Disrupted Relationship between Hippocampal Activation and Subsequent Memory Performance in Borderline Personality Disorder

Abstract Background : Borderline personality disorder (BPD) is associated with subjective reports of forgetfulness and deficits on tests of memory performance. However, it is not yet known whether individuals with BPD show different patterns of activation in the hippocampus during episodic memory encoding, especially for materials that are not emotionally-valenced. Methods : Participants with BPD (n=20) and non-psychiatric controls (n=21) completed a memory encoding task in which they viewed scenes without emotional content during functional magnetic resonance imaging scans. Subsequently, they completed a recognition memory test outside of the scanner and neural activation during the presentation of successfully remembered scenes was contrasted with scenes that were subsequently forgotten. Results : Controls exhibited significant left hippocampal activation during successful memory encoding, displaying greater activity during the presentation of subsequently remembered versus forgotten scenes, and the strength of this activation was related to their recognition memory performance. Although hippocampal activation was observed for the BPD group during successful memory encoding, it did not reach significance when implementing a non-parametric statistical approach. Additionally, individual hippocampal recruitment was not significantly correlated with recognition memory performance in the BPD group. The strength of this correlation, but not the overall magnitude of hippocampal activation, was significantly different between the groups. Limitations : Participants with BPD had comorbid psychiatric diagnoses and varied treatment histories. Whether patients and controls differentially perceived emotional content in the neutral scene memoranda was not tested. Conclusions : Memory problems in BPD may be partially explained by a disrupted relationship between hippocampal activation and successful memory encoding.