Striatum gray matter reduction in males with an overactive behavioral activation system.

Using optimized voxel-based morphometry, we studied the relationship between gray matter volume in brain areas associated with reward and scores on a behavioral activation system measure (the Sensitivity to Reward scale) in a sample of 50 male undergraduates. Voxel-based morphometry analysis revealed a negative correlation between Sensitivity to Reward scores and gray matter volume in the dorsal striatum and prefrontal cortex. Results indicate that a reduced volume in the striatum might be associated with enhanced reward sensitivity and deficits in inhibitory control.