The purpose of the current study was to provide insight into autobiographical memories (ABMs) of trust in patients with BPD compared to non-clinical controls. To our knowledge, our study is the first to provide information about ABMs of trust in patients with BPD.
The main result suggests that patients with BPD, when remembering trust, mainly recall memories in which their trust was failed by family members or romantic partners. Interestingly, they also recalled memories where they themselves failed to trust their family members. This result corresponds with findings on self-reported difficulties in trusting close others by patients with BPD .
The main focus of the current study was to analyze content of trust memories of patients with BPD and non-clinical control participants. To provide a comprehensive picture of such memories, we additionally reported frequencies of named trust objects (e.g. emotional reliability) and interaction partners as well as emotional valence, specificity and perceived relevance of trust memories.
The first aim of our study was to provide insight into what and about whom patients with BPD and non-clinical controls trusted. Current results suggest that especially trust into a person’s emotional reliability (30.1%) followed by trust into a person’s dependability (21.9%) and competency (24.0%) were the major trust objects named. Similarly, competency (14.4), dependability (16.6), and emotional reliability (14.4) were also the most frequently named categories in trust situations in which individuals did not show trust (situation 2). Participants of both groups reported most often to trust friends (27.6%) and romantic partners (20.3%). Besides this, they reported most often friends (20.0%), family (18.9%), acquaintances (15.5%) and romantic partners (14.4%) in situations in which they could have trusted but did not (situation 2). Emotional factors like empathetic listening and practical aspects like trusting into each other’s competencies make trust one of the most important factors for beneficial human relationships.
Our second aim was to examine differences in trust objects and interaction partners between patients with BPD and non-clinical controls. Patients with BPD did not report memories of trust into a person’s benevolence at all, while non-clinical controls did. This difference was significant.
Interestingly, in both groups, participants’ trust into a person’s benevolence was always related to unknown interaction partners. One explanation for this might be that benevolence (the entrusted interaction partner does not want to harm the trusting person’s emotional and physical well-being) is something that is usually expected as given in relationships with close others, while in interactions with unknown people one does not have any information about the entrusted person’s intentions. Patients with BPD do not seem to expect the benevolence of close others as given, however.
Patients with BPD showed a pattern to remember family members and romantic partners as interaction partners more often than non-clinical controls, while non-clinical controls remembered friends and strangers more often than patients with BPD. These differences were significant. In fact, patients with BPD did not remember any situation at all in which strangers were their interaction partners, which corresponds with the above described result on trust into someone’s benevolence. The result that patients with BPD remembered mostly situations with family members and romantic partners corresponds with the results from a study about memories of rejection . In a linguistic analysis of ABMs of rejection, patients with BPD remembered rejection by family members significantly more often than patients with MDD and healthy controls. Besides this, in our study patients with BPD indicated significantly more often than non-clinical controls that their trust was failed. This result corresponds with results from Guruprasad and Bohla  who found that participants described mostly situations that started with hope and optimism and ended with a failure of those positive expectations.
In the current study, an illustrative example of such a situation from a patient with BPD was:
“My car was broken and standing in front of my house. I had to go to the hospital and could not take care of it, so my dad promised to me to bring it to the garage. When I returned from the hospital, the car was still standing in the same place and my father obviously again did not stick to his word.”
It is striking that the patient who described this memory seems to have frequently experienced similar situations (my father obviously again did not stick to his word). As trust behavior is influenced by trust experiences , it does not seem surprising at all that patients with BPD reported difficulties trusting close others  Conway and Pleydell-Pearce’s  model about ABMs provides possible explanations for how trust experiences might influence current trust behavior. As described in the introduction, the model assumes that individuals contain sets of different self-schemata that are connected to specific goals. A person who has made repeated negative trust experiences with close others might develop the self-schema of “the betrayed one” with the goal to not be betrayed again. This goal could be attained by not showing trust towards close others in the first place.
The two groups differed in situations in which trust could have been shown but was not (situation 2). Patients with BPD recalled fewer memories about failing to trust into someone’s competency than non-clinical controls. One explanation for this finding could be that patients generally experience more situations in which they have to trust in a person’s competency, such as those in psychotherapy for example:
“During sessions with my therapist. I trust that we can take breaks whenever I want to. That we can do things without any pressure. That I can even say negative things out loud and still I will not be abandoned. That I am even allowed to scream. That he will not blame me, even if I will not accomplish my goals. That he will approach me. That there is not so much I can do wrong.”
Besides, in situations in which trust could have been shown but was not (situation 2), differences within interaction partner categories followed a similar pattern like in situation 1 – a situation in which trust was shown: here too, patients with BPD named family members and romantic partners as interaction partners more often than the control participants did. The difference within the category of family members was significant.
This result supports the idea that patients with BPD develop difficulties in trusting family members already early in life. Besides, this corresponds with research results indicating a high amount of childhood maltreatment in BPD [32, 48, 49] and the assumptions by Fonagy and colleagues that epistemic mistrust in BPD may be rooted in dysfunctional early attachment experiences .
The third aim of our study was to investigate whether alterations in ABMs from patients with BPD - for example, emotional valence of memories - can be found in ABMs of trust. In line with our hypotheses, patients with BPD related their ABMs of trust mostly to negative emotions and considered those memories as more relevant for their current lives than non-clinical controls. Prior studies on ABMs of patients with BPD found a tendency to recall mostly negatively valenced memories [25,26,27,28,29,30]. Bech, Elklit and Simonsen  argue that this tendency could be explained by a higher amount of negative life experiences in comparison to non-clinical controls. Another explanation is provided by Renneberg et al. , who state that this tendency could also reflect the extremely negative view patients with BPD have of themselves, other people, and the world in general.
Concerning relevance ratings, our results correspond with the results from Rosenbach and Renneberg  who also found that patients with BPD rated their ABMs of rejection as more relevant for their current lives than non-clinical controls. These results support the idea that current difficulties with trust or rejection are strongly influenced by prior negative experiences and speak for a heightened sensitivity towards these topics. Regarding the specificity of memories, our results suggest that patients with BPD do not display OGM when remembering trust, even when not controlling for comorbid depression. This result corresponds with findings by a majority of studies concerning OGM in BPD .
Limitations of the current study are that generalization of the current results is limited due to the small number of male patients in our study. Furthermore, BPD symptomatology was not assessed in the control group, as our assessment took place in a public and anonymous setting in which task duration was limited, which made it difficult to assess more sensitive information.
Current results emphasize the role of family members and romantic partners within memories of trust in patients with BPD. More specifically, patients with BPD mainly recall trust situations in which their trust was failed by family members and romantic partners. This is highly relevant for the current lives of the patients, as indicated by relevance ratings. Consequently, patients with BPD report mostly negative emotions when recalling ABMs of trust.