Background: The aim of this study was to examine whether patients with borderline personality disorder (BPD) have deficits in cognitive inhibition as measured with an anti-saccade eye task similar to patients with schizophrenia (Sz). Furthermore, we investigated whether these inhibition errors were more prominent among BPD patients with psychotic-like symptoms than among BPD patients without these symptoms.
Methods: An anti-saccade task was administered in 32 BPD patients (among them, 20 had with psychotic-like symptoms), 21 patients with recent onset schizophrenia (Sz), and 25 healthy controls (HC). The percentage inhibition errors in the anti-saccade task were the primary outcome variable, in addition, the percentage of anticipatory errors was measured.
Results: Sz patients showed more inhibition errors than HC and BPD (p<.001 and p<.05 resp.), whereas BPD patients scored in between Sz and HC. The difference with HC was significant as well (p<.05). BPD patients with psychotic-like symptoms showed more inhibition errors than BPD patients without these symptoms (p<.05). BPD patients showed more anticipatory errors than HC (p<.001), whereas Sz patients did not (p<.26).
Conclusion: The data demonstrate that inhibition deficits, as measured with anti-saccadic eye movement task, may be characteristic among BPD patients and in a larger extent in patients with psychotic-like symptoms. This inhibition deficit was distinct from a general predisposition to response impulsively as measured by anticipatory errors, which was found in the whole group of BPD patients. Psychotic-like symptoms may be an important target dimension for future BPD research and treatment.