Cognitive dysfunction is worse among pediatric patients with bipolar disorder Type I than Type II

Abstract

Background: Impaired profiles of neurocognitive function have been consistently demonstrated among pediatric patients with bipolar disorder (BD), and may aid in the identification of endophenotypes across subtypes of the disorder. This study aims to determine phenotypic cognitive profiles of patients with BD Type I and II.

Methods: Subjects (N = 79) consisted of BD I (n = 27) and BD II (n = 19) patients and demographic and intellectually matched healthy controls (HC; n = 33) that completed a battery of neurocognitive tasks.

Results: Bipolar disorder Type I patients performed significantly more poorly compared to HC on all domains of cognitive function including attention, executive function, working memory, visual memory, and verbal learning and memory. BD I patients also performed more poorly compared to BD II patients on all domains of cognitive functioning with the exception of working memory, whereas BD II patients did poorly relative to HC only on verbal learning and memory.

Conclusions: Findings from the current study indicate that BD I patients are characterized by more severe cognitive impairment relative to BD II patients who show an intermediate pattern of performance between BD I patients and HC. Verbal learning and memory may effectively differentiate pediatric BD patients and controls, regardless of the subtype of BD, and may serve as a cognitive endophenotype for the disorder. Additionally, these findings move us closer to developing effective cognitive interventions tailored to specific subtypes of pediatric BD patients.

Figure 1

Performance on the on the neurocognitive domains for healthy comparison subjects and bipolar disorder type I (BD I) and type II (BD II) pediatric patients. Average z scores (with standard error bars) are presented.