Borderline personality disorder (BPD) is a serious mental health problem characterized by instability in interpersonal functioning, identity, cognition, and emotions, and impulsive and self-damaging behaviours (American Psychiatric Association 2000). Persons with BPD have exceedingly high prevalence rates of suicide attempts (75%) and suicide completion (10%) (Frances et al. 1986), as well as self-injury (69–80%) (Clarkin et al. 1983; Cowdry et al. 1985; Gunderson 1984; Grove and Tellegen 1991; Stone 1993). Many of the severe behavioural problems seen among persons with BPD have been characterized as attempts to avoid or escape from overwhelming emotions (Linehan 1993a, b; Chapman et al. 2005). The aim of this paper is to review research and theory on emotions, experiential avoidance and distress tolerance in relation to BPD, and to discuss clinical and research implications.

Treatments for Borderline Personality Disorder

Several models of treatment for BPD exist, and at least a few of these models have demonstrated empirical support. The concepts of experiential avoidance, emotion regulation, and distress tolerance are perhaps most strongly emphasized within DBT; thus, the majority of this paper will focus on DBT-related concepts. Alternative treatment approaches include Mentalization-Based Treatment (MBT; Bateman and Fonagy 1999), Schema-Focused Therapy (SFT; Young 1994), and Transference-Focused Psychotherapy (TFP; Clarkin et al. 2007). MBT is based on the theory that one of the most important targets in treatment is mentalization, or the ability of the patient with BPD to be aware that thoughts and feelings are related to behaviors (both for oneself and for others). In contrast, SFT is a cognitively-oriented therapy that poses that BPD results from dysfunctional cognitive schemas spawned by early childhood experiences (e.g., neglect, abuse, lack of love, care, or nurturing). As a result, SFT consists of interventions that aim to modify dysfunctional cognitions as well as an intense therapeutic relationship designed to correct for the gaps in the individual’s early experiences with parents and caregivers. Finally, TFP is based on the theory that BPD is characterized, in part, by a rigid use of “splitting” as a defense mechanism. Essentially, the individual’s representations of him or herself and of others are split into “good” and “bad”, and the focus in therapy is on examining transference responses that occur in the context of the therapeutic relationship (among other foci, which given space limitations, cannot be discussed here). MBT (Bateman and Fonagy 1999), SFT (Giesen-Bloo et al. 2006) and TFP (Clarkin et al. 2007) each have had one, well-controlled randomized clinical trial indicating the superiority of these treatments when compared to various control therapies (largely including active treatments themselves). It is noteworthy that, across each of these treatment models, there is an emphasis on emotions and on the therapeutic relationship.

Linehan’s Biosocial Theory of Borderline Personality Disorder

According to Linehan’s biosocial theory (1993a, b), the theory underlying Dialectical Behavior Therapy, BPD results from the transaction of a biologically-based vulnerability to emotions with an invalidating rearing environment. We focus on the biosocial theory here because it has formed the foundation of Dialectical Behavior Therapy (DBT) (for reviews, see Lieb et al. 2004; Robins and Chapman 2004). Within Linehan (1993a, b) framework, the key environmental factor is the invalidating environment, characterized in part by punishment and dismissive or criticizing responses to the emotionally vulnerable child. The invalidating environment also involves an oversimplification of the ease of problem solving or coping, as well as the intermittent reinforcement of extreme emotional displays (Linehan 1993a, b). Vulnerability to emotions, called emotion vulnerability, is the key biological factor—a temperament-based disposition that places the individual at risk of developing BPD in the context of an invalidating environment.

Within this model, the invalidating environment exacerbates the child’s existing vulnerability to emotions, and the child’s vulnerability to emotions sets the occasion for invalidating responses on the part of caregivers (Linehan 1993a, b). Additionally, the invalidating environment does not teach the individual how to regulate or manage his or her emotions. As a result, people with BPD often lack the skills needed to regulate intense emotions, and so they resort to a variety of problematic behaviors to escape or avoid their emotions (e.g., self-harm, suicide attempts, drug use).

The Construct of Experiential Avoidance

Experiential avoidance (EA) is the general term that describes behavior that functions to avoid or escape from unwanted experiences (Hayes et al. 1996). EA is a broad category that includes behaviors that function to avoid or escape from thoughts, emotions, somatic/bodily sensations, or situations. Behaviors that fall within this category might include (but are not limited to) suppressing the experience or expression of emotions, suppressing thoughts, avoiding situations, engaging in distracting activities to avoid thoughts or emotions, and a variety of other behaviors with similar functions (e.g., alcohol or drug use, self-harm, binge eating, suicide attempts). As BPD is conceptualized as an emotion regulation disorder (Linehan 1993a, b), we focus primarily on EA with regard to emotional experiences.

It should be noted that there are some limitations associated with the construct of experiential avoidance. Although Hayes and colleagues put forth this construct to describe behavior that functions to avoid or escape from internal experiences, EA has not always been examined as a functional behavioral response class. Instead, various measures of EA (e.g., the Acceptance and Action Questionnaire; AAQ; Hayes et al. 2004) and related constructs have broadened EA beyond its functional-contextual roots. In the literature, concepts such as “willingness” to experience emotions, and even “emotion regulation” have been framed as aspects of EA. As a result, it is difficult to determine where EA begins and other concepts end, as illustrated later in this paper when we discuss the difference between EA and emotion regulation.

Evidence for Experiential Avoidance in BPD

Several studies of general psychiatric samples have suggested that BPD features are associated with EA. In terms of coping, one study of psychiatric inpatients found that persons with a diagnosis of BPD scored lower on a measure of social support seeking and higher on a measure of avoidance coping, compared with non-BPD participants. The severity of BPD symptoms was also positively associated with avoidance coping and negatively associated with social support seeking. With a sample of incarcerated women, Chapman and colleagues found a positive association of BPD features with thought suppression, EA, and avoidance coping (Chapman et al. 2005). Furthermore, another study found that BPD scores on the Millon Clinical Multiaxial Inventory (MCMI-III) were moderately positively associated with avoidant coping strategies, including denial, self-distraction, behavioral disengagement, and alcohol/drug use (Vollrath et al. 1998).

A couple of studies of substance-abusing individuals have suggested that the presence of BPD is associated with EA. In one study, substance abusers with BPD were more likely to report the use of avoidance/escape coping strategies, compared with substance abusers who did not have BPD (Kruedelbach et al. 1993). Similarly, in a sample of incarcerated females, Chapman and Cellucci (2007) found that substance-dependent individuals with BPD scored higher on measures of EA, compared with substance-dependent individuals who did not have a diagnosis of BPD.

The clinical literature on BPD has also indicated that individuals with this disorder have high prevalence rates of clinical problems that involve EA as a prominent associated feature. For instance, persons with BPD have high rates of dissociative behavior (Linehan 1993a, b; Wagner and Linehan 1995), bulimic behavior (Paxton and Diggens 1997), and substance abuse (Grilo et al. 1997; Malow et al. 1989). Therefore, several lines of research have suggested that BPD is generally associated with heightened levels of EA.

Mechanisms Underlying Experiential Avoidance in BPD

Pinpointing the mechanisms underlying EA among people with BPD has the potential to facilitate effective interventions. If many of the self-destructive behaviors that are so prevalent among persons with BPD fall within the category of EA, understanding why people with BPD engage in EA might shed light on ways to develop or refine treatment interventions. Chapman et al. (2006) have recently proposed that several key factors may increase the likelihood that an individual will engage in EA, including (a) heightened intensity of emotional responses, (b) the presence of particular types of emotional responses, such as aversive, self-focused emotions (e.g., shame and guilt), (c) deficits in skills required to regulate emotions, and (d) a low tolerance for emotional experiences, or low distress tolerance. According to the biosocial theory, individuals with BPD would appear to have heightened levels of each of these characteristics. One factor that we would add to this list includes adverse life events, given the high prevalence of past trauma and severe psychosocial stressors observed among persons with BPD.

Adverse Life Events and Trauma

Chaotic, stressful, and adverse events are common among persons with BPD and may be related to EA. We have clinically observed that persons with BPD experience an inordinate number of stressful life events on a regular basis. Indeed, Linehan (1993a, b) coined the term unrelenting crisis to describe this phenomenon. Stressful life events or hassles might set the occasion for EA, if persons with BPD are prone to the use of avoidance or escape strategies. As mentioned, studies have found that BPD is associated with the use of avoidance strategies to cope with stressors (Chapman et al. 2005).

Aside from stressful events and hassles, persons with BPD have a high prevalence rate of experiences related to trauma. For instance, persons with BPD have a high prevalence rate of past childhood sexual abuse (approximately 50%; Silk et al. 2005), and posttraumatic stress disorder (PTSD) is common among people with BPD (Lieb et al. 2004; Zanarini et al. 2004). As one of the core features of PTSD is avoidance of experiences related to past traumatic events (APA 2000), the experience of traumatic events and the co-occurrence of PTSD may underlie avoidant tendencies among certain people with BPD. On the other hand, people with BPD may already have the tendency to cope with stressful events through EA, even prior to the experience of trauma. In turn, this tendency could place individuals with BPD at risk of developing serious PTSD. Along these lines, some research has suggested that people who have BPD may be more likely to develop PTSD after experiencing a trauma, compared with persons who do not have BPD (Axelrod et al. 2005).

Emotion Vulnerability in BPD

Emotion vulnerability is another possible mechanism underlying EA among persons with BPD. Emotion vulnerability, at least to distressing emotions, would create demands on the individual’s emotion regulatory system, increasing both the need to regulate emotions and the difficulty associated with doing so. If people with BPD are emotionally vulnerable, they might have difficulty managing their emotions and be even more motivated to avoid or escape their emotions, compared with individuals who do not have BPD.

Emotion Sensitivity

Within the Linehan (1993a, b) model, one component of emotion vulnerability is emotion sensitivity, or a low threshold for emotional responding. According to the biosocial theory, it does not take an intense stimulus to elicit an emotional reaction among people with BPD. Persons with BPD tend to respond to low-threshold emotional events to which people with lower levels of emotion sensitivity would not respond. Sensitivity in terms of distressing emotions in particular might partly account for the tendency of persons with BPD to engage in EA. If individuals with BPD experience distressing emotions frequently (because they emotionally respond to many relatively low-threshold events), they may simply have more opportunities to engage in avoidance or escape behaviors. Indeed, an emerging line of research findings has suggested that, when people are emotionally distressed, they tend to focus their coping resources on eliminating distress (Muraven et al. 1998; Tice et al. 2001).

Findings from some studies have also indicated that the resources involved in inhibiting impulses (e.g., impulses to engage in maladaptive escape or avoidance behaviors) may be limited. Just as lifting heavy weights is more difficult after completing seventy repetitions, inhibiting impulses is more difficult after people have already sustained coping efforts for a period of time (Muraven et al. 1998). Due to a high frequency of negative emotions, persons with BPD may be constantly attempting to regulate distress, thus plundering their precious coping resources, and making it likely that they will resort to problematic strategies to escape or avoid their emotions.

There is preliminary support for the presence of heightened emotion sensitivity among persons with BPD. Lynch et al. (2006) compared individuals with BPD (n = 20) to non-BPD controls (n = 20) in terms of their accuracy in identifying emotional facial expressions. Participants completed the Multi-morph Facial Affect Recognition Task (Blair et al. 2001). For this task, participants view photographs of faces as they slowly morph from a neutral facial expression to a strong emotional expression. As facial expressions morphed from neutral to maximum intensity, participants with BPD correctly identified emotions at an earlier stage, compared with non-BPD, healthy controls. Moreover, participants with BPD were more sensitive than controls regardless of whether the expression indicated a positive (e.g., happy) or negative (e.g., fear, sadness) emotion. These findings suggest that individuals with BPD may be especially sensitive to particular forms of interpersonal emotional stimuli; namely, emotional facial expressions.

Persons with BPD also appear particularly prone to the experience of unpleasant, self-focused emotions, such as shame. Several researchers (e.g., Crowe 2004; Linehan 1993a, b) view shame as being central to the dysregulation in BPD. In a recent study, female patients with BPD report higher levels of shame than do healthy females (Chan et al. 2005). Individuals with BPD also demonstrated higher proneness to shame than other clinical populations, including individuals with social phobias (Rüsch et al. 2007). Even compared to individuals with other personality disorders (e.g., Avoidant or Obsessive Compulsive), persons with BPD endorsed more items linked to cognitive schemas related to shame and defectiveness (Jovev and Jackson 2004). Shame and related self-focused emotions that lead to an unpleasant sense of self-awareness might be particularly potent triggers of behaviors related to EA (e.g., suicide attempts; Baumeister 1990; self-harm; Chapman et al. 2006).

Emotion Reactivity

The second component of emotion vulnerability is emotional reactivity, or intense responses to emotional stimuli. Individuals with heightened levels of emotional intensity may struggle in regulating their emotions, partly because they must regulate greater levels of arousal (Flett et al. 1996). One study found that greater emotional arousal is associated with greater difficulty regulating emotions (Eisenberg et al. 1998). Studies of both clinical and non-clinical samples have reported significant, positive associations of EA with emotional intensity/reactivity (Gratz et al. 2001; Lynch et al. 2006) in both clinical and non-clinical samples. Having intense emotional responses likely makes persons with BPD vulnerable to the use of EA strategies.

Findings of studies that have examined subjective self-reports of emotions and related traits have supported the theory that persons with BPD are emotionally reactive. Persons with BPD report greater levels of personality traits related to negative affect (Farmer and Nelson-Gray 1995) and display heightened responses to negative emotional stimuli (Levine et al. 1997), compared to non-BPD controls. Additionally, field studies of negative emotions in daily life have indicated that persons with BPD tend to experience more frequent and intense emotional distress (called “aversive tension”), compared with healthy controls (Stiglmayr et al. 2001, 2005).

Despite these findings, the findings regarding whether BPD is associated with increased physiological arousal are inconclusive. In two studies that examined physiological measures of emotional responding, persons with BPD did not demonstrate greater emotional responding to unpleasant pictures, compared with normal controls and persons with avoidant personality disorder (Herpertz et al. 1999, 2000). These studies, however, utilized standardized distressing pictures that may not capture the unique factors that trigger emotional distress among persons with BPD (e.g., rejection, abandonment; Stiglmayr et al. 2005). Additionally, the researchers did not control for dissociation during exposure to the unpleasant pictures, a feature related to BPD that may attenuate emotional responses. In a study of the startle response, individuals with BPD demonstrated higher arousal in response to the startle stimuli (Ebner-Priemer et al. 2005), compared with non-BPD controls. Higher levels of dissociation, however, were associated with lower physiological arousal, suggesting that dissociation may attenuate psychophysiological responses.

Another limitation of the research on psychophysiology and BPD has to do with the psychophysiology measures themselves. Specifically, limitations in the selection of psychophysiology measures and the complex interactions among measures of sympathetic and parasympathetic arousal obscure the findings. Studies have largely relied on indicators of sympathetic arousal. An interaction of both the sympathetic and parasympathetic nervous system influences determine cardiac patterns of arousal (Beauchaine 2001); thus, studies must examine both sympathetic and parasympathetic activation. Findings from recent studies have indicated that measures of cardiac vagal tone (a suggested index of parasympathetic activation) differentiate clinical from non-clinical populations (Beauchaine 2001). Further research is needed to clarify whether BPD is actually characterized by intense emotional responding. Thus far, findings suggest a disconnect between subjective reports of emotional responding and psychophysiological data on emotional responding in BPD.

Slow Return to Baseline

The third component of emotion vulnerability involves slowness in the individual’s return to baseline levels of emotional arousal, or slow return to baseline. To our knowledge, no published study has addressed this aspect of emotion vulnerability among persons with BPD. It is possible that emotional reactivity is intricately intertwined with heightened levels of emotion reactivity among persons with BPD. On a very basic level, we might expect stronger emotions to take longer to return to baseline levels. As a result, the individual with BPD is left dealing with distressing emotions for a lengthy period, which might increase the likelihood of attempts to avoid or escape emotions.

It is not clear, however, whether persons with BPD show slower return to baseline levels of subjective or psychophysiological emotional arousal. The issue of return to physiological baseline is particularly complex, depending on several factors, including movement, respiration rate, additional triggers for emotional arousal, attempts to regulate or manage emotions, among other factors. For example, certain emotion regulation strategies (such as suppressing expression of emotions) have been associated with heightened parasympathetic arousal (Butler et al. 2006). Similarly, the issue of returning to baseline subjective emotional experiences is also complex and may depend, in part, on conscious attempts to regulate or manage emotions.

Problems with Emotion Regulation in BPD

Another factor that increases the likelihood of EA among persons with BPD is emotion dysregulation, or difficulty regulating emotions. According to Gross (1998), emotion regulation is the process by which individuals influence which emotions they have, when they have them, and how they experience or express these emotions. As mentioned, it appears that the inability to effectively regulate emotions is one of the central problems associated with BPD.

Within this model, the regulation of emotions may involve several different strategies, some of which modify the antecedents of an emotional response, while other strategies involve directly modifying the emotional response itself (Gross and John 2003). Examples of antecedent-oriented strategies include (a) avoidance or modification of situational factors that elicit emotions, (b) modifying cognitive appraisals of emotionally evocative situations, and (c) deploying attentional focus away from emotionally evocative events. Strategies focused on modifying emotional responses may include suppressing an emotional experience, inhibiting the expression of an emotion, or cognitive, behavioral, or physiological activities that modify an emotional experience once it has begun.

Deficits in emotion regulation among persons with BPD specifically involve difficulty employing response-focused emotion regulation strategies (problems up- or down-regulating emotional experiences once they have begun), difficulty deploying attention away from emotionally evocative stimuli, and maladaptive attempts to control intense emotions (Linehan et al. 2006). We have clinically observed that persons with BPD have marked difficulties with an additional aspect of emotion regulation; namely, difficulty inhibiting mood-dependent behaviors (Gottman and Katz 1989). Indeed, impulsive, potentially self-damaging behaviors are a defining feature of BPD (APA 2000). Behaviors such as substance abuse, risky sexual activity, and binge eating, often increase positive emotions (e.g., excitement, euphoria) or decrease negative emotions. Interestingly, Barlow et al. (2004) have recently proposed that inhibiting emotion-consistent behaviors is a central component of treatments for disorders characterized by emotional dysregulation.

We propose that deficits in the individual’s ability to devise or implement effective emotion regulation strategies increase the likelihood of EA among persons with BPD. As a clinical example of this phenomenon, “Mandy’s” boyfriend just broke up with her, and she feels abandoned, sad, angry, and ashamed. If Mandy cannot devise a way to manage these emotions, she might employ strategies that are quick and readily available, and that help her avoid or escape her feelings, at least temporarily. Some of these strategies might involve suppressing thoughts about the break-up, inhibiting her expression of sadness (acting as if everything is OK), suppressing the experience of her emotions, denying that the break up even happened, or engaging in self-harm or drug use to escape her emotions (or thoughts).

Even if Mandy can devise a more adaptive way to cope, she may resort to these behaviors, if these behaviors work more quickly than do other strategies, or if she has difficulty implementing more adaptive coping strategies (Chapman et al. 2006). For instance, she may be too distressed to think clearly enough to engage in antecedent reappraisal, or she may not have the time or opportunity to use strategies that directly modify the emotion, such as breathing exercises or physical exercise.

Another important factor to consider is Mandy’s self-efficacy, or belief that she can successfully engage in adaptive coping behaviours that will effectively reduce her emotional arousal. A relation between self-efficacy and pain tolerance has been demonstrated in a number of studies (Bandura et al. 1987; Litt 1988; Vallis and Bucher 1986) and the importance of self-efficacy may extend to coping with aversive emotional or psychological experiences as well. If Mary does not have confidence in her ability to carry out direct coping strategies, then she may be more likely to simply escape or avoid her emotional experience.

Distress and Frustration Intolerance in BPD

One missing link, however, in the association between emotion vulnerability, emotion dysregulation, and EA, involves the individual’s ability to tolerate distress. Even if, for example, Mandy has abysmal emotion regulation skills and is extremely emotionally reactive, she may not avoid her emotions if she can tolerate high levels of distress for long periods of time. Distress tolerance has been defined as the capacity to experience and to withstand negative psychological states (Simmons and Gaher 2005). Recent research suggests that one’s ability to tolerate both physical and psychological distress is a crucial predictor of emotional adaptation to aversive events (Brown et al. 2002; Zvolensky et al. 2001). Findings from some studies have suggested that persons with BPD may experience lower tolerance for psychological distress (Lejuez et al. 2004), compared with non-BPD individuals. In contrast, persons with BPD may actually have heightened levels of tolerance for physical pain (Bohus et al. 2000; McCown et al. 1993). If persons with BPD have low distress tolerance, they would likely feel a strong desire to eliminate unpleasant emotions as quickly as possible.

Chapman et al. (2006) have suggested that the degree to which persons experience their emotional arousal as unpleasant strongly influences their ability to tolerate distress. Evidence indeed suggests that individuals with BPD may subjectively experience negative emotions as being more aversive and troubling than do non-BPD controls (Kelly et al. 2000; Stanley and Wilson 2006; Zeigler-Hill and Abraham 2006). Additionally, individuals with BPD report greater fear of emotions (Yen et al. 2002) and have demonstrated an unwillingness to experience emotional distress in order to pursue a goal (Gratz et al. 2006).

Persons with BPD may have difficulty tolerating distress, in part, because they experience their emotions as particularly aversive. The tendency of persons with BPD to self-report high levels of subjective negative emotions, in the absence of findings indicating heightened psychophysiological responding, may indicate an acute aversion to emotions. Similarly, one study found that participants high in EA reported greater levels of anxiety and distress in response to a biological challenge, compared with persons who were low in EA, but the high-EA persons did not demonstrate greater physiological arousal (Feldner et al. 2002). One study found that patients with comorbid major depressive disorder (MDD) and BPD evidenced more depressive symptoms than patients with only MDD on subjective self-report measures, but not on a more objective, clinician-rated measure (Stanley and Wilson 2006). This difference was significant even after controlling for clinician-rated severity. Therefore, if persons with BPD experience their emotions as unpleasant, and therefore have difficulty tolerating these emotions, they may resort to EA to escape or avoid emotions.

Within Rational Emotive Cognitive-Behavior Therapy (RECBT), the related concept of frustration tolerance has been applied to BPD (see Ellis 1994). Frustration tolerance is the belief that events, situations, emotional states, and problems should not be as bad, unpleasant, or difficult as they are. Whereas distress tolerance involves the ability to withstand particular psychological states, frustration tolerance has to do with the belief that the psychological states should not be happening or should not be as bad as they are. As a result, within this framework, frustration tolerance may actually undermine distress tolerance. An individual with BPD who believes that a particular emotion (e.g., anger, or anxiety) or problem (e.g., a stressor, or a physical illness of some kind) should not be occurring or should not be as strong as it is might have great difficulty tolerating it.

As an example, when Mandy experienced a recurrence of chronic asthma, her thoughts would often include the following: “Why is this happening again?!” “This can’t be happening again!” “I should be able to cope with this better” “I just can’t take this anymore. I can’t stand it!” This type of thinking pattern is also very similar to rumination (REF), which involves an intense cognitive focus on undesired symptoms or experience. The main difference between rumination and frustration tolerance is that individuals with poor frustration tolerance believe that whatever is happening should not be happening. Anecdotally, we have observed that individuals who have BPD and co-occurring anxiety disorders, such as generalized anxiety disorder, are much more likely to exhibit poor frustration tolerance.

As suggested by Ellis (1994), ironically, poor frustration tolerance can short-circuit the individual’s attempts to improve his or her life. A problem or stressor occurs, and the individual becomes focused on the idea that it should not be occurring, feels distressed, frustrated, and angry, and then takes measures to escape the problem and the associated emotions (experiential avoidance), rather than to solve the problem or re-construe it in a more adaptive manner. Ellis (1994) has suggested that one key intervention in the treatment of BPD (at least within an RECBT model) involves highlighting the self-defeating nature of low frustration tolerance beliefs.

Was it the Chicken or the Egg? The Vicious Cycle of Experiential Avoidance and Emotional Distress in BPD

Paradoxically, it seems that inflexible reliance upon EA may actually create more problems than it solves. Overall, EA is linked to a number of negative outcomes and is associated with psychopathology (Hayes et al. 1996, 2004). Several specific psychiatric disorders are strongly associated with EA, including panic disorder (Craske and Barlow 1993), social phobia, avoidant personality disorder, post-traumatic stress disorder (American Psychiatric Association 1994; Foa and Rothbaum 1998; Walser and Hayes 1998), and obsessive–compulsive disorder. Using experience sampling methodology, EA has also been linked to fewer positive events (such as “met a daily fitness goal” and more negative events, such as “was excluded or left out by my group of friends”) in every day life (Kashdan et al. 2006). EA has also been associated with higher levels of negative affect and lower levels of positive affect (Kashdan et al. 2006), as well as higher emotional reactivity (Sloan 2004). Furthermore, EA following a traumatic event was an even better predictor of poor post-event psychological functioning than the severity of the event, general psychopathology, or functioning before the event (Plumb et al. 2004). Taken together, these findings suggest that consistent engagement in EA behaviours may amplify distress in the long term.

EA also may lead to greater levels of emotional distress among persons with BPD. It is possible that persons with BPD do not have a dispositional vulnerability to emotions, but rather, the way in which they cope with their emotions might produce heightened emotion vulnerability. In one recent study, scores on measures of EA fully mediated the relationship between negative affect reactivity and intensity and BPD features, even after controlling for child abuse (Rosenthal et al. 2005). In another study, thought suppression mediated the relationship between negative affect reactivity and intensity and BPD features (Cheavens et al. 2005). Thought suppression has also been related to the frequency of deliberate self-harm (DSH) among individuals with BPD (Chapman et al. 2005). Together, these findings suggest that EA plays a key role in the emotional distress and maladaptive behaviors observed among persons with BPD.

It is important to note that these correlational findings, by themselves, cannot yield conclusions about a causal influence of EA on distress. Mounting laboratory evidence, however, suggests that EA may indeed increase levels of subjective and physiological distress. For example, suppression of unpleasant or aversive thoughts and sensations appears to actually increase the occurrence of such thoughts in the future, particularly when people are under stress or engaging in a concurrent task that requires effort (Davies and Clark 1998; Macrae et al. 1997; Wegner and Erber 1992) (also see Abramowitz et al. 2001 for a meta-analytic review).

The inhibition of emotional expression appears to have negative effects on psychophysiological arousal and social interactions. In one study, persons instructed to inhibit their emotional expression during happy and sad films demonstrated greater sympathetic arousal, compared with individuals who were not instructed to inhibit expression (Gross and Levenson 1997). Participants who were instructed to inhibit emotional expression during a conversation with a partner experienced increased levels of parasympathetic indicators as well as sympathetic arousal (Butler et al. 2006). Moreover, the conversation partner was less likely to choose to interact with an individual again if that individual had been inhibiting his or her emotional expression during the conversation. In another study, individuals who reported high levels of EA demonstrated lower sympathetic arousal (compared with low-EA individuals) in response to unpleasant stimuli, while simultaneously reporting higher subjective reactivity to such stimuli (Sloan 2004). Together, these findings suggest that the general tendency to engage in experiential avoidance (perhaps chronically) is positively associated with subjective distress, whereas the active suppression of emotions in the laboratory is more consistently associated with heightened physiological responding.

The occasional avoidance of unpleasant internal experiences on its own may be relatively inconsequential. Chronic EA, however, may be particularly detrimental. Distress experienced by persons with BPD increases their use of EA, which in turn increases physiological arousal and subjective distress, and so on. This positive feedback cycle has been conceptualized as the mechanism by which deliberate self-harm is developed and maintained as a coping strategy (Chapman et al. 2005, 2006). According to the Experiential Avoidance Model of self-harm (EAM), the act of escaping or avoiding unpleasant emotions through DSH is reinforced in the short-term by relief from emotional arousal. In the long-term, however, escape or avoidance prevents new learning (i.e., through exposure), causes a “rebound effect,” and actually increases the probability of more frequent or intense negative experiences. These negative experiences then prompt further EA (possibly including DSH), and the cycle is strengthened and maintained.

Additionally, chronically avoiding unwanted experiences short-circuits the type of problem solving efforts that might reduce these experiences in the long-term. If “Mandy” in the example above repeatedly avoided all emotions related to the break-up with her boyfriend, she may not spend time trying to figure out how to cope effectively, prevent future break-ups, improve her skills at selecting boyfriends, or engage in other such problem solving strategies.

Conclusions and Future Research Directions

Our conceptualization of EA among persons with BPD suggests the need for future research in several areas. One direction for future research involves further examinations of whether persons with BPD do indeed demonstrate heightened levels of EA. One of the primary limitations in the research on EA and BPD, and in the research on BPD more generally, is the reliance on non-clinical control groups. It is not surprising that persons with BPD report more EA, greater levels of emotional distress, and poorer distress tolerance, when compared with “healthy” controls. In order to determine whether these are specific and unique characteristics of BPD, studies must compare persons with BPD to persons who fall within other clinical groups.

A second direction for research in this area involves using a multi-method approach to examining EA among persons with BPD. The majority of the research on EA and BPD has relied solely on questionnaire measures of various aspects of EA. Although findings from these studies are certainly illuminating, studies that incorporate behavioral, observational, or other types of methods to measure EA would strengthen the empirical foundation of this research.

Researchers have developed laboratory experimental paradigms used to examine emotion regulation, emotion suppression, and thought suppression among “normal” populations (Gross and Levenson 1997; Wegner 1994). These paradigms, however, have yet to be used in published research on EA or emotion regulation among persons with BPD. Within our lab, we recently used an emotion suppression paradigm to examine the effects of EA in daily life among persons with BPD features. Participants were instructed to observe or suppress their emotions in daily life, using experience sampling methods and personal data assistants (PDAs) to record emotional responses, urges to engage in self-damaging behaviors, and actual engagement in self-damaging behaviors (Chapman et al. in preparation). The findings indicated that, compared with observing emotions, suppressing emotions led to greater levels of negative emotions among controls (who were low in BPD features), but not among persons who were high in BPD features.

Another recent study from our lab involved asking incarcerated females (N = 63) with and without BPD about their emotional experiences prior to and following a recent act of deliberate self-harm. Findings indicated that persons with BPD were more likely to report a shift toward more positive emotions following deliberate self-harm, compared with non-BPD individuals (Chapman and Dixon-Gordon 2007). Future research might investigate differences in the effects of a variety of emotion regulation and EA strategies among persons with BPD, clinical controls, and non-clinical controls.

A third direction for future research involves examining the mediators and moderators of the association of emotion vulnerability with BPD. As suggested by our model, emotion vulnerability in BPD may lead to EA, and EA may exacerbate emotion vulnerability. Future studies are needed to examine whether persons with BPD are actually vulnerable to negative emotions, whether the way in which they respond to negative emotions leads to higher reports of negative emotions, or both. Further research is also needed to examine the association of distress tolerance with BPD, and whether distress tolerance mediates the link between BPD and EA.

A fourth direction for future research involves further clarifying the distinction between emotion regulation and EA. At present, it is difficult to determine where emotion regulation ends and EA begins. One the one hand, EA behaviors are a subset of emotion regulation, focused on avoiding or escaping emotional experiences or situations that occasion these experiences. On the other hand, EA is somewhat broader in focus than is emotion regulation, in that EA includes avoidance or escape from thoughts, somatic sensations (e.g., physical pain), and undesired events. Emotion regulation, in contrast, focuses specifically on the regulation of emotions. Still, within Gross’s (1998) model, the regulation of emotions might involve altering thoughts, avoiding or modifying situations, or altering physiological activities or experiences. Emotion regulation, in this way, might always constitute EA, to some degree, in that regulating emotions involves altering the form or frequency of emotional experiences, thoughts, or situations—factors considered central to EA (Hayes et al. 1996). Perhaps one area of departure between EA and emotion regulation is the possibility that emotion regulation might, at times, involve homeostatic mechanisms of the emotion system that automatically regulate the length or intensity of an emotional response. In contrast, EA (as conceptualized by many researchers) largely involves deliberate actions undertaken to avoid or escape experiences.

The blurry distinction between emotion regulation and EA is somewhat problematic from the standpoint of understanding how to help people with disorders such as BPD. If EA is problematic and maladaptive in certain contexts, and emotion regulation largely involves EA, then teaching people with BPD emotion regulation skills might exacerbate their existing tendencies to avoid or escape emotions. On the other hand, there is strong evidence that treatments that involve an emotion regulation component, such as DBT, are efficacious for BPD (see Robins and Chapman 2004 for a review). Even within the emotion regulation skills taught in DBT, however, there is a balance between acceptance-oriented skills and change-oriented skills. Some skills help the client to step back, observe, and let his or her emotions go (e.g., “observing emotions”); other skills help the client to directly modify the emotional experience once it has begun, or to reduce his or her vulnerability to emotions (Linehan 1993b).

As mentioned, in some contexts, EA is not always maladaptive. With the example of “Mandy”, if she went to work after her boyfriend broke up with her and expressed all of the sadness that she felt, she might have difficulty functioning. If she did not do anything to regulate her intense anger toward her boyfriend, she may have difficulty thinking, concentrating, getting her work done or effectively interacting with her boss. Some of the actions she might take to regulate her anger could involve avoiding temporarily avoiding thoughts about the boyfriend, distracting herself with other activities, or using relaxation strategies to reduce her anger. All of these strategies could be considered EA, to some degree. At the very least, Mandy might need to regulate her behavior in the presence of intense anger, but doing so also constitutes emotion regulation (and possibly EA), as modifying action tendencies is a key emotion regulation strategy (Barlow et al. 2004). Even the use of acceptance-oriented strategies, such as those commonly used in Acceptance and Commitment Therapy (ACT; Hayes et al. 1999), might function to alter the form or frequency of Mandy’s anger. Indeed, in many life contexts, some degree of regulation, management, or even avoidance of emotional experiences is adaptive. The challenge for people who struggle with BPD is to find a way to regulate emotions that brings them closer to life goals that they value. We hope that further theoretical and empirical work on EA and emotion regulation in BPD will help us to enhance and refine treatments that will accomplish this daunting yet critical task.