Orbitofrontal dysfunction during the reward process in adults with ADHD: An fMRI study.

OBJECTIVE: The present study aimed to detect differences in the reward response between adults with attention deficit hyperactivity disorder (ADHD) and healthy controls (HCs) using functional magnetic resonance imaging (fMRI).

METHODS: The Iowa gambling task (IGT) was designed to explore participants' reward-related decision-making in relation to selections during risky behaviors. Twenty adults with ADHD and 20 HCs were enrolled. fMRI with a modified IGT was performed.

RESULTS: The adults with ADHD showed a poorer performance in terms of avoidance during risky behaviors. The fMRI results indicated that the adults with ADHD had significantly lower orbitofrontal cortex (OFC) activation. A positive correlation between performance in the IGT and brain activation in the OFC was detected.

CONCLUSIONS: The results suggested that the adults with ADHD exhibited abnormal OFC responses during decision-making.

SIGNIFICANCE: To the best of our knowledge, this is the first study to use fMRI to collect brain activation data while performing the IGT in adults with ADHD. Our findings suggest that deficits in reward processing in ADHD are still present during adulthood.