افکار سرکوب واسطه ارتباط بین احساس منفی و علائم اختلال شخصیت مرزی

The purpose of this study was to examine the relationships among negative affect, childhood sexual abuse (CSA), thought suppression, and diagnostic symptoms of borderline personality disorder (BPD) in a community sample (n=127n=127). Findings suggest that the temperamental variable negative affect intensity/reactivity was a stronger predictor of BPD symptoms than CSA. In addition, results indicated that higher thought suppression mediated the relationship between negative affective intensity/reactivity and BPD symptoms, after controlling for a history of CSA. Overall, findings suggest that (a) negative affectivity may be a better predictor of BPD symptoms than CSA, and (b) chronic efforts to suppress unpleasant thoughts may be a regulation strategy underlying the relationship between intense negative emotions and BPD symptoms.

Borderline personality disorder (BPD) is a serious mental health problem as evidenced by high rates of inpatient psychiatric service utilization (Swigar, Astrachan, Levine, Mayfield, & Radovich, 1991), risk for suicide (Linehan, Rizvi, Shaw-Welch, & Page, 2000), and rates of psychiatric co-morbidity (Skodol et al., 2002a). Findings from recent studies suggest that three core features largely characterize BPD: disturbed interpersonal relatedness, behavioral dyscontrol, and affective dysregulation (Skodol et al. (2002a) and Skodol et al. (2002b); Siever et al., 2002). However, despite growing consensus regarding these core features of BPD, there remains uncertainty as to whether distal environmental factors (e.g., childhood trauma) or temperamental factors (e.g., affect intensity) are more useful predictors of the disorder. In addition, although recent studies have provided preliminary evidence for the role of emotion regulation in the presentation of BPD features (Cheavens et al., in press; Yen, Zlotnick, & Costello, 2002), the extent to which maladaptive efforts to regulate emotions have a central role in BPD is unknown. The purpose of this study is to begin addressing both issues by examining the relationships among negative affectivity, childhood sexual abuse, thought suppression, and diagnostic symptoms of BPD. Temperamental factors: Individuals with BPD exhibit significant problems associated with affective instability ( Skodol et al., 2002a; Linehan, 1993), and some argue that it is the core feature of BPD ( Linehan, 1993). Furthermore, individuals with BPD have been hypothesized to have a biological predisposition to exhibit heightened affective intensity and reactivity ( Linehan, 1993). Empirical investigations have provided some preliminary support for these contentions. For example, compared with controls, individuals with BPD report greater intensity of negative affect and greater number of changes in negative affect over time ( Levine, Marziali, & Hood, 1997; Stein, 1996). Similarly, BPD is associated with higher levels of dysphoric affect compared with other personality disorders ( Zanarini et al., 1998). Evidence also suggests that higher affect intensity predicts a greater number of BPD diagnostic symptoms, even after controlling for level of depressive symptoms ( Yen et al., 2002a). Recently, Cheavens et al. (in press) found that negative affect intensity and reactivity were associated with higher levels of BPD features, including impulsivity, aggression, and interpersonal sensitivity. In sum, results from studies examining negative affectivity and BPD are consistent with the notion that BPD is characterized by heightened affective instability. Distal environmental factors: In addition to temperamental factors such as negative affectivity, distal environmental factors also are associated with greater BPD symptoms, and early environmental affiliative and/or childhood trauma related problems are widely considered as important in the development of BPD (e.g., Graybar & Boutilier, 2002). One early environmental factor associated with BPD is childhood sexual abuse (CSA). Individuals with BPD commonly report a history of CSA (e.g., Herman, Perry, & van der Kolk, 1989; Paris, Zweig, & Guzder (1994a) and Paris, Zweig, & Guzder (1994b); Zanarini et al., 1997). Greater severity of CSA (e.g., higher frequency of abuse, the use of force, molestation by a family member, etc.) has been found to be associated with a greater number of BPD symptoms among inpatients with BPD ( Zanarini et al., 2002). In addition, Yen et al. (2002b) found that a history of CSA was associated specifically with BPD compared with other personality disorders. Although CSA is associated with BPD, a history of sexual abuse in childhood is unlikely to be the sole or primary causal variable in the development of BPD ( Goodman & Yehuda, 2002; Graybar & Boutilier, 2002). A recent meta-analysis found a moderate effect size (r=.28r=.28) associated with the relationship between CSA and BPD ( Fossati, Madeddu, & Maffei, 1999), suggesting a positive relationship between these variables. Thus, although CSA is likely not pathognomic of BPD symptoms, it is appropriate to include this variable in studies investigating processes underlying the disorder. In addition, doing so could provide further insight into the relative contributions of temperamental and distal environmental factors in the development of BPD. Emotion regulation and BPD: Temperament personality theorists have defined reactivity as “the excitability, responsivity, or arousability of the behavioral and physiological systems, whereas self-regulation refers to the neural and behavioral processes functioning to modulate this underlying reactivity” ( Rothbart & Derryberry, 1981, p. 40; Rothbart, Ahadi, & Evans, 2000). Although emotion regulation is a complex construct ( Gross, 1998), difficulties regulating or modulating emotional reactivity are considered central to BPD (e.g., Linehan, 1993; Pukrop, 2002). Yen et al. (2002a) reported that problems with emotion regulation predicted a greater number of BPD diagnostic symptoms after controlling for depressive symptoms and temperamental affect intensity. However, there are few studies examining specific emotion regulation processes in BPD. One regulation strategy that may be problematic in BPD is the tendency to respond to negative affect with attempts to avoid or escape aversive emotion and cognition. For example, higher levels of BPD symptoms are associated with more avoidance/escape in response to a recent stressor (Bijttebier & Vertommen, 1999). In addition, substance abusers with BPD use more avoidance/escape strategies when compared to substance abusers without BPD (Kruedelbach, McCormick, Schulz, & Grueneich, 1993). More generally, the tendency to chronically and deliberately attempt to reduce the frequency or intensity of unpleasant cognitions is associated with increased psychopathology (e.g., Purdon, 1999). Of particular relevance to the current study, Lynch and colleagues have examined thought suppression as a component of emotional inhibition in a series of studies. Findings from these studies suggest that greater inhibition of emotional experience via thought suppression mediates the relationship between (a) negative affect and psychological distress in both undergraduate and clinical samples (Lynch, Robins, Mendelson, & Krause, 2001), (b) childhood maltreatment and adult psychological distress in a non-clinical sample (Krause, Mendelson, & Lynch, 2003), (c) negative affectivity/reactivity and features of BPD in an undergraduate sample (Cheavens et al., in press), and (d) negative affect intensity/reactivity and higher levels of suicidal ideation and hopelessness in a sample of depressed older adults (Lynch, Cheavens, Morse, & Rosenthal, in press). In addition, thought suppression has been examined in a sample of treatment-seeking depressed older adults (Rosenthal et al., in press). Findings suggested that, compared to those with the lowest levels of thought suppression at pre-treatment, patients with the highest levels of thought suppression at pre-treatment had more depressive symptoms at a six month follow-up assessment, over and above pre-treatment depressive symptoms. Taken together, recent studies appear to suggest that thought suppression may play an important role in psychopathology. However, to date, no studies have specifically examined whether thought suppression mediates the relationship between temperamental or distal environmental variables and BPD diagnostic symptoms. Current study : The current study utilized a community sample (n=127n=127) in order to examine two questions. First, we investigated the extent to which a distal environmental factor (i.e., CSA) and a temperamental factor (i.e., negative affect intensity/reactivity) were associated with current BPD symptoms. Second, in order to replicate and extend the findings of Cheavens et al. (in press), we examined a mediational model whereby a maladaptive emotion regulation strategy (i.e., thought suppression) was hypothesized to mediate the relationship between negative affect intensity/reactivity and BPD symptoms, after controlling for the effects of CSA.

The first step in the data analytic plan was to examine the distribution of the data to evaluate the influence of potential outliers, skewness, and kurtosis. Because CSA scores were positively skewed, these scores were square root transformed, and the transformed scores were used in subsequent analyses. The means and standard deviations for this variable, however, are presented without transformation to facilitate interpretation. To correct for family wise error rates, a Bonferroni correction procedure was used to determine significance in the correlation and regression analyses. Consequently, the alpha necessary to reach statistical significance was .003. The correlations among the variables are presented in Table 2. Of the 15 correlations, all were significant at the p<.003p<.003 level. Due to the theoretical link and high correlation between AIM-NI and AIM-NR (r=.63r=.63), these variables were combined, and the variable Negative AIM (AIM-N) was used as a measure of negative affectivity for all subsequent analyses. Table 1 summarizes the mean scores, standard deviations, and Cronbach alpha estimates for the measures (AIM-NI, AIM-NR, AIM-N, CSA, WBSI, and BPD symptoms) (Table 1 and Table 2).