The Role of Gender in Borderline Personality Disorder

Scientific Background Studies have shown that people with BPD experience increased levels of stigma and that this has harmful effects on their mental health (e.g., Rüsch et al., 2006; Quenneville et al., 2020; Ring \& Lawn, 2025; van Schie et al., 2024). The role of sex (biological or sex assigned at birth) and gender (socially and culturally constructed gender) aspects in the stigmatization experienced by individuals with BPD has been scarcely investigated to date. It has been hypothesized, however, that the heightened experience of stigmatization is partly related to the fact that the group of individuals with BPD studied predominantly belongs to the female sex assigned at birth (Quenneville et al., 2020). BPD is a severe mental illness characterized by, among other things, unstable emotions, relationships, and identity (APA, 2013). The prevalence ranges from 0.7% to 2.7% in the general population and from 6% to 22% in clinical samples (Leichsenring et al., 2024). In the latter, women are significantly overrepresented at over 70%, while interview-based epidemiological studies find comparable rates among men and women (Grant et al., 2008; Tomko et al., 2014). Feminist-oriented studies criticize psychiatric classification systems for reproducing patriarchal gender stereotypes: Thus, traits considered "too masculine for a woman" (e.g., the criterion of "inappropriate anger") as well as traits with "too feminine" connotations (e.g., the criterion of "mood instability") would be pathologized and thereby stigmatized (Cohen \& Hartmann, 2021; Fellows, 2023).

The few studies that have examined the role of gender in people with BPD have focused on samples of people with sexual and gender diversity (SGD)-that is, samples comprising individuals with a sexual orientation other than heterosexuality or a gender identity other than cisgender (where gender identity aligns with the sex assigned at birth). These studies revealed associations between gender and homosexual or bisexual orientation and BPD symptoms; however, the authors emphasize the insufficient data and the need for further research (Shu et al., 2024; Denning et al., 2022). Recent experimental studies also point to gender-dependent differences in social stigmatization: For instance, male-coded BPD vignettes were rated with more anxiety and perceived danger, while female-coded ones were rated with more compassion by the general population (Masland \& Null, 2022; Brown, 2024). Together with the knowledge that invalidating relationship experiences are considered central etiological factors in the development of BPD (e.g., Linehan, 1993; Porter et al., 2020; Bateman \& Fonagy, 2010), these findings underscore the importance of conducting a differentiated examination of gender-specific relationship and stigmatization experiences in BPD.

Studies that focused on gender-related stigmatization and its impact on mental health also primarily examined SGD samples (Swann et al., 2024; Liu et al., 2025; Scandurra et al., 2020). Experiences of gender-related rejection among transgender and gender nonconforming (TGNC) adults were associated with poorer mental health via internalized trans-negativity-that is, internalized negative attitudes toward trans\* individuals-but this effect was reduced with higher mentalization ability (Scandurra et al., 2020), suggesting that mentalization may serve a protective function in this context.

Mentalization describes the ability to explain one's own and others' behavior based on internal states, while maintaining an appropriately curious, open, and "correctable" attitude. Mentalization, as a kind of "psychological buffer" against the effects of aversive experiences on stress and mental health, has frequently been discussed as a resilience-promoting ability (Fonagy et al., 2019). Mentalization develops in early attachment relationships through "social biofeedback" (Gergely \& Watson, 1996) as early as childhood, as the child receives feedback about their internal states (affective mirroring) from their immediate environment. Similarly, Koivisto et al. (2022) hypothesized that gender stereotypes might be relevant to the experience of stigmatization among patients with BPD: Rigid self-invalidations observed in a mentalization-based therapy (MBT) group could be associated with female gender stereotypes, which children exhibiting "feminine" behavior internalized as an "Alien Self" through feedback from their environment. In mentalization theory, the "Alien Self" refers to the internalization of a self-image that corresponds, for example, to destructive, incongruent "mirrorings" of one's own experience by the environment (Fonagy et al., 2018).

For example, a belief such as "I am manipulative" may become part of a person's self-concept due to frequent attribution by those around them, yet it may (unconsciously) feel foreign to them in their own experience and remain difficult to regulate effectively. Based on findings regarding the increased stigmatization of BPD vignettes coded as male (Masland \& Null, 2022), it could be analogously assumed for individuals perceived as male that "male gender stereotypes" contribute to the formation of an Alien Self (e.g., "I am dangerous"). While MBT was developed specifically for the treatment of BPD and its core goal is to improve mentalization ability, including support in dealing with the Alien Self, it must also be noted here that gender has been neglected thus far.

To address the long-standing neglect of the significance of sex and, in particular, gender in theories and practices regarding the treatment of borderline personality disorder, this research project aims to 1) examine gender-related relationship and self-experiences in individuals with BPD and 2) conduct a pilot study on the use of the Single-Category Implicit Association Test (adapted from von Hippel et al., 2018) to investigate implicit thought processes related to sex and BPD.

Project Objectives This project aims to investigate, for the first time, the significance of gender in attachment relationships and self-perception among 15 individuals with BPD using the Critical-Constructivist Grounded Theory (CCGT; Levitt, 2025) method. Furthermore, the research toolkit in this area is to be expanded. Therefore, the study will also examine the extent to which Single-Category Implicit Association Tests (SC-IATs, by Hippel et al., 2018) can be validly used in the target population to investigate implicit gender- and BPD-related thought processes. Since the aim of the study is not limited to the exclusive examination of gender but also takes "sex" into account, the term "gender" is used in the following for summary purposes. Correlations with self-report measures of relationship and self-experience will be explored.

Endpoints and Hypotheses Research Question 1: What gender-related relationship and self-experiences can be identified in individuals with BPD? How are these experiences related to mentalization ability (as measured by coded data and self-reports), as well as to well-being, quality of life, patriarchal attitudes within the family, and psychological symptoms (as reported by the participants)? Research Question 2: Is there preliminary evidence that Single-Category Implicit Association Tests (SC-IATs) are suitable and reliable instruments for measuring implicit gender- and BPD-related thought processes in people with BPD? Primary Endpoints Research Question 1: A conceptual description of the significance of gender in relationships with oneself and others among individuals with BPD, based on a hierarchical categorical structure and taking structural power dynamics into account.

Research Question 2: D-scores (ratio of reaction times between experimental blocks), stimulus accuracy (proportion of correct trials per stimulus/proportion of all trials per stimulus), internal consistency of the SC-IATs, indications of multicollinearity (intercorrelation of D-scores), and variance

Secondary Endpoints Research Question 1: Superordinate and subordinate categories, identification of relevant contextual factors, differential typologies, alignment of the summarized main findings with patients' experiences, descriptive correlations with quantitatively measured psychosocial constructs Research Question 2: Duration of administration, error rates, indications of convergent validity (exploratory, correlation between D-scores and explicit measures), participant acceptance (qualitative feedback), exploratory correlations with the quantitatively measured psychosocial constructs

Study population Participants The study aims to recruit 15 individuals diagnosed with BPD (based on psychological, psychiatric, or medical evaluations, with the most recent diagnosis made no more than 2 years ago) and representing a range of gender identities (target: N=5 cis female, N=5 nonbinary/trans/gender-nonconforming/other self-defined identities, N=5 cis male).

The primary focus of the study is to investigate the role of gender in individuals with BPD and to evaluate a research instrument in this area; therefore, it is necessary to conduct the study among a group of individuals with BPD and, in some cases, members of a vulnerable group based on a non-binary or trans\* gender identity.

Inclusion and Exclusion Criteria Inclusion and exclusion criteria are assessed by psychologists holding at least a bachelor's degree through a self-report questionnaire. The presence of a borderline personality disorder diagnosis is verified by obtaining existing psychological and psychiatric diagnostic results that were conducted within the last 2 years as part of psychological or psychiatric care and/or study participation. This retrieval of diagnostic results is based on a waiver of confidentiality provided by the participants.

Inclusion Criteria:

1. Signed informed consent form 2. Individuals of all genders (target: n=5 with female gender identity, n=5 with nonbinary/trans\*/gender-non-conforming (TGNC) gender identity, n=5 with male gender identity) between the ages of 18 and 65 at the time of consent 3. Individuals with a BPD diagnosis made within the last 2 years (ICD-10: F60.3; DSM-5: 301.83, ICD-11: Borderline qualifier) 4. Understanding of the study procedure, ability and willingness to participate 5. The participant is able to read and understand the informed consent form and can provide a written, personally signed, and dated informed consent form.

Exclusion Criteria

1. Acute suicidal ideation or acute psychotic symptoms reported by the patient or suspected 2. Insufficient language skills

Recruitment measures and materials The majority of recruitment takes place among participants in the study "Mentalization-based treatment versus bona-fide treatment for patients with Borderline Personality Disorder in Germany (MAGNET): a prospective, multi-center randomized controlled trial" (S-493/2023). Only those participants who indicated in the MAGNET study consent form that they consent to being contacted for further studies and have not withdrawn this consent will be contacted.

For the purposes of Research Question 1, theoretical sampling (Glaser and Strauss, 1967) is applied during recruitment. Here, data collection takes place in several rounds (Levitt, 2021). Initially, participants with different characteristics that appear relevant to the topic (here: various gender identities) are recruited. Based on the ongoing data analysis for Research Question 1, subsequent rounds will specifically invite individuals with experiences that have been underrepresented thus far. This allows for the consideration of variations in characteristics whose relevance only becomes apparent during the analysis.

In addition, individuals with diverse gender identities may be recruited through the Institute for Psychosocial Prevention and Psychotherapy at Heidelberg University Hospital using flyers (posted at the institute, on the website, and distributed during ini

• Correlations Between Qualitative Category Frequencies and Psychosocial Construct Scores [Срок оценки: At baseline]
• SC-IAT Administration Duration [Срок оценки: At baseline]
• SC-IAT Convergent Validity [Срок оценки: At baseline]
• SC-IAT Participant Acceptance [Срок оценки: At baseline]
• Exploratory Correlations Between SC-IAT D-Scores and Psychosocial Construct Scores [Срок оценки: At baseline]
• Participant-Rated Applicability of Qualitative Findings to Own Experience [Срок оценки: Through completion of qualitative analysis, approximately 6 months after baseline]
• Participants' qualitative Feedback to Qualitative Findings [Срок оценки: Through completion of qualitative analysis, approximately 6 months after baseline]