"If future research indicates that bipolar disorder and severe mood dysregulation are two separate disorders, this could guide parents and physicians toward the right treatments," said Dr Rich. "A good example is that medication prescribed for symptoms seen in severe mood dysregulation, such as stimulant medication, might be inappropriate for a child with classically defined bipolar disorder."
To assess whether irritability could be a diagnostic indicator for pediatric mania in bipolar disorder, the investigators looked for behavioral and psychophysiological correlates of irritability among 21 children with severe mood dysregulation, 35 with narrow-phenotype bipolar disorder, and 26 unaffected controls.
Severe mood dysregulation was defined as non-episodic irritability and hyperarousal without episodes of euphoric mood, and narrow-phenotype bipolar disorder was defined as a history of at least one manic or hypomanic episode with euphoric mood.
The children were evaluated with electroencephalography with electrodes recording signals from temporal, frontal, central and parietal sites as they performed the Posner task.