Patterns of attentional deficits and emotional bias in bipolar and major depressive disorder.

OBJECTIVES: Previous studies have reported deficits in selective attention and specific emotional biases in patients with bipolar (BP) disorder. The extent to which these distinguish BP patients from those with major depressive disorder (MDD) remain unclear. We aimed to examine the relationship between selective attentional impairments and emotional biases in symptomatic and euthymic BP, and symptomatic MDD patients.
DESIGN: A between-group design was used. The time taken for BP patients to perform on Stroop tasks was compared with that in patients with MDD, and a normal healthy control group.
METHODS: BP patients during manic (N = 14) and depressed (N = 13) episodes, and euthymia (N = 15), together with symptomatic patients with MDD (N = 17) and normal healthy controls (N = 18) were matched for IQ, gender, and age. Selective attention was measured using the Golden (1978) version of the Stroop task, and emotional bias, using the Lyon, Startup, and Bentall (1999) version of the emotional Stroop task.
RESULTS: On the Card Stroop, all patients were significantly slower than normal healthy controls on all three conditions. On the emotional Stroop Test, all patients were slower on neutral, positive, and negative conditions.
CONCLUSIONS: Our findings suggest that both BP and MDD patients demonstrate impaired performance on neutral and emotionally salient attentionally demanding tasks. The finding of impaired performance in all patients on baseline conditions in each task, however, indicates the need for inclusion of additional baseline conditions in these tasks in order to elucidate the nature of attentional impairments specific to these patient populations.