ISSN 1225-8709 (Print)
ISSN 2005-7571 (Online)
Volume 25, Number 1 (1/2018)
Original Article <page. 9-15 >

Comparison of Cognitive Controls in Patients with Bipolar I Disorder and Their Unaffected First-Degree Relatives

Hyerim Yun, MD;Seonjin Woo, MD;Sang-Won Lee, MD;Bo-Hyun Jin, MD;Jungmin Woo, MD; and Seunghee Won, MD

Department of Psychiatry, School of Medicine, Kyungpook National University, Daegu, Korea

Objectives : This study intended to identify the deficits of cognitive control among patients with bipolar I disorder and their first-degree relatives, and identify the possibility of cognitive control as an endophenotype of bipolar disorder.

Methods : The study included three groups: euthymic states patients with bipolar I disorder (n = 55), unaffected first-degree relatives of probands with bipolar I disorder (n = 30), and a healthy control group (n = 51), that was matched on age, sex, and years of education. The AX version of the continuous performance test (CPT) was used to examine cognitive control. Error rate, correct response times of each subsets (AX, BX, AY, BY), and d' as an indication of accuracy sensitivity index were calculated. Psychopathology, intelligence, and psychomotor speed were also assessed.

Results : Patients with bipolar I disorder showed significantly worse error rates in the AX (p = 0.01) and BX (p = 0.02) subsets and d' (p = 0.05) than the others. They also showed more delayed correct response times than the healthy control group and first-degree relatives in all subsets (p < 0.01). But first-degree relatives showed neither high error rates nor delayed correct response times than healthy control group.

Conclusions : These findings suggest that cognitive control is impaired in bipolar I disorder but less likely to be an endophynotype of bipolar I disorder.


Key words : Bipolar disorder;Cognitive control;AX-CPT;First-degree relatives;Endophenotype.

PSYCHIATRY INVESTIGATION

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