استفاده از اندازه گیری انحراف شناختی معطوف به بررسی رابطه بین سرکوب افکار و ویژگی های شخصیت مرزی: مطالعه به چند روش

Previous research has demonstrated that thought suppression is an effortful emotion regulation strategy frequently used to avoid unwanted thoughts or emotions. This is a maladaptive strategy because it paradoxically increases the frequency of the unwanted thoughts or emotions. Although thought suppression has been linked to borderline personality disorder (BPD), most research has relied on self-report measures. This study employed a laboratory task (the Scrambled Sentences Test) assessing BPD-specific cognitive distortions to examine relationships between thought suppression and BPD features in a sample of undergraduate students (n = 181) including many with high levels of BPD features. Severity of BPD features was significantly correlated with the tendency to unscramble strings of words to create BPD-consistent sentences. This effect was more pronounced when the task was completed under a cognitive load (remembering a 6-digit number). Mediational models using bootstrapping suggested that this relationship may be explained by the tendency to engage in thought suppression. These results offer multi-method evidence for the proclivity to suppress unwanted and distorted cognitions in BPD.

Borderline personality disorder (BPD) is a serious and prevalent condition that includes unstable interpersonal relationships, severe externalizing and impulsive behavior, heightened emotional reactivity, intense negative affect, and identity disturbances (American Psychiatric Association, 2000). Maladaptive cognitive processes, including distorted beliefs and attempts to suppress unwanted thoughts, are strongly associated with the severity of BPD features (Baer, Peters, Eisenlohr-Moul, Geiger, & Sauer, 2012). Most previous research has relied on self-report measures to assess these variables. The present study used a cognitive processing task to examine relationships between BPD features, cognitive distortions, and thought suppression. 1.1. Cognitive distortions in BPD According to cognitive theorists, cognitive distortions are central to BPD, influencing how people with the disorder view themselves and the world and contributing to their intense negative emotions (Beck, Freeman, & Davis, 2004). Several models of distorted beliefs in BPD have been proposed. Beck and Freeman (1990) suggested that people with BPD are likely to endorse beliefs that they are bad, powerless, and vulnerable, and that the world is dangerous. Similarly, Pretzer (1990) proposed that three core beliefs underlie borderline pathology: the world and other people are dangerous and malevolent; the self is powerless and vulnerable; and the self is unacceptable and deserving of punishment. Empirical studies are generally consistent with these theoretical models. Although people with BPD endorse a wide range of negative beliefs, including those typical of many other disorders (Arntz, Dietzel, & Dreessen, 1999), particular beliefs have been shown to be especially common in BPD and to discriminate BPD from other personality disorders. These beliefs focus on distrust of others, rejection by others, dependency, helplessness, neediness, loneliness, unlovability, and the self as deserving of punishment (Arntz et al., 1999, Bhar et al., 2008 and Butler et al., 2002). 1.2. Thought suppression in BPD Thought suppression is the intentional attempt to push unpleasant or unwanted cognitions out of one’s consciousness. It is conceptualized as a maladaptive emotion regulation strategy because it paradoxically increases the frequency of the unwanted thoughts and associated negative affect (Wegner, 1992; see Abramowitz, Tolin, & Street, 2001, for a review). Studies have shown strong links between thought suppression and BPD symptoms, all utilizing self-report measures of thought suppression. Thought suppression was a stronger predictor of BPD features than automatic thoughts and dysfunctional attitudes (Geiger, Peters, Sauer-Zavala, & Baer, 2013). Thought suppression fully mediated the relationship between negative affect intensity/reactivity and BPD features and partially mediated the relationship between perceived parental criticism and BPD features (Cheavens et al., 2005), as well as fully mediated the relationship between an invalidating childhood environment and current symptoms of BPD (Sauer & Baer, 2009). These studies suggest that individuals who are more emotionally vulnerable and experienced invalidating parenting may be more prone to developing BPD features when thought suppression is used as an emotion regulation strategy. Thought suppression may persist because it relieves negative affect in the short term; however, over time, it likely leads to increased frequency and intensity of unwanted thoughts and emotions, subsequently requiring more extreme emotion regulation strategies such as parasuicidal behavior and drug use (Rosenthal, Cheavens, Lejuez, & Lynch, 2005; Chapman, Specht, & Cellucci, 2005). 1.3. Using a laboratory task to assess cognitive distortions and thought suppression Cognitive distortions and thought suppression are typically assessed using self-report methods, which may be susceptible to self-presentation strategies or demand characteristics. As an alternative, some authors have explored the use of the Scrambled Sentences Test (SST; Wenzlaff & Bates, 1998), a laboratory task in which participants are asked to rearrange six-word strings to create 5-word sentences (omitting one word). Depending on the omitted word, the unscrambled sentence can have either positive or negative valence. For example, “looks future my bright very dismal” can be “my future looks very bright” or “my future looks very dismal.” People with distorted thinking patterns are expected to produce more negative sentences. In some studies, participants are asked to unscramble the sentences while remembering a six-digit number (cognitive load). Because remembering the number is effortful, it reduces the cognitive resources available for distracting attention from unwanted thoughts. It has been hypothesized that people who are attempting to suppress negative thoughts will find it more difficult to do so in the cognitive load condition and will create more negative sentences under cognitive load than in the no-load condition (Wenzlaff & Bates, 1998). 1.4. Research using the Scrambled Sentences Test Several studies have shown that people with mood disorders create more negative sentences than healthy controls (Miklowitz et al., 2010 and Wenzlaff and Bates, 1998), and the proportion of negative sentences created is related to self-reported dysfunctional attitudes (Rude, Durham-Fowler, Baum, Rooney, & Maestas, 2010) and self-reported thought suppression (Miklowitz et al., 2010). In longitudinal studies, SST scores predict depressive symptoms at follow-up periods up to 30 months, and the load condition is a consistently stronger predictor of future depression than the no-load condition (Rude et al., 2003, Rude et al., 2002 and Rude et al., 2010). People with mood disorders currently in remission create significantly more negative sentences under the load than the no-load condition, suggesting that they may be attempting to suppress depressive thoughts and that the cognitive load disrupts these attempts (Wenzlaff & Bates, 1998). 1.5. Current study A recent review of experiential avoidance in BPD (Chapman, Dixon-Gordon, & Walters, 2011) noted that increased use of laboratory tasks would strengthen research on experiential avoidance processes such as thought suppression. Although substantial research links thought suppression and BPD, studies have relied heavily on self-report measures. Performance-based tasks that assess cognitive processing may provide more accurate information. Although previous studies have used the SST primarily in the context of depression, the SST may also be useful in the study of BPD. Thought suppression is associated with both disorders, and the cognitive distortions typical of depression, such as beliefs that one is weak, helpless, vulnerable, unlovable, and unworthy, are similar to those characteristic of BPD. The purpose of the current study was to extend previous findings on the SST to the study of BPD features. Using methods described later, we modified the SST to include BPD-specific content. Two hypotheses were tested to determine whether SST scores are related in expected ways to severity of BPD features: Hypothesis 1. The tendency to create negatively valenced sentences on the SST (with and without cognitive load) will be correlated with self-reports of the severity of BPD features, BPD-specific cognitive distortions, and the tendency to engage in thought suppression. Consistent with findings in depression, the cognitive load condition of the SST will be more strongly associated with these variables than will the no-load condition. Hypothesis 2. If the SST load score is a stronger predictor of BPD features than the no-load score, this will suggest that the cognitive load is important, presumably because it disrupts habitual attempts to suppress distorted thoughts typical of BPD. It was expected that the relationship between the SST load and BPD features will be statistically accounted for by self-reported thought suppression.

The data were screened for outliers (over five SDs above the mean) and missing data resulting in the exclusion of nine participants’ data. Participants also were excluded if they attempted fewer than 10 sentences in both blocks (1) or unscrambled less than 50% of the attempted sentences correctly (N = 2). These parameters ensure that participants understood the task and followed the directions. For all variables, skew and kurtosis values fell within normal limits ( Tabachnick & Fidell, 2000).