Differences and Similarities in Attentional Bias between Patients with Bipolar II Disorder and Borderline Personality Disorder

Background and purpose: The boundary between bipolar disorder and borderline personality disorder has always been a matter of debate. Despite the importance of this issue, only a few studies have directly compared these two groups. The main purpose of this study was to compare the cognitive profile of patients with bipolar disorder and borderline personality disorder in terms of attentional bias. Materials and methods: In this causal-comparative study, attentional bias was compared between 52 patients with bipolar II disorder and 50 patients with borderline personality disorder attending cognitive disorder and psychological clinics in Babol, Iran. Also, 50 healthy individuals were studied as control group. Dot-probe task was done and Young Mania Rating Scale was completed. Data were then analyzed using independent T-test. Results: The mean age and sex (F and M) of patients with bipolar II and borderline disorders and healthy controls were 25±1.73 (52% and 48%), 27.33±2.87 (61% and 39%), and 26.47±2.34 (50% and 50%), respectively. Mean scores for attentional bias in control group and patients with bipolar II and borderline disorders were 11.36±6.57 (P=0.0012), 19.67±6.85 (P=0.0025), and 16.26±5.85 (P=0.003), respectively.   Conclusion: In current study, both patient groups had poor performance in attentional bias tasks compared with control group. Patients with bipolar disorder showed more deficits in attention bias than patients with borderline personality disorder and healthy individuals. According to the differences in attention bias found in this study, cognitive studies may help to clarify the boundaries between bipolar disorder and borderline personality disorder.