A new brain-imaging study published in The American Journal of Psychiatry suggest scientists may be able to predict how likely children are to develop depression.
“Depression is a leading cause of disease burden,” said study author Pedro Mario Pan of Universidade Federal de São Paulo. “In adolescence, consequences of depressive episodes can be serious, such as peer-victimization, self-harm, and suicide. Moreover, children and adolescents with depressive disorder may fail to accomplish important psychological developmental milestones.”
“However, we still have limited knowledge about the underlying biological brain processes that cause depression in this age range. Previous researches show that the reward system is a promising causal mechanism implicated in depression etiopathogenesis.”
The researchers used resting-state functional MRI (fMRI) to examine the brain structure of 637 children who were between 6 and 12 years old. They then conducted a follow-up survey three years later.
Pan and his colleagues found that the connectivity of the ventral striatum, a region of the brain that supports reward-processing, predicted the development of depressive disorder. Increased ventral striatum connectivity was linked to an increase in odds of depressive disorder by about 50 percent.
“We were able to show that alterations in the connectivity of brain areas previously implicated in reward processing could predict depression after 3 years. One important region where our brain integrates reward cues, the ventral striatum, played a major role in this prediction,” Pan told PsyPost.
“Importantly, we analyzed data from a large community-based longitudinal sample of unmedicated adolescents. Therefore, our findings add to previous research connecting reward circuitry and adolescent depression.”
Depression is associated with reduced motivation and reduced response to rewards. The researchers believe that hyperconnectivity within brain’s reward network may be impeding the adequate processing of rewards. However, it is too early to conclude that increased striatum connectivity directly causes depression.
“Our observational design cannot prove causality, i.e. aberrant reward processing causing depression, since we would need experimental manipulation of reward or depression to do so,” Pan explained. “Further studies are needed to explore the potential use of this altered reward circuitry connectivity as a potential biomarker for increased risk of adolescent depression.”
The study, “Ventral Striatum Functional Connectivity as a Predictor of Adolescent Depressive Disorder in a Longitudinal Community-Based Sample“, was also co-authored by João R. Sato, Giovanni A. Salum, Luis A. Rohde, Ary Gadelha, Andre Zugman, Jair Mari, Andrea Jackowski, Felipe Picon, Eurípedes C. Miguel ,Daniel S. Pine, Ellen Leibenluft, Rodrigo A. Bressan, and Argyris Stringaris.