Deficits in sustained attention in adolescents with bipolar disorder during their first manic episode.

OBJECTIVES

Evaluate differences in sustained attention (SAT) and associated neurofunctional profiles between bipolar disorder type I (BD), attention-deficit/hyperactivity disorder (ADHD), and healthy comparison (HC) youth.

METHODS

Adolescent participants, aged 12-17 years, with BD (n = 30) and ADHD (n = 28) and HC adolescents (n = 26) underwent structural and functional magnetic resonance imaging (fMRI) while completing a modified Continuous Performance Task-Identical Pairs task. Attentional load was modifying in this task using three levels of image distortion (0 %, 25 % and 50 % image distortion). Task related fMRI activation and performance measures: perceptual sensitivity index (PSI); response bias (RB) and response time (RT); were calculated and compared between groups.

RESULTS

BD participants displayed lower perceptual sensitivity index (0 % p = 0.012; 25 % p = 0.015; 50 % p = 0.036) and higher values of response bias across levels of distortion (0 % p = 0.002, 25 % p = 0.001, and 50 % p = 0.008) as compared to HC. No statistically significant differences were observed for PSI and RB between BD and ADHD groups. No difference in RT were detected. Between-group and within-group differences in task related fMRI measures were detected in several clusters. In a region of interest (ROI) analysis of these clusters comparing BD and ADHD confirmed differences between these two groups.

CONCLUSIONS

Compared with HC, BD participants displayed SAT deficits. Increased attentional load revealed that BD participants had lower activation in brain regions associated with performance and integration of neural processes in SAT. ROI analysis between BD and ADHD participants shows that the differences were likely not attributable to ADHD comorbidity, suggesting SAT deficits were distinct to the BD group.