تمایز عصبی کاهش یافته بین فرآیندهای شناختی و عاطفی خودارجاعی در زنان مبتلا به اختلال شخصیت مرزی

Borderline personality disorder (BPD) is associated with disturbed emotion regulation. Psychotherapeutic interventions using mindfulness elements have shown effectiveness in reducing clinical symptoms, yet little is known about their underlying neurobiology. In this functional magnetic resonance imaging (fMRI) study, 19 female BPD patients and 19 healthy controls were compared during mindful introspection, cognitive self-reflection and a neutral condition. The activation pattern in the right dorsomedial prefrontal cortex (DMPFC) in BPD patients was different from that in healthy subject when directing attention onto their emotions and bodily feelings in contrast to cognitively thinking about themselves. Mindful introspection compared with the neutral condition was associated with higher activations in bilateral motor/pre-motor regions, left inferior frontal gyrus (IFG), and left posterior cingulate cortex (PCC), while cognitive self-reflection activated the right motor and somatosensory cortex, extending into the right supramarginal gyrus (SMG) and superior temporal gyrus (STG) in BPD patients compared with the controls. Results indicate that self-referential cognitive and emotional processes are not clearly differentiated in BPD patients at the neurobiological level. In particular, altered neural mechanism underlying self-referential thinking may be related to some aspects of the typical emotion dysregulation in BPD. Current data support the finding that mindful self-focus attention is effective in regulating amygdala activity in BPD as well as in healthy subjects.

Borderline personality disorder (BPD) is estimated to affect about 3% of the general population (Trull et al., 2010 and Bohus and Kröger, 2011). It is the most common personality disorder, accounting for 10% of all psychiatric outpatients and about 20% of inpatients (Leichsenring et al., 2011). Individuals with a diagnosis of BPD suffer from dysfunctional emotion regulation, poor impulse control, and distorted self-image (Lieb et al., 2004). Difficulties specifically in the domains of self-focused attention and in regulating internal and external experiences play a central role in the disorder (Linehan, 1993a, Linehan, 1993b and Cheavens et al., 2005). Several forms of psychotherapeutic interventions are available for patients with BPD (Binks et al., 2006). Amongst those, Dialectical Behavior Therapy (DBT) has proved efficacious in reducing clinical symptoms in BPD (Linehan, 1993a and Linehan et al., 2006; meta-analysis: Kliem et al., 2010). One main component of successful DBT treatment is the training of mindfulness (e.g., Feliu-Soler et al., 2014). The main goal of mindfulness practice is to reach a mental state in which one is attentive, aware, and accepting (non-judgmental) of the present moment, without becoming over-involved in cognitive or emotional reactions (Kabat-Zinn, 2003). Generally, mindfulness is conceptualized as a meditation technique. Yet, it has also been increasingly implemented in psychotherapy (Hofmann et al., 2010). In this context, a mindfulness approach aims at developing a general attitude to face emotional situations with a focus on the current experience (Bishop et al., 2004). The functional relationship between mindfulness skills and BPD symptoms has been investigated prominently. Evidence suggests that low abilities in mindfulness may account for BPD-specific problems in emotion regulation, interpersonal function, and impulsivity (e.g., Wupperman et al., 2008; Wupperman et al., 2009; Fossati et al., 2011). In a preliminary study examining the mediating effect of mindfulness on BPD symptoms, Wuppermann and colleagues (2013) suggested that typical dysregulated behaviors observed in BPD -- for instance, self-injury, substance abuse, suicide attempts, or physical aggression (American Psychiatric Association, 2000) -- were associated with a low level of mindfulness (Wupperman et al., 2013). The authors assumed a link between mindfulness deficits and BPD symptom severity. However, until now, the question of causality remains unanswered. Mindful self-focused attention has been proposed as an adaptive regulation strategy for BPD patients in dealing with daily stressors. In a laboratory setting, Sauer and Baer (2012) found positive short-term effects of mindful self-focus in patients with BPD, who either were instructed to respond either with mindful self-focused attention or with ruminative self-focused attention during a distress-tolerance task after angry mood induction. The mindfulness group demonstrated more persistent toleration of distress and reported lower levels of anger (Sauer and Baer, 2012). Despite the empirical evidence, little is known about the neurobiological mechanisms underlying the effects of mindful self-focused attention in BPD. In healthy participants, a mindful attitude has been linked to activation patterns in the medial and lateral prefrontal cortex (M/LPFC) (Creswell et al., 2007) as well as in parietal structures associated with attention (Dickenson et al., 2013). A mindfulness-close approach (e.g., affect labeling) has been further accompanied by reduced amygdala activations, suggesting less emotional arousal (Creswell et al., 2007 and Lieberman et al., 2007). Additional support in this context was also provided by our previous study, where healthy subjects performed a self-reference task by making themselves aware of their emotions, bodily feelings, or cognitions (Herwig et al., 2010). In that study, similar to the above-mentioned findings, focusing on current emotions and bodily feelings in the absence of external stimuli was associated with reduced amygdala activity and enhanced activations in the medial and ventrolateral prefrontal cortex (M/VLPFC). This very basic task of a briefly induced period of mindful self-focused attention reduced amygdala activation, which is closely linked to (emotional) arousal. Prefrontal activity was further negatively correlated with trait mindfulness, pointing to a need to use a lower level of resources in high trait-mindful participants. Hence, in the present study, we intended to examine the neurofunctional network activated in BPD patients while applying this basic mindfulness mechanism of introspection or directing attention towards current emotions and bodily feelings, and of cognitive self-reflection. We compared the involved circuits in BPD with those in matched healthy control subjects. Mainly, we were interested in whether the mechanism of mindful self-focused attention would have a comparable regulating effect on amygdala activity and also whether it would involve a similar regulating network of prefrontal areas in patients as that earlier observed in healthy participants (Herwig et al., 2010). In patients with BPD, unpleasant emotions often arise spontaneously without any explicit external trigger and are experienced as internally generated (Linehan, 1993a). For that reason, we aimed at focusing on inner processes, without external stimulation to avoid differential reactions towards (additional) negative external stimuli in BPD. Considering emotional dysregulation and disrupted self-related awareness (Lieb et al., 2004) as core features in BPD, we hypothesized limited regulatory control of the amygdala by prefrontal regions during mindful self-focused attention in patients relative to controls. Furthermore, given the negative correlation of PFC activity with trait mindfulness in healthy participants, we expected increased activations in PFC areas in BPD compared with control participants.