Adolescent suicide behaviors associate with accelerated reductions in cortical gray matter volume and slower decay of behavioral activation Fun-Seeking scores.

Distinguishing those at risk of making a suicide attempt from those who experience only suicidal ideations remains a significant clinical challenge. Longitudinal studies during early adolescence may provide insight into altered brain and behavioral developmental trajectories among those who develop suicide behaviors (SB). Here, we applied linear mixed effects regression models to several global brain volumes and psychiatric/behavioral measures from the Adolescent Brain Cognitive Development (ABCD) Study. We analyzed data from baseline up until the two-year follow-up, when participants were roughly 10 to 12 years of age. Individuals who had either ever endorsed or developed SB exhibited the greatest reductions in cortical gray brain matter volume. Those who developed SB exhibited the greatest increase in DSM5-depression scores and were the only group that maintained their levels of Behavioral Activation System (BAS) Fun-Seeking behaviors. Finally, we applied a Cross-Lagged Panel Modelling approach to the whole ABCD sample and found that baseline total cortical gray matter structure significantly predicted variation in BAS Fun-Seeking behaviors at the two-year follow-up, providing evidence supportive of a potential causal relationship between these two measures. Altogether, our findings suggest that differences in total cortical gray matter volume at 9-10 years of age may impact the development of behavioral approach systems. Altered development of behavioral approach systems and depressive symptoms distinguish youth who developed suicide behaviors during early adolescence.