Increased sensitivity of insula to supraliminal faces in adults with histories of mood disorders and self-injury

Abstract

Background: Mood disorders are associated with neurobiological disruptions in subliminal and supraliminal emotion processing. There may be additional variation based on sex and the presence of self-injurious thoughts and behaviors (SITBs). Examining individuals in remission allows us to understand trait-like emotion processing characteristics that persist in the absence of symptoms. This study investigates neural processing in response to supraliminal and subliminal emotional stimuli based upon mood disorder diagnosis, sex, and SITBs.

Methods: Seventy-five participants with a history of any mood disorder (AMD; 52 female) and 27 healthy controls (HC; 14 female) completed a fMRI task presenting subliminal and supraliminal facial stimuli. Within the AMD group, 20 had no history of SITBs, 26 had histories of suicidal ideation only, and 27 had histories of both SI and self-injurious behavior. We examined activation of salience network regions of interest including the amygdala, insula, and subgenual anterior cingulate cortex (sgACC) during the task.

Results: AMD showed greater insula activation in response to happy faces relative to sad faces, which was not seen in the HC group. Males exhibited lower insula activation in response to sad faces relative happy faces, a pattern not seen in females. Individuals with SITBs demonstrated a lack of sgACC blunting during supraliminal versus subliminal trials.

Conclusions: We found different patterns of neural responses related to mood disorder status, sex, and SITBs. Findings highlight the importance of considering heterogeneity within diagnoses and examining neurobiological features in the context of remission.

Keywords: Emotion processing; Mood disorders; Neuroimaging; Self-injurious thoughts and behaviors; Subliminal; Supraliminal.