For example, when frustrated, children with bipolar disorder had lower signal amplitude in the parietal lobe (P3 lead) than either children with severe mood dysregulation or controls. This difference indicates that the children with bipolar disorder have impairments in executive attention, the authors wrote.
In contrast, children with severe mood dysregulation had lower N1 (auditory evoked) event-related potential amplitude than children with narrow-phenotype bipolar disorder or controls, regardless of the emotional context. This difference reflected impairments in the initial stages of attention in the children with severe mood dysregulation, the investigators stated.
In post hoc analyses, the investigators determined that in the children with severe mood dysregulation, the N1 deficits were associated with the severity of symptoms of oppositional defiant disorder.
"Whereas the deficits in the narrow-phenotype subjects indicated impaired allocation of attention in the context of frustration, those in the severe mood dysregulation group indicated impairments in the initial stages of attention across emotional and non-emotional tasks," the investigators wrote.