Attachment orientations and borderline personality features: the mediating role of difficulties in interpersonal emotion regulation

Abstract

Background

Insecure attachment predicts borderline personality (BP), with emotion regulation widely recognized as a key mediator of this association. While interpersonal difficulties are central to BP, most studies have focused on intrapersonal emotion regulation, overlooking its interpersonal forms. Given the importance of understanding emotional and relational dysfunctions in BP, this study examined difficulties in Interpersonal Emotion Regulation (IER), investigating the role of maladaptive strategies—venting and excessive reassurance-seeking—as mediators in the relationship between attachment insecurity and BP.

Methods

A total of 420 adults completed self-report measures assessing BP features (PAI-BOR: affective instability, identity disturbances, negative relationships, and self-harm), attachment orientations (ECR-12: attachment anxiety and attachment avoidance), and IER difficulties (DIRE: venting and reassurance-seeking). Pearson’s correlations tested associations among variables, and a path analysis was conducted, using attachment anxiety and avoidance as exogenous variables, IER difficulties as mediators, and BP features as outcome variables.

Results

Attachment anxiety was positively associated with all BP features and greater difficulties in IER (venting and reassurance-seeking). IER mediated the relationship between attachment anxiety and BP features, with venting significantly mediating all BP dimensions.

Conclusions

Findings highlight a self-perpetuating cycle of relational difficulties and emotional dysregulation in BP, with IER playing a crucial role. Excessive reliance on others for emotional regulation, likely stemming from mentalization impairments, may lead individuals with BP and anxious attachment to externalize distress, reinforcing negative moods and straining relationships. Psychological interventions should focus on breaking this cycle by enhancing emotion regulation abilities, fostering autonomy, and reducing maladaptive dependence on others for emotional relief.

Introduction

Emotion dysregulation and unstable relationships are core features of Borderline Personality (BP), which ranges in severity along a psychopathological spectrum, with Borderline Personality Disorder (BPD) representing its most extreme manifestation [3]. While various theoretical models of BP place differing emphasis on the roles of emotion dysregulation [60] and attachment or mentalization difficulties [8], these aspects are often viewed as interrelated. Indeed, individuals with BP are believed to exhibit heightened emotional reactivity to perceived interpersonal threats, leading to self-harm behaviours aimed at both regulating intense emotions and fulfilling interpersonal needs [33, 94].

From an attachment theory perspective, interpersonal difficulties in BP are thought to arise from maladaptive mental representations of self and others [34, 58]. Research consistently shows that individuals with BP features tend to perceive others as malevolent [4, 6, 26, 45] and have negative self-representations [55, 89, 90]. Supporting this view, research on adult attachment consistently demonstrates a strong connection between BPD and insecure attachment styles, alongside a negative association with secure attachment [1, 54, 81]. Interview-based assessments have revealed that individuals with BPD often exhibit preoccupied and unresolved-disorganized attachment states of mind, which are disproportionately prevalent compared to other disorders [5, 35, 88]. Meanwhile, self-report studies focusing on dimensions of anxiety and avoidance in adult romantic attachments suggest that attachment anxiety is most strongly linked to BP [84, 92], particularly in relation to heightened sensitivity to abandonment, though attachment avoidance may also contribute by increasing the likelihood of inappropriate anger responses [59].

The impairment of emotion regulation in BP is well-documented, with evidence of infrequent use of adaptive ER strategies and reliance on maladaptive ones (for meta-analyses see [14, 24, 85]). Individuals with BPD are less likely to use reappraisal, problem-solving or acceptance-based strategies [14, 24], and commonly employ strategies such as suppression [26, 63, 67, 70], rumination [19, 78, 79] and avoidance [20, 49, 83] to regulate emotions. Neuroimaging studies have further corroborated these findings, demonstrating dysfunction in the fronto-limbic brain circuits involved in emotion regulation in individuals with BPD [39–41, 57].

Recent frameworks have sought to integrate attachment and emotion regulation, positing attachment theory as a model of understanding emotion-regulation abilities [71, 73, 80]. Although the motivational attachment system is universally activated in response to distress, the behavioural, emotional, and regulatory responses vary depending on an individual’s attachment history. According to these recent frameworks, securely attached individuals tend to manage distress by effectively engaging their attachment system, drawing on internalized representations of supportive attachment figures or seeking external support. These strategies promote emotional flexibility and adaptive emotion regulation. In contrast, individuals with avoidant attachment often respond to activation of the attachment system by employing deactivating strategies, suppressing or inhibiting emotional experiences and distancing themselves from others [12, 72, 91]. Conversely, individuals with anxious attachment tend to hyperactivate their attachment system with anxious internal attachment figures, which can lead to maladaptive strategies such as rumination and catastrophizing, which exacerbate emotional distress [15, 44, 72]. In the context of BP, research highlights the mediating role of emotion regulation in this association, where secure attachment appears to serve as a protective factor against BPD by fostering the use of positive emotion regulation strategies [53]. Instead, maladaptive emotion regulation strategies seem to mediate the association between attachment orientations and BP features [67, 70, 75].

Despite these insights, most studies have focused primarily on intrapersonal emotion regulation processes, neglecting the relational aspect of emotion regulation within social interactions, which is especially compromised given the significance of interpersonal difficulties in BP. Interpersonal Emotion Regulation (IER) refers to regulatory efforts within social interactions, where individuals rely on others to manage their emotions [27, 65, 66, 93]. According to a recent study [67, 70], higher attachment anxiety is associated with a greater propensity for IER use, while higher attachment avoidance is associated to reduced reliance on IER strategies, reflecting the imbalance between hyper-activation and deactivation of the attachment system characteristic of insecure attachment styles. On the one hand, IER may enhance social support during emotional distress, thereby mitigating psychological suffering in case of distress [62]. For example, a study demonstrated that soothing acted as a mediator between attachment anxiety and psychological distress, though this effect was reduced when controlling for social support [37]. On the other hand, excessive reliance on others in case of distress can exacerbate emotion dysregulation, potentially worsening symptoms of psychopathology [7, 46]. This could be particularly true in the case of BP, where impairments in interpersonal competencies can hinder the ability to effectively seek support for emotion regulation. Excessive reassurance-seeking and venting are examples of maladaptive forms of IER associated with BP [28, 65, 66]. Moreover, a recent study found that individuals with BPD features report lower efficacy in IER and perceive their partners as less willing to assist with emotion regulation [48], underscoring the negative impact of maladaptive attachment representations on the effectiveness of IER. However, to the best of our knowledge, no studies have yet explored the potential mediating role of IER in the relationship between attachment styles and BP features.

Building on this foundation, the current study aimed to explore the hypothesis that IER difficulties mediate the relationship between attachment insecurity and BP. We anticipate that different forms of attachment insecurity (anxiety versus avoidance) would correspond to distinct tendencies in IER, which would, in turn, have varying effects on BP features. Specifically, for individuals with attachment anxiety, it was predicted that higher levels of dysregulation, characterized by excessive use of venting and reassurance-seeking strategies, would intensify BP features. For those with attachment avoidance, the mixed findings in existing literature prevent definitive predictions. However, it was hypothesized that these individuals’ reluctance or difficulty in seeking support from others during times of distress could serve as a risk factor for BP. Therefore, ultimately, this study aims to enhance our understanding of how IER influences the development and dynamics of BP.

Method

Participants

The minimum required sample size was estimated a-priori on the basis of the simulation study conducted by Sim and colleagues (2022), who conducted a series of Monte Carlo simulations to determine the minimum required sample sizes for simple and complex mediation models. For average effect sizes of the indirect effects, the to-be-reached sample sizes were 227 participants for a simple mediation model (in which the effect of an independent variable X on a dependent variable Y is intervened thorough a mediator M) and 387 participants for a complex mediation model (involving two mediators, as in the present study; partial mediation, percentile bootstrap method).

Volunteers were recruited online via social media posts and snowball sampling methods to complete electronic questionnaires. The inclusion criteria were: (a) being aged 18 years or older; (b) being fluent in Italian; and (c) providing complete responses to all questionnaires (no missing data). The final sample consisted of 420 adults, including 294 females (70.00%), 124 males (29.52%), and 2 participants who identified as other (0.48%). The participants’ ages ranged from 18 to 73 years, with a mean age of 37.16 and a standard deviation of 11.71. This study received approval from the Ethical Committee of the University of Padua (protocol 2019–035). Informed consent was obtained from all participants included in the study.

Instruments

In the present study, the following self-report measures were used.

Borderline features scale of the Personality Assessment Inventory (PAI-BOR[74])

The PAI-BOR is a 24-item self-report measure that assesses features associated with BP (total score: α = 0.86). It is composed of the subscales Affective Instability (e.g., “My mood can shift quite suddenly”), Identity Problems (e.g. “My attitude about myself changes a lot”), Negative Relationships (e.g. “My relationships have been stormy”), and Self-harm (e.g. “When I am upset, I typically do something to hurt myself”). These items are rated on a four-point Likert scale (ranging from 0 = “false” to 3 = “very true”). The Italian version of the PAI-BOR has demonstrated reliability and validity in non-clinical samples [76]. In the present study, all subscales demonstrated good internal consistency, with Cronbach’s alpha values ranging from 0.69 to 0.78.

Experiences in Close Relationships-12 (ECR-12 [56])

The ECR-12 is a self-report 12-item questionnaire used to examine adult attachment style, based on their perceptions and emotional experiences in romantic relationships. It is composed of two 6-item subscales, Attachment Anxiety (e.g., “I worry that romantic partners won’t care about me as much as I care about them”) and Attachment Avoidance (e.g., “I don’t feel comfortable opening up to romantic partners”), with higher scores indicating more anxious and avoidant attachment styles, respectively. The Italian version of ECR-12 has previously shown psychometric properties (respectively, α = 0.85 for the Anxiety subscale and α = 0.86 for the Avoidance subscale) [13]. In the present study, internal consistency was acceptable for the Anxiety subscale (α = 0.72), whereas the Avoidance subscale exhibited lower reliability (α = 0.63).

Difficulties in Interpersonal Emotion Regulation (DIRE [28])

The DIRE is a scenario-based measure that evaluates clinically relevant difficulties in interpersonal emotion. For each of the three scenarios presented (feeling upset about a time-sensitive project that needs to be completed for school or work; fighting with a significant other; and thinking that friends have been avoiding you), participants are asked to rate how distressed they would feel in that scenario on a continuous scale ranging from 0 (“not at all distressed”) to 100 (“extremely distressed”) and, then, they are asked to indicate the likelihood that they would respond in the way described in each of 12 item, using a Likert scale ranging from 1 (“very unlikely”) to 5 (“very likely”). The DIRE allows the assessment of two forms of difficulties in interpersonal emotion regulation: Vent (e.g. “Raise your voice or criticize your friends to express how you feel”) and Reassurance-seek (e.g. “Keep asking for reassurance”). In the validation study of the Italian version of the DIRE [69], good internal consistencies have been reported for both the Vent (α = 0.76) and Reassurance-seeking (α = 0.87) subscales. In the present study, good internal consistencies have been reported for both the Vent (α = 0.76) and Reassurance-seeking (α = 0.89) subscales.

Results

Descriptive statistics and preliminary analyses

Table 1 illustrates descriptive statistics for the variables measured in the present study. Skewness values were in all cases comprised between − 1 and + 1 (as recommended by [86]), except for the Self-harm subscale of the PAI-BOR. A square root transformation was sufficient to bring the skewness value of this variable within the accepted range (0.02). To further test the normality assumption, we computed Mardia’s multivariate skewness coefficient, using the calculator provided by Cain, Zhang, and Yuan [18]. According to Bollen [11], if the Mardia’s coefficient is lower than p(p + 2), where p is the number of observed variables involved in the analysis, then the combined distribution of the variables can be considered as multivariate normal. In the present study, this coefficient was 3.52, which was largely lower than the threshold value (80). This result suggests that the multivariate distribution of our variables was fairly normal and that parametric statistics could be applied.

Table 1.

Descriptive statistics for the selected variables (numbers refer to raw scores)

	Total samplea	Femalesa	Malesa	Skewnessb
Attachment anxiety (ERC-12)	25.60 (5.81)	25.64 (5.80)	25.47 (5.88)	− 0.09 (0.11)
Attachment avoidance (ERC-12)	22.65 (2.89)	22.74 (2.89)	22.38 (2.85)	0.14 (0.11)
Reassurance-seeking (DIRE)	13.49 (4.91)	13.53 (4.80)	13.39 (5.20)	0.47 (0.11)
Venting (DIRE)	18.13 (6.32)	18.59 (6.35)	17.12 (6.14)	− 0.10 (0.11)
Affective instability (PAI-BOR)	6.44 (3.78)	6.67 (3.64)	5.83 (4.05)	0.50 (0.11)
Identity problems (PAI-BOR)	7.92 (4.41)	8.54 (4.33)	6.40 (4.20)	0.18 (0.11)
Negative relationships (PAI-BOR)	7.67 (3.49)	7.93 (3.34)	7.01 (3.76)	0.19 (0.11)
Self-harm (PAI-BOR)	1.57 (0.98)	1.56 (0.97)	1.58 (1.03)	0.02 (0.11)

^ameans and standard deviations

^bskewness values and standard errors

Potential gender differences were then analyzed. For the PAI-BOR, a MANOVA on the four subscales revealed a significant main effect of gender [Wilk’s λ = 0.93, F(4, 412) = 7.32, p < 0.001, η_p² = 0.07]. The follow-up univariate analyses indicated that the effect of gender was significant on the Affective Instability [F(1, 415) = 4.37, p = 0.037, η_p² = 0.01], Identity Problems [F(1, 415) = 21.61, p < 0.001, η_p² = 0.05], and Negative Relationships subscales [F(1, 415) = 6.20, p = 0.013, η_p² = 0.02], but not on the Self-harm subscale [F(1, 415) = 0.02, p = 0.86, η_p² = 0.00]. In all cases, the PAI-BOR scores were higher for females than for males (see Table 1). Similar MANOVAs on the other two questionnaires showed a marginal effect of gender on the DIRE [Wilk’s λ = 0.98, F(2, 415) = 2.72, p = 0.067, η_p² = 0.01], but no effect on the ECR-12 [Wilk’s λ = 0.85, F(2, 415) = 0.85, p = 0.42, η_p² = 0.00]. For the DIRE, the follow-up analyses suggested that the differences could be attributed to the Reassurance-Seeking subscale [F(1, 416) = 4.74, p = 0.030, η_p² = 0.01], but not to the Venting subscale [F(1, 416) = 0.08, p = 0.78, η_p² = 0.00]. In the first case, females achieved again higher scores than males (see Table 1). In summary, these results suggest that females had higher levels of affective instability, had more identity problems and more negative relationships, and were more likely to use reassurance-seeking strategies.

Regarding age and education, Table 2 shows that age was negatively associated with the Attachment Avoidance of the ECR-12 (p = 0.004). On the other hand, education was positively associated with the Reassurance-seeking subscale of the DIRE (p = 0.002) and negatively associated with all the PAI-BOR subscales (all ps ≤ 0.001). Thus, older participants were more likely to use reassurance-seeking strategies, but less likely to have an avoidant attachment style and to report features associated with BP.

Table 2.

Pearson’s correlations between the selected variables

	1	2	3	4	5	6	7	8
1. Attachment anxiety (ERC-12)	-
2. Attachment avoidance (ERC-12)	− 0.23**	-
3. Venting (DIRE)	0.31**	− 0.13**	-
4. Reassurance-seeking (DIRE)	0.41**	− 0.15**	0.47**	-
5. Affective instability (PAI-BOR)	0.33**	− 0.06	0.41**	0.14**	-
6. Identity problems (PAI-BOR)	0.50**	− 0.09	0.38**	0.26**	0.72**	-
7. Negative relationships (PAI-BOR)	0.31**	− 0.13**	0.36**	0.20**	0.60**	0.56**	-
8. Self-harm (PAI-BOR)	0.18**	− 0.04	0.28**	0.12**	0.48**	0.42**	0.36**	-

**: p ≤ 0.01

Pearson’s correlations

Table 2 illustrates Pearson’s correlation between the measures obtained from PAI-BOR, ECR-12 and DIRE questionnaires. As can be noted, all the PAI-BOR subscales were positively associated with Attachment Anxiety, Reassurance-seeking and Venting (all ps < 0.010). This suggests that participants who reported more features linked with BP were also more likely to have an anxious attachment style and to use venting and reassurance-seeking strategies. For attachment avoidance, there was only a significant negative relation with the Negative Relationships subscale of the PAI-BOR (p = 0.005).

In addition, the use of Venting and Reassurance-Seeking strategies was positively associated with Attachment Anxiety (all ps < 0.001) but negatively associated with Attachment Avoidance (all ps < 0.005).

Path analyses

To determine which variables predicted BP features, we performed a path analysis using the pathj module of Jamovi, which is based on the lavaan R package [77] and allowed us to test indirect mediation effects. Attachment anxiety and attachment avoidance were considered as the exogenous variable (together with age and education), reassurance-seeking and venting as the endogenous mediators, and the four subscales of the PAI-BOR as the endogenous output variables. We began from a fully-saturated model which included all the predicted paths and iteratively stripped away nonsignificant paths, until we were left with a parsimonious model which showed an acceptable fit to the data – χ²(13) = 22.60, p = 0.047, CFI = 0.99, adj.GFI = 0.99, RMSEA = 0.042 [95% CI: 0.005 − 0.070, p = 0.64]. As illustrated in Fig. 1, attachment anxiety (but not attachment avoidance) was a positive predictor of reassurance-seeking [β = 0.41, z = 9.23, p < 0.001] and venting [β = 0.31, z = 6.79, p < 0.001], and had direct positive effects on all the PAI-BOR subscales [Affective instability: β = 0.25, z = 5.64, p < 0.001; Identity problems: β = 0.41, z = 9.99, p < 0.001; Negative relationships: β = 0.21, z = 4.65, p < 0.001; Self-harm: β = 0.09, z = 2.03, p = 0.042]. Venting, in turn, positively predicted Affective instability [β = 0.38, z = 8.42, p < 0.001], Identity problems [β = 0.25, z = 5.97, p < 0.001], Negative relationships [β = 0.30, z = 6.54, p < 0.001] and Self-harm [β = 0.25, z = 5.34, p < 0.001], whereas reassurance-seeking negatively predicted only Affective instability [β = − 0.11, z = − 3.16, p = 0.002]. Finally, education was negatively associated with all PAI-BOR measures [Affective instability: β = − 0.18, z = − 4.49, p < 0.001; Identity problems: β = − 0.17, z = − 4.39, p < 0.001; Negative relationships: β = − 0.16, z = − 3.83, p < 0.001; Self-harm: β = − 0.21, z = − 4.69, p < 0.001].

Fig. 1.

Model of path analysis (numbers represent standardized coefficients)

Importantly for the present purposes, five indirect effects reached the significance level (see Table 3 for direct, indirect and total effects]. Specifically, venting mediated the positive effects of Attachment Anxiety on all PAI-BOR subscales [Affective instability: β = 0.12, z = 5.28, p < 0.001; Identity problems: β = 0.07, z = 4.48, p < 0.001; Negative relationships: β = 0.09, z = 4.70, p < 0.001; Self-harm: β = 0.08, z = 4.19, p < 0.001]. Hence, participants who had higher levels of attachment anxiety were more likely to use venting strategies, which in turn increased their probability of reporting features associated with BP. Reassurance-seeking, on the other hand, mediated the negative effects of Attachment anxiety on Affective instability [β = − 0.04, z = − 2.99, p = 0.003].

Table 3.

Direct, indirect and total effects estimated in the path analysis

Predictor	Mediator	Output	β	z	p
Direct effects
Attachment anxiety	–-	Affective instability	0.27	5.72	< 0.001
Attachment anxiety	–-	Identity problems	0.42	9.87	< 0.001
Attachment anxiety	–-	Negative relationships	0.21	4.70	< 0.001
Attachment anxiety	–-	Self-harm	0.10	2.23	0.026
Indirect effects
Attachment anxiety	Venting	Affective instability	0.12	5.20	< 0.001
Attachment anxiety	Venting	Identity problems	0.07	4.39	< 0.001
Attachment anxiety	Venting	Negative relationships	0.09	4.63	< 0.001
Attachment anxiety	Venting	Self-harm	0.08	4.05	< 0.001
Attachment anxiety	Reassurance-seeking	Affective instability	− 0.06	− 2.81	0.005
Total effects
Attachment anxiety	–-	Affective instability	0.33	7.26	< 0.001
Attachment anxiety	–-	Identity problems	0.50	11.83	< 0.001
Attachment anxiety	–-	Negative relationships	0.31	6.72	< 0.001
Attachment anxiety	–-	Self-harm	0.18	3.90	< 0.001

Discussion

Attachment styles play a crucial role in understanding emotional dysregulation in individuals with borderline personality (BP) traits. This study specifically examined the relationship between attachment and emotional regulation within interpersonal interactions. We hypothesized that attachment, which shapes representations of the self and others, may contribute to maladaptive behaviours aimed at regulating emotions in social contexts (interpersonal emotion regulation, IER). These maladaptive behaviours could, in turn, intensify the manifestation of BP features. To test this hypothesis, we explored whether difficulties in IER mediate the relationship between attachment insecurity (attachment anxiety and attachment avoidance) and core BP features, including affective instability, identity disturbances, negative relationships, and self-harm.

Consistent with previous literature [58, 84], our findings confirm a strong association between attachment anxiety and BP, with positive correlations observed between attachment anxiety and all dimensions of BP features. In contrast, attachment avoidance showed no significant correlation with BP features, except for a negative association with the negative relationship domain. This finding aligns with previous research [21, 31] and is partially consistent with meta-analytic evidence suggesting a higher prevalence of anxious attachment in individuals with BPD, while also indicating a positive—though less consistent—association with attachment avoidance [84]. This suggests that attachment anxiety plays a more central role in the manifestation of BP features, particularly in the domain of negative relationships. Conversely, attachment avoidance appears to offer some protective effect in this domain,however, this interpretation should be made cautiously, as self-report measures may underestimate interpersonal difficulties in individuals with avoidant attachment [29].

In this study, examining IER as a mediating factor between attachment orientation and BP features provided valuable insights into the mechanisms through which attachment-related emotion regulation styles contribute to relational difficulties and the overall expression of BP traits. In this regard, our findings reveal distinct patterns in the use of IER to regulate emotions based on attachment orientations. Attachment anxiety was associated with higher levels of maladaptive reliance on others for emotional regulation. These results are consistent with previous research demonstrating a relationship between attachment orientation and tendencies in using IER strategies [37, 47, 64], highlighting a clear preference for relationally based IER strategies among individuals with attachment anxiety. Such excessive dependence on others for emotional regulation corresponds to a maladaptive pattern observed not only in BP [28, 61] but also in other conditions involving emotional distress, including depression [28, 68, 69], general psychopathological symptoms [38, 68, 69], eating disorders [25], and increased risk of suicidality [22]. In our view, this excessive reliance on others for emotional regulation, which is observable across multiple psychopathological conditions, may reflect an underlying inability to access or effectively utilize voluntary and adaptive emotion regulation strategies. Consistent with this interpretation, there is broad consensus that, in BPD, the activation of attachment systems within a traumatic interpersonal environment can impair mentalization, preventing individuals from effectively reflecting on their own and others’ mental states [8]. Although the present study did not directly assess mentalization, our findings may indirectly reflect its role, particularly individuals with deficits in mentalization often struggle with reflective thinking and adaptive self-regulation, leading them to externalize their distress in search of immediate relief from others. At the same time, difficulties in representing others’ mental states can distort perceptions of others’ regulatory intentions and hinder the proper interpretation of interpersonal feedback, which could otherwise help prevent the negative consequences of excessive emotional demands in relationships. Thus, this breakdown in mentalization processes may perpetuates a destructive, self-perpetuating cycle of relational difficulties and emotional dysregulation in BPD. Future studies would benefit from directly assessing mentalization capacities alongside interpersonal emotion regulation and attachment orientations, to more precisely identify how deficits in reflective functioning contribute to the development and maintenance of BP features.

Among the IER strategies examined in this study, venting emerged as the most significant predictor of BP, showing a positive correlation with all domains of BP features. Moreover, venting was found to mediate the association between attachment anxiety and all BP features, suggesting that individuals with high attachment anxiety may rely on venting as a means of emotion regulation, which in turn exacerbates BP traits. Venting typically involves the uncontrolled expression of negative emotions such as anger, frustration, or sadness. In this sense, it can be viewed as a failure of mentalization [87]. The maladaptive nature of venting can be understood through the cognitive neo-association theory [10], which posits that negative emotions automatically activate related thoughts, memories, motor reactions, and physiological responses. Consequently, expressing negative emotions through venting may prolong distress by keeping these emotions active in memory, reinforcing negative moods rather than alleviating them [16, 17]. This escalation not only leads to more negative relationships but also contributes to greater affective instability, identity disturbances, and self-harm, contributing to the vicious cycle described above.

As expected, reassurance-seeking was positively and significantly associated with attachment anxiety, as well as with all domains of BP features. These findings suggest that individuals with high attachment anxiety may engage in excessive reassurance-seeking as a means of emotion regulation, aligning with previous research linking reassurance-seeking to attachment concerns, particularly fears of rejection or abandonment [82], as well as perceived threats to the attachment bond [23]. Furthermore, our data confirm previous evidence indicating that an excessive use of reassurance-seeking strategies may exacerbated BP symptoms [28, 65, 66]. Regarding the indirect effects, while venting consistently mediated the relationship between attachment anxiety and BP features, the mediating role of reassurance-seeking was more limited. In the present study, reassurance-seeking showed a small but significant mediating effect only for the symptomatic domain of affective instability, with higher levels linked to reduced symptoms, indicating a potential protective role. This aligns with the view that some forms of IER may enhance social support and buffer against psychological distress [37, 62]. At the same time, this finding should be considered alongside evidence that excessive reassurance-seeking, particularly under conditions of distress, can contribute to rejection, conflict, and abandonment, thereby exacerbating interpersonal difficulties [32, 51, 52]. Moreover, contextual factors, including the perceived efficacy of IER strategies and the willingness of partners to provide support, may critically influence the effectiveness of reassurance-seeking [48]. These considerations make it difficult to draw definitive conclusions about its adaptive nature. Thus, reassurance-seeking can be seen as a compensatory behaviour aimed at restoring a sense of security. Yet, its outcomes appear contingent on multiple relational and contextual factors that future research should further investigate.

Regarding attachment avoidance, the present study suggests that it does not involve the same reliance on others for emotion regulation as attachment anxiety. This aligns with existing research indicating that individuals with attachment avoidance tend to favour intrapersonal, suppression-based emotion regulation strategies [30, 67, 70]. This evidence, combined with the present study’s finding of fewer negative relationships associated with attachment avoidance scores, supports the hypothesis that, while suppression is generally linked to poorer mental health outcomes [2], it may serve a functional role in preserving interpersonal functioning for individuals with BP and attachment avoidance. Specifically, suppression-based emotion regulation strategies may temporarily reduce emotional overwhelm in interpersonal situations, helping to maintain relational stability by preventing emotional outbursts [60]. This highlights the nuanced role of emotion regulation strategies in the interpersonal functioning of individuals with BP, suggesting that attachment avoidance may protect against some relational challenges, albeit at the cost of emotional suppression.

The findings of the present study should be interpreted in light of several limitations. First, while our community sample was reasonably large, it consisted of non-clinical participants. Moreover, although participants were recruited from the general community, no formal assessment of psychiatric status or mental health history was conducted. Therefore, it is not possible to determine whether the sample was entirely non-clinical, which may limit the generalizability of the findings. Future research focusing on clinical samples of individuals affected by BPD may provide a clearer understanding of the relationship between BP, attachment orientations, and IER difficulties.

Second, this study relied exclusively on self-report measures. In terms of attachment, the use of self-report may introduce bias, as avoidantly attached individuals may under-report emotional distress, while anxiously attached individuals may over-report it [29]. This could distort the way participants report affective and relational difficulties. This should be specifically further elaborated, especially for the avoidant subjects, in which interpersonal problems and BP features could be under-reported in the current study. Future studies should use different assessment perspectives to overcome this limitation. Regarding IER, future studies could benefit from exploring additional forms of IER not captured by the DIRE questionnaire, as well as examining its expression in real-life interpersonal interactions. Lastly, although the mediation models were statistically significant, the cross-sectional design of our study limits the ability to draw causal inferences. Longitudinal studies involving clinical samples are necessary to confirm the hypothesis regarding the interplay between attachment and IER in the onset, maintenance, duration, and recurrence of BPD. Finally, the sample is mostly composed of women (70%), and this may limit the generalizability of the results.

Conclusions and clinical remarks

Given the challenges associated with modifying attachment patterns, which persist from childhood into adulthood (Bowlby, 1988), exploring the mediating role of other variables in the relationship between attachment and problematic personality traits may provide more feasible avenues for clinical intervention. The findings of the present study provided a deeper understanding of the psychological dynamics linking anxious attachment, difficulties in IER, and BP features. These insights have significant implications for clinical practice, particularly in the treatment of BP patients with anxious attachment, a subgroup that, according to the literature [1, 84], is most prevalent among individuals with BPD.

Traditional psychological interventions aimed at improving emotion regulation skills often involve psychoeducation and training in adaptive strategies such as reappraisal, acceptance, and problem-solving [9]. These interventions could be expanded to incorporate interpersonal aspects of regulation, fostering awareness of IER, including its relative inefficacy in reducing emotional arousal and its potential negative impact on relationships [66]. However, while educating individuals on balanced and adaptive emotion management strategies can be beneficial, psychological interventions for BP patients with anxious attachment should primarily focus on breaking the cycle of relational difficulties and emotional dysregulation identified in the present study.

In this regard, another category of psychological interventions targeting emotion regulation emphasizes affect-focused, experiential treatments aimed at dismantling dysregulative mechanisms and enhancing tolerance for negative emotions [50, 65]. Techniques based on emotion recognition and expression help individuals develop a more nuanced understanding of their emotional experiences, allowing them to differentiate between affective states rather than feeling overwhelmed or emotionally diffuse [36, 42, 43]. By fostering a deeper awareness of both one’s own and others’ emotions, these approaches strengthen mentalization providing the foundation for adaptive self-regulation, reducing excessive reliance on external sources for emotional regulation.

Authors’ contributions

IM conceptualized the study, designed the research methodology, and drafted the initial manuscript (sections “Introduction” and “Discussion”); PS performed the statistical analyses, interpreted the result, and drafted the initial manuscript (section “Results”); GG reviewed and revised the manuscript for intellectual content; TR collected and organized the data, drafted the initial manuscript (section “Method”); AG reviewed and revised the manuscript for intellectual content. All authors contributed to the final editing of the manuscript.

Funding

The study did not receive external funding, but institutional support was provided by Universitas Mercatorum.

Data availability

The datasets generated during the current study are available from the corresponding author upon reasonable request.

Declarations

Ethics approval and consent to participate

Ethics approval for this study was obtained from the Ethics Committee for Psychological Research at University of Padua [protocol 2019–035], ensuring compliance with ethical guidelines for research involving human participants. All participants provided written informed consent prior to their participation in the study, in accordance with the Declaration of Helsinki. Participants were informed about the study’s purpose, their right to withdraw at any time, and the confidentiality of their responses.

Consent for publication

All participants provided written informed consent for publication, ensuring they understood that their anonymized data might be included in scientific reports, articles, or presentations.

Competing interests

The authors declare no competing interests.