisco
San Francisco, CA

Eva Henje  
University of Umeå
Umeå, n/a

Tony Yang  
University of California, San Francisco
San Francisco, CA

Olga Tymofiyeva, PhD  
University of California, San Francisco
San Francisco, CA

Adolescent mental health has been an important growing concern over the past several years, especially following large post-COVID-19 increases in anxiety and depression [1]. Elucidating the neural correlates of mental wellbeing has become even more crucial, and resilience, described as "the ability to cope effectively and adapt in the face of loss, hardship or adversity" [2], has been established as a protective factor against mental illness [3]. However, structural and functional neuroimaging findings and approaches to operationalize resilience have been varied [4]. In this study we investigated two brain regions that have previously been associated with measures of resilience, the anterior cingulate cortex (ACC) and the insula, using a myelin-dependent node strength metric derived from DTI connectomics. We first hypothesized that resilience would be negatively associated with depression. We also hypothesized that trait resilience would be associated with node strengths of the ACC and the insula.

Healthy adolescents 14-18 years old (N=56 [42 female], mean age=16.16 years, SD=1.33 years) were recruited as a part of our research team's ongoing NIH-funded BrainChange study. Participants did not have any prior psychiatric diagnoses. Resilience was measured using the Connor-Davidson Resilience 10-item scale (CD-RISC, score range 0-40). Depression was measured using the Reynolds Adolescent Depression Scale-2 (RADS-2, score range 30-120). MRI data was acquired using a 3T GE MRI scanner at UCSF's Mission Bay campus. The scan included a T1-weighted sequence and a DTI sequence with 30 directions. The node strength was calculated as the sum of the connections from the hypothesized region to all other brain regions weighted by the average fractional anisotropy (FA) along the tractography streamlines [5].

Trait resilience and depression were negatively correlated (r=-0.33, p=0.01, Figure 1). We also found that ACC and insula node strength were positively correlated (r=0.27, p=0.04). Trait resilience was negatively correlated to node strength of the ACC (r=-0.34, p=0.01). No significant correlations were observed for the insula. We did not correct for multiple comparisons due to the exploratory nature of this project.

Our hypothesis that resilience would be negatively correlated with depression was confirmed, as was our hypothesis that resilience would be correlated with ACC node strength. This indicates that there are fewer and weaker connections to the ACC in individuals high in resilience, supporting it as a region of interest. The ACC is most functionally connected to areas implicated in both top-down and bottom-up emotion regulation [6], so our findings align with prior research showing that brain regions active in resilient individuals recruit areas implicated in emotional flexibility [7]. Existing literature has been mixed regarding whether or not higher activation in the ACC is indicative of higher or lower psychopathology, although this generally varies depending on which subregion of the ACC is being studied, as well as the type of mental health disorder. Previous research has found higher activation in the subgenual ACC in individuals diagnosed with major depressive disorder [8], which, given that we found more and stronger connections to the ACC in those lower in resilience, could indicate that the subgenual ACC is the driving force behind our observed results. Additionally, the positive relationship between ACC and insula node strength could reflect the involvement of the development of the salience network [9] in adolescent resilience.
Future directions include determining which subregions within the ACC contributed to our findings, as well as exploring other imaging metrics (e.g. resting state functional connectivity measures) to facilitate comparison to existing literature on resilience.

Psychiatric (eg. Depression, Anxiety, Schizophrenia) ¹

Diffusion MRI ²

PEDIATRIC

Psychiatric

Tractography

WHITE MATTER IMAGING - DTI, HARDI, DSI, ETC

Other - Depression; Resilience