ذهن آگاهی و اجتناب تجربی به عنوان پیش بینی کننده علائم اجتنابی اختلال استرس پس از سانحه شدت

Mindfulness reflects an awareness of present moment experiences through an attitude of acceptance and openness (Bishop et al., 2004 and Cardaciotto et al., 2008). Experiential avoidance, by contrast, refers to attempts to change, alter, or avoid private experiences (e.g., thoughts, feelings, sensations), and it is believed to underlie a number of psychopathologies, including PTSD (Hayes, Wilson, Gifford, Follette, & Strosahl, 1996). We were interested in the ability of mindfulness to predict the variance of PTSD avoidance symptom severity above and beyond experiential avoidance. 378 introductory psychology students were administered self-report measures of PTSD, mindfulness, experiential avoidance, thought suppression, alexithymia, and avoidant coping. Mindfulness, specifically nonjudgment of experiences, accounted for a unique portion of the variance in PTSD avoidance symptoms.

Of the three symptom clusters associated with PTSD, research suggests that avoidance symptoms (criterion C) are the most reliable indicator that an individual may meet full PTSD criteria (see Nemeroff et al., 2006), and they appear to be most predictive of overall PTSD symptom severity (Boeschen et al., 2001, Marshall et al., 2006 and Marx and Sloan, 2005). Criterion C symptoms include efforts to avoid experiences related to the trauma, difficulty recalling the trauma, diminished interest in activity, feelings of detachment, restricted affect, and a feeling that one's future has been foreshortened (American Psychiatric Association, 2000). Avoidance strategies are also thought to underlie several psychopathologies, such as substance abuse and obsessive–compulsive disorder, as well as PTSD. These patterns of behaviors have been given the umbrella term experiential avoidance within the Acceptance and Commitment Therapy (ACT) literature (Hayes, Strosahl, & Wilson, 1999). Experiential avoidance occurs when an individual engages in strategies to blunt, alter, or control distressing private experiences, such as thoughts, emotions, and physiological sensations (Hayes et al., 1996). A reliance on experiential avoidance strategies appears to exacerbate or maintain PTSD symptoms over time (Tull, Gratz, Salters, & Roemer, 2004). Additionally, they may reduce one's flexibility in dealing with situations, negatively impacting quality of life (Kashdan, Barrios, Forsyth, & Steger, 2006). Following exposure to a traumatic event, avoidance behaviors may initially be focused on activities and stimuli that remind the individual of, or are connected to the individual's experience of the trauma; however, these strategies may gradually generalize to non-trauma related stimuli and contribute to the maintenance of posttraumatic symptoms in the long-term (Polusny and Follette, 1995, Rosenthal et al., 2005 and Varra and Follette, 2005. Blackledge (2004) offers three reasons for why experiential avoidance may maintain PTSD symptoms over time: It limits opportunities for positive reinforcement; some types of avoidance behaviors such as substance abuse may increase exposure to aversive experiences; as no new learning occurs, it may maintain verbal rules which continue to limit exposure to real world consequences (e.g., “Being in crowds is dangerous”). As experiential avoidance is a very broad term, we were interested in examining specific avoidance strategies that have an established research base within the PTSD literature. 1.1. Types of experiential avoidance associated with PTSD 1.1.1. Alexithymia The term alexithymia was first introduced by Sifneos (1973) to describe patients exhibiting psychosomatic symptoms who had difficulty identifying and describing emotions. Recent research suggests that alexithymic individuals have difficulty drawing relationships between emotions and physiological sensations (Waller & Scheidt, 2004). Stewart, Zvolensky, and Eifert (2002) suggest that that alexithymia is a form of “emotional constriction” and subset of experiential avoidance. The relationship between alexithymia and PTSD may be bidirectional. On one hand, there is evidence that individuals higher in alexithymia may be more likely to develop PTSD following trauma exposure (Kosten, Krystal, Giller, Frank, & Dan, 1992). Higher levels of alexithymia may also be a consequence of PTSD symptoms. Söndergaard and Theorell (2004) found that alexithymia increased following exposure to trauma in a sample of war refugees assessed at 3-month intervals. Badura (2003) suggests that alexithymia in individuals with PTSD may be better understood as representative of the emotional numbing component of PTSD than as a distinct construct, that individuals with PTSD begin to employ an avoidance-based coping style to deal with reexperiencing and hyperarousal symptoms. Other researchers have found a strong relationship between alexithymia and emotional numbing in individuals with PTSD (Frewen et al., 2008a, Frewen et al., 2008b and Fukunishi et al., 1996). Frewen et al. suggest that trauma disrupts an individual's ability to interpret the relationship between mind and body experiences. 1.1.2. Thought suppression Thought suppression is one of the most widely studied forms of experiential avoidance. There are three consequences associated with thought suppression: (1) an increased likelihood of target thoughts following suppression; (2) a sudden increase in target thoughts following suppression; (3) an increase in intrusive target thoughts during suppression when cognitive demands begin to interfere with attempts at suppression (Wenzlaff & Wegner, 2000). The use of thought suppression appears to predict PTSD symptom severity (Mayou et al., 2002 and Steil and Ehlers, 2000). In what they call the theory of ironic processes, Wenzlaff and Wegner (2000) argue that the continued monitoring for unwanted thoughts interferes with the overarching goal of thought suppression, making unwanted thoughts more salient and thus priming a rebound effect. Shipherd and Beck, 1999 and Shipherd and Beck, 2005 have found that individuals with PTSD exhibited a rebound effect in trauma-related thoughts following a deliberate suppression, but trauma survivors without PTSD did not exhibit a rebound effect, suggesting that the rebound effect may play a role in the maintenance of PTSD symptoms. 1.1.3. Avoidant coping Avoidant coping refers to the tendency to respond to distressing stimuli through distraction, such as through socializing or watching television (Endler & Parker, 1990, 1994). Following trauma, individuals may engage in strategies to avoid stimuli that remind them of the traumatic event (Steil & Ehlers, 2000). Although avoidant coping may be adaptive in the short term in some situations (Chaffin, Wherry, & Dykman, 1997), studies have found that an avoidant coping style is predictive of PTSD symptomatology (e.g., Gil, 2005 and Scarpa et al., 2006). In the Gil study, the researcher had collected his sample of coping styles for another study 2 weeks prior to a terrorist attack and was able to collect a posttrauma measure of coping 1 month after the attack. PTSD was assessed 5 months later. Similar to alexithymia, the results of this research suggest a bidirectional relationship between avoidant coping and PTSD: Avoidant coping may create a vulnerability to developing PTSD following trauma exposure, and trauma survivors may begin applying avoidant coping strategies following trauma. 1.2. Mindfulness The concept of mindfulness was originally inspired by 2500 year-old Buddhist meditation practices. Much of the recent interest in mindfulness and mindfulness-based treatments can be traced to Kabat-Zinn's (1990) Mindfulness-Based Stress Reduction program. Mindfulness techniques have been incorporated into several treatments associated with improved outcomes (e.g., Grossman et al., 2004 and MAMIG, 2006). As mindfulness-based treatments have proliferated, researchers have attempted to operationally define mindfulness. Definitions tend to include an awareness component and attitudinal component (e.g., Bishop et al., 2004 and Kabat-Zinn, 1990). Most recently, Cardaciotto et al. (2008) have conceptualized mindfulness as a general tendency towards greater awareness of one's experiences, private and public, and bringing an attitude of acceptance and nonjudgment to these experiences. They suggest that awareness of experience and the attitude of acceptance with which one engages one's experience are orthogonal constructs. This makes the attitudinal component important in defining mindfulness, as awareness alone may be insufficient. Baer, Smith, and Allen (2004) found that in samples largely naïve to formal meditation practice, the tendency to be aware of one's experience was associated with greater judgment of that experience. Therefore, an attitude of openness and nonjudgment towards one's experiences may be a crucial mechanism of change in promoting the positive benefits associated with mindfulness (Shapiro, Carlson, Astin, & Freedman, 2006). This is consistent with an ACT definition of mindfulness, which includes contact with the present moment, acceptance of private experiences and willingness to remain in contact with them, and awareness of private experiences as content that are separate from the experience of one's self (Fletcher & Hayes, 2005). Within the ACT literature, acceptance of and willingness to embrace one's experience is reflective of a core ACT process that is considered the alternative to experiential avoidance ( Hayes et al., 1999). Consequently, awareness of experience without acceptance may not rule out experiential avoidance. Although individuals higher in mindfulness may experience negative thoughts, they appear to exhibit a greater ability to “let go” of negative thoughts and focus their attention on healthier ways of relating to their experiences (Frewen et al., 2008a). Greater mindfulness may enhance the ability of individuals to label negative affective stimuli, which may, in turn, allow them some degree of distance or detachment from these experiences (Creswell, Way, Eisenberger, & Lieberman, 2007). Consequently, cultivation of mindfulness can create a sea change in the way one approaches one's experience, allowing one to develop greater stability, meaning, flexibility, and less reactivity (Shapiro et al., 2006). The last ten years has seen an increase in the use of mindfulness-based treatments and techniques, in part to counter avoidance and help people engage their experiences more mindfully (see Baer, 2003). Although researchers have begun to explore the use of mindfulness in the treatment of trauma survivors (Batten et al., 2006 and Follette et al., 2004), there has been little research exploring the relationship between mindfulness and PTSD; thus, the relationship between mindfulness and PTSD symptoms remains unclear. 1.3. Mindfulness as a predictor of avoidance symptoms The main purpose of this study was to incorporate mindfulness into an experiential avoidance understanding of PTSD. Relationships between measures of mindfulness and experiential avoidance have been explored in previous research (Baer et al., 2004, Baer et al., 2006 and Hayes et al., 2004), but not within a trauma population. Understanding the relationship between mindfulness and PTSD could help researchers to tailor mindfulness and acceptance-based treatments for the treatment of trauma survivors. We were interested in exploring the relationship between experiential avoidance and PTSD avoidance symptoms, and whether mindfulness adds any additional predictive power. It was hypothesized that greater experiential avoidance would be predictive of greater PTSD avoidance symptoms severity, and that greater mindfulness would be predictive of lower PTSD avoidance symptom severity above and beyond measures of experiential avoidanc