Childhood adversity in borderline personality disorder—a call for a more systemic approach to early intervention and prevention

Childhood adversity, often also referred to as early life maltreatment, is one of the most common risk factors for the development of mental health problems in adulthood (1). While the definitions of few diagnostic entities include adverse or traumatic events as a mandatory and causal factor (e.g., posttraumatic stress disorder or adjustment disorder), most mental disorders are currently classified by their clinical phenotypes, and irrespective of potential etiological pathways. The relationship between childhood adversity and borderline personality disorder (BPD) has been subject of scientific controversy for many decades. The opinions in this ongoing discussion range from childhood adversity being a very unspecific risk factor for BPD as for most other disorders to BPD being a disorder causally related to complex trauma (2, 3). The meta-analysis published by Porter and colleagues summarizes the current evidence on the association between adult BPD and childhood adversity with a particular focus on the specificity of this relationship as well as the different types of childhood adversity involved (4). In their synthesis of the current empirical data, Porter et al. (4) showed that adults with BPD had 14 times higher odds for childhood adversity compared to healthy comparisons. More importantly, adults with BPD also showed an odds ratio for childhood adversity of more than three when compared to other mental disorders (4). Thus, the current empirical basis suggests that BPD is a disorder that is at least more specifically linked to childhood adversity than many other mental disorders. In addition, Porter et al. (4) found that emotional abuse and neglect were clearly the types that showed strongest associations with adult BPD (4) suggesting that long-term and complex adversity within the family environment may go along with highest risk for the development of BPD. Although representing an important summary of the current evidence, the work by Porter et al. (4) leaves several remaining questions that need to be targeted by future research. One of these questions refer to the role of childhood adversity in the specific etiology of BPD. In this meta-analysis, more than 70% of individuals with BPD reported childhood adversity (as defined by the authors); however, this also means that almost 30% did not report a history of abuse and neglect—a fact that would clearly limit a diagnosis of BPD causally related to childhood adversity. However, additional types of childhood adversity might not have been captured in this analysis, or recall bias could have led to attenuated memories of adversity. A recent study investigated childhood adversity in adolescents with BPD compared to clinical controls confirming the significantly higher load of childhood adversity among those adolescents with BPD. More importantly, this study included experiences of abuse and neglect but additional problematic bonding experiences and family functioning and did not find a single BPD patient who reported non-adverse experiences within the family environment (5). In addition, another study on adolescent BPD revealed that compared to adults with BPD, adolescents showed less severe profiles of abuse and neglect (6). The limited data from early presentations of BPD may suggest that almost all individuals have experienced some but in some cases milder forms of childhood adversity. The second important question concerns the potential mechanisms that underlie the relationship between childhood adversity and BPD. Several biological alterations have been identified in individuals with BPD (there is, e.g., meta-analytic evidence for volumes of the limbic system (7) as well as functioning of the autonomous nervous system (8) and the hypothalamic–pituitary–adrenal axis (9)) that have also been linked to childhood