Reward processing in preadolescents with bipolar disorder: An fMRI study

Introduction: Reward processing dysfunction has long been implicated in adults with bipolar disorder. Nevertheless, little research has been conducted to examine whether such dysregulation also occurs in preadolescents with bipolar disorder. Methods: The current study will employ functional magnetic resonance imaging and conduct region-of-interest (ventral striatum and orbitofrontal cortex), whole-brain, and connectivity analyses to examine the similarities and differences in reward-related brain activation patterns, evoked by the Monetary Incentive Delay task, between 169 preadolescents with remitted bipolar disorder and 245 preadolescent healthy controls without personal and family history of Axis I disorders. Results: We hypothesize that activity in the prefrontal cortex (PFC) and the striatum would be elevated in preadolescents with remitted bipolar disorder during reward processing, relative to healthy controls. We also predict aberrant connectivity between the PFC and the striatum in response to reward in preadolescents with remitted bipolar disorder, relative to healthy controls. Conclusions: Early-onset bipolar disorder is often associated with remarkably long treatment delays and a persistently pernicious course of illness, underscoring the significance of studying mood disorders during this developmental period. Owing to the paucity of research and data on preadolescent bipolar disorder, accurate diagnosis in this population is challenging. Identifying objective markers of preadolescent bipolar disorder has the potential to enhance our ability to diagnose pediatric bipolar disorder accurately. Besides, early accurate diagnosis may improve our ability to intervene with appropriate treatments that may lead to a more benign course of bipolar disorder in adolescence and adulthood.