Reward-related processes in pediatric bipolar disorder: a pilot study

Neuropsychological research on children with bipolar disorder (BPD) is scarce. Here, we examine reward-related behaviors in children with BPD using a Wheel of Fortune task in which subjects could win or lose money depending on their decisions. The intent of this work was to investigate performance differences between BPD and healthy children on a task that could be used in an fMRI environment to inform the neural substrates of reward processes in BPD. This study has no direct clinical implications. We hypothesized that relative to healthy children, children with BPD would select risky options more frequently, be less confident in a favorable outcome, and report stronger emotional responses to outcomes.

Forty-four children (22 BPD; 22 control) were compared on (i) decision-making with varying levels of risk, (ii) level of confidence in favorable outcomes, and (iii) responses to feedback. The task included a win-no win version and a lose-no lose version.

Patterns of selection did not differ between groups. In the lose-no lose task, BPD patients were less confident than controls in favorable outcomes. BPD patients expressed greater dissatisfaction than controls at not winning in win-no win, and greater satisfaction than controls at not losing in lose-no lose.

Limitations of this study included that the children with BPD were mostly in a depressed state, were medicated, and had co-morbid disorders.

This is the first experimental study to examine associations between pediatric BPD and reward-related behaviors. Although we failed to detect abnormalities in risky decision-making in children with BPD, we found significant differences between groups in both confidence ratings and response to feedback, consistent with our predictions. Our ultimate goal is to use this task in the fMRI environment to gain a better understanding of the neural correlates of reward-related processes in pediatric BPD.