شمول‌ عاطفی: جدا کردن از روان رنجوری و از چهار عامل بزرگ؟

The goals of the current study were to use specific measures of affective lability and neuroticism to examine the nomological network surrounding both constructs and to test the degree to which a measure of general personality can account for variability in affective lability. Using a psychiatric outpatient sample (n = 48), we assessed personality disorder (PD) symptoms, personality, and level of functioning across a range of domains. Neuroticism and affective lability demonstrated a small but significant positive correlation and manifested a divergent pattern of correlations with PDs and measures of functioning. Specifically, neuroticism was correlated primarily with Borderline, Avoidant and Dependent PDs, whereas affective lability was primarily correlated with Cluster B PDs. In addition, neuroticism evinced significant correlations with a range of functional impairments, whereas affective lability was correlated only with self-harm. Regression analyses demonstrated that a substantial portion of the variance in affective lability scales can be explained by Five-Factor Model domains, particularly if the narrower facets are used. The current findings suggest that neuroticism and affective lability are related but in a complex manner that involves other basic personality domains in addition to neuroticism.

Neuroticism and affective lability are thought to be stable, trait-like dispositions associated with Axis I (Clark et al., 1994 and MacKinnon and Pies, 2006;) and Axis II (Sanislow et al., 2000 and Miller et al., 2004) disorders from the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV; American Psychological Association, 2000). While both constructs address facets of affectivity and emotional disturbance, they may be theoretically and descriptively separate ( Westen et al., 1997 and Miller and Pilkonis, 2006), and studies which conflate them may obscure their unique contributions to psychopathology and impairment. Neuroticism can be defined as the tendency to experience negative mood states, such as depression and anxiety and is sometimes referred to as one of the “Big Two” (along with Extraversion or Positive Emotionality) given its presence in most major models of personality. Neuroticism is temporally stable (e.g., Terracciano et al., 2006), has a substantial genetic component (Flint, 2004), and is closely related to disorders such as major depression and anxiety (e.g., Clark et al., 1994). Saulsman and Page (2004) found that, of the five major dimensions of personality included in the Five-Factor Model (FFM), neuroticism was among the most consistent correlates of the personality disorders (PDs). Neuroticism is also significantly related to suicidal ideation (Velting, 1999), self-harming behaviors (Williams and Hassanyeh, 1983), physical illness (Neeleman et al., 2002), and higher mortality rates (Shipley et al., 2007), as well as lower marital and sexual satisfaction (Fisher and McNulty, 2008). Affective lability, by contrast, is defined as the tendency to fluctuate between different mood states, including anger, depression, anxiety, and elation/hypomania (Harvey et al., 1989). Despite evidence that it is an important component of certain disorders such as borderline personality disorder (BPD; McGlashan et al., 2005) that are associated with significant impairment (Skodol et al., 2005), affective lability has received less attention as an independent construct. Evidence of this is highlighted by the limited assessment options for the construct. For example, as was the case in Miller and Pilkonis (2006), affective lability can be assessed through structured interview protocols for PDs; however, in this context affective lability is assessed only as part of the larger symptom checklist for BPD and other PDs (e.g., Histrionic Personality) and only through a limited number of questions. Alternatively, some self-report measures have been developed including the Affective Lability Scale (ALS; Harvey et al., 1989). Since PD interviews assess affective lability as a symptom embedded in a larger disorder, self-report measures like the ALS may allow for a more fine-grained and reliable assessment of fluctuation between specific types of mood states. Despite the importance of this construct and publication of this scale in 1989, research on the ALS has just begun in earnest, with a small body of research having been published since 2000. Since then, research has demonstrated that ALS scores are associated with BPD and bipolar II disorder (Henry et al., 2001), impaired decision-making (Jollant et al., 2007) and poorer distress-tolerance skills (Simons and Gaher, 2005). Some previous studies have examined neuroticism and affective lability as specific factors in psychiatric disorders. Most often, these studies have utilized samples of individuals diagnosed with BPD, as affective instability is viewed as a core feature of this disorder (Sanislow et al., 2000). However, in addition to difficulties regulating mood, vulnerability to negative mood states (i.e., neuroticism) is also characteristic of BPD (Westen et al., 2003 and Miller and Pilkonis, 2006), raising the question of the incremental validity of examining fluctuation in mood above and beyond impairment expected from chronic negative affect. Some studies have found that affective lability predicts poor functioning even after controlling for neuroticism (Bagge et al., 2004). Alternatively, other data suggest that neuroticism is a stronger unique predictor of most forms of functioning (Miller and Pilkonis, 2006). While initial data suggest that neuroticism and affective instability are separable but related constructs, the extent to which affective instability can be understood and assessed using general models of personality is unresolved. It is unclear whether constructs like affective lability are entirely separate from emotional difficulties captured by comprehensive models of personality such as the FFM (i.e., Berenbaum et al., 2003) or whether affective lability simply reflects a combination of traits such as high neuroticism and low extraversion/positive emotion (Watson, 2003). This is important as it has been argued that PDs might be more parsimoniously characterized using a general model of personality (e.g., Widiger and Trull, 2007). Given the importance of affective instability to disorders like BPD, this question is of particular relevance. The goal of the current study is to examine the nomological network surrounding both neuroticism and affective lability in a clinical sample. As noted earlier, Miller and Pilkonis (2006) suggested that neuroticism and affective lability appear to be similar but distinct constructs that manifest only partially overlapping relations with personality traits and disorders, and various aspects of functioning. The measure of affective instability in that study, however, was created by summing scores on four PD symptoms taken from three different PDs. In the current sample, we attempt to replicate many of these findings while using a prominent self-report measure of affective instability, the ALS. In addition, we extend this previous work by using validated self-report measures of dyadic functioning and quality of life rather than using more global, expert ratings of impairment. The use of self-report ratings for both affective lability and neuroticism is a strength here, as it reduces concerns that method variance is differentially influencing the size or nature of the relations between these constructs and the remaining criteria. We also extend the previous work in an important way by examining how much of the variance in the ALS can be accounted for by a measure of the FFM (i.e., the Revised NEO Personality Inventory [NEO PI-R]; Costa and McCrae, 1992) and whether the ALS manifests unique relations with relevant criteria such as PDs, psychological distress, and functioning, once controlling for the variance explained by the NEO PI-R. Based on previous research (Simons and Gaher, 2005; Miller and Pilkonis, 2006 and McCloskey et al., 2008), we hypothesize that neuroticism and affective lability will demonstrate a small to moderate positive correlation and that neuroticism will be significantly negatively related to agreeableness and conscientiousness and negatively or non-significantly related to extraversion. We also test whether neuroticism interacts with other NEO PI-R dimensions to predict the ALS scores. That is, the relation between neuroticism and affective lability may be contingent upon high or low levels of other basic personality traits. Building on the results of Miller and Pilkonis with regard to affective lability and the NEO PI-R, besides the correlation with neuroticism, we expect ALS scores to be significantly negatively related to agreeableness. With regard to the PDs, we expect neuroticism to be related to Borderline, Avoidant and Dependent PDs, whereas we expect affective instability to be correlated primarily with the Cluster B PDs and Dependent PD. With regard to impairment, we expect that neuroticism will be the stronger, more consistent correlate of psychological distress and quality of life, whereas both neuroticism and affective lability will be correlated with poorer romantic functioning. We expect significant relations for both neuroticism and affective lability with self-reports of intimate partner violence and self-harm (Williams and Hassanyeh, 1983 and Miller and Pilkonis, 2006).