Neural correlates of optimism and pessimism in healthy adolescents

706 

Abstract Submission 

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

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

Tara Samson  
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

Tiffany Ngan  
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

Adolescents face a mounting struggle against depression, with 5 million adolescents in the US experiencing at least one major depressive episode in the past year and relapse rates around 50% [2, 5]. Notably, dispositional optimism has a demonstrated strong negative association with adolescent depression with research suggesting optimism and depression may even arise from shared neural correlates in the amygdala and anterior cingulate cortex (ACC) [9, 10]. Prior work also links optimism with neural correlates in the putamen and ventromedial prefrontal cortex (vmPFC) [3, 4, 7]. Clarifying the neural underpinnings of optimism and pessimism could reveal how these traits render adolescents especially protected from or vulnerable to depression [1, 10]. We aim to (1) replicate the correlation between optimism and depressive symptoms in adolescents, extending the link to pessimism as well, (2) identify neural correlates of optimism and pessimism, and (3) propose a neural circuit underlying these traits in healthy adolescents.

117 healthy adolescents (15.9±1.3 yrs, 51 females) underwent a 3T MRI scan that included a T1-weighted sequence and a diffusion-weighted sequence with 55 directions reconstructed using High Angular Resolution Diffusion-Weighted Imaging (HARDI). Node strength was calculated as the sum of the connections from each region of interest to all other brain regions weighted by the average fractional anisotropy (FA) along the tractography streamlines (Figure 1) [8]. All participants self-reported on the Revised Life Orientation Test (LOT-R) and the Reynolds Adolescent Depression Scale-2nd edition (RADS-2). Our analyses focused on key regions of interest– the amygdala, ACC, putamen, and vmPFC. Note that the vmPFC corresponded to the medial orbitofrontal cortex (mOFC) in the AAL atlas in our study. We did not correct for multiple comparisons due to the exploratory nature of this analysis.

First, we confirmed a negative correlation between the level of self-reported depressive symptoms (RADS-2 T-score) and self-reported dispositional optimism (LOT-R) (r=-0.473; p<.001, Figure 2). We also found a positive correlation between depressive symptoms and dispositional pessimism (LOT-R) (r=0.450; p<.001).

Secondly, we found significant correlations between optimism scores and the structural node strength of the bilateral putamen (r=0.188; p=.045) and bilateral amygdala (r=0.209; p=.025). There was also a significant correlation between pessimism scores and the structural node strength of the bilateral vmPFC (r=-0.208; p=.027). We did not find any significant correlations with ACC node strength.

Our findings reinforce that dispositional optimism and pessimism are associated with depressive symptoms in healthy adolescents. Based on the significant associations between our regions of interest– the putamen, amygdala, and vmPFC– and optimism and pessimism scores, we theorize that the amygdalofugal pathway may contribute to optimistic and pessimistic tendencies in youth. The amygdalofugal pathway is a main efferent from the amygdala which links emotional motivations and drives arising in the limbic system (amygdala) to reward-driven actions in the striatum (putamen) and reward learning and memory in the medial frontal cortex (vmPFC). [11]. It follows that this system could also influence dispositional optimism and pessimism as forms of future reward prediction.

Future studies could advance this theory by investigating the associations between optimism and pessimism scores and the functional connectivity of the amygdalofugal pathway. Importantly, optimism is not a fixed trait. Treatments like cognitive behavioral group therapy can increase optimism in people with depression [6]. We hope that by deepening our understanding of the neural underpinnings of optimism and pessimism, we will discover better ways to foster optimism and protect against depression in vulnerable adolescents.

Psychiatric (eg. Depression, Anxiety, Schizophrenia)

Emotion and Motivation Other ¹

Early life, Adolescence, Aging

Connectivity (eg. functional, effective, structural) ²

Affective Disorders

Cortex

Development

Limbic Systems

MRI

Pediatric Disorders

Psychiatric Disorders

WHITE MATTER IMAGING - DTI, HARDI, DSI, ETC

Other - Optimism/Pessimism