Although, on an accumulated level, survivors of interpersonal trauma tend to have more problems with psychological functioning compared to their non-abused peers, not every abused individual develops posttraumatic symptoms as a response to the violence they have experienced (Briere & Elliott, 1994; Collishaw et al., 2007, Lynskey & Fergusson, 1997). This has led researchers to the assumption that there may be additional factors involved that influence the relationship between interpersonal trauma and later psychological functioning (e.g. Ozer et al., 2003; Shapiro & Levendosky, 1999).Research on this subject has yielded both internal and external variables that were thought to constitute such factors (e.g.; Aspelmeier, Elliott, & Smith, 2007; Browne & Winkelman, 2007; Collishaw et al., 2007; Elwood & Williams, 2007; Muller, Sicoli, & Lemieux, 2000; Roche et al., 1999; Shapiro & Levendosky, 1999). In the following sections, attachment security will be discussed as one of these intervening variables. Theoretical grounds as well as empirical evidence regarding its influence on PTSD following interpersonal trauma will be reviewed.
Moderational versus mediational models. In the empirical literature, different approaches have been used to investigate the potential influence of third variables. While many studies employed mediational models, some tested moderational effects. According to Baron and Kenny (1986), a mediating variable accounts for the relationship between a predictor and an outcome variable. If, for example, attachment insecurity mediates the relationship between a traumatic life event and posttraumatic stress symptoms, this means that the trauma causes changes in attachment which in turn lead to the posttraumatic stress symptoms. A moderating variable, on the other hand, influences the strength and/or direction of an already existing association between a predictor and an outcome. The choice which model to test depends on prior theoretical assumptions regarding the nature of the presumed influence of the third variable as well as observed associations between the respective variables. Baron and Kenny (1986) suggest testing a mediational model if there is a strong association between the
predictor and the outcome variable. A moderational model, on the other hand, should be tested if this association is weak or inconsistent.
Theoretical grounds. As interpersonal trauma, most notably physical and sexual abuse, is embedded in an interpersonal context, the quality of social relationships was deemed a possible mediator between this type of trauma and its impact on the survivor’s mental health (Alexander, 1992; Collishaw et al., 2007). Studies investigating the mediating effect of a person’s experiences in social relationships frequently applied attachment theory as a conceptual framework because it is interpersonal relationships in which attachment patterns are assumed to be primarily established and maintained (Sandberg et al., 2010). The
attachment-related working models of the self (dependence/anxiety) and of the other (avoidance) are developed early in life through the child’s relationship with his or her primary caregiver (Bowlby, 1973; see section 1.5.2). Therefore, these internal working models are likely to be particularly affected by adverse interpersonal events in childhood. In turn, attachment patterns are expected to either bring forward or prevent trauma-related psychosocial problems, depending on whether they are classified as secure or insecure. (Roche et al., 1999) Riggs et al. (2007) reported a significant association between the attachment dimensions avoidance and anxiety on the one hand and PTSD on the other hand. A significant association between attachment anxiety and PTSD was also reported by Muller et al. (2000), but in this study attachment avoidance and PTSD were unrelated. As for the mechanisms underlying this relationship, Cloitre et al. (2008) found empirical support for an effect of attachment insecurity on functional impairment, following childhood abuse, through emotion regulation on the one hand and expectations of social support on the other hand. Similarly, Benoit, Bouthillier, Moss, Rousseau, and Brunet (2010) found that the association between attachment security and PTSD, following trauma in adulthood, is established through the mediating effect of emotion-focused coping strategies.
Although a link between attachment security and PTSD has been established, the
mechanisms underlying this association have not yet been clearly identified (Benoit et al., 2010). Cloitre et al. (2008) suggested that attachment insecurity may affect emotion regulation which, in turn, could increase the chances of developing PTSD. Muller et al. (2000) follow the same approach by postulating that both insecure attachment and PTSD are related to problems of affect regulation. Children are assumed to learn to regulate their
affective states in interactions with their primary caregivers (Alexander, 1992). However, certain attachment styles may not permit the acquisition of adequate emotion regulation strategies and may thereby increase an individual’s vulnerability for developing PTSD (Muller et al., 2000). Sandberg et al. (2010) suggested three pathways through which disrupted attachment patterns may contribute to posttraumatic stress. First, others may
become internally represented as malevolent or dangerous while the self may be perceived as helpless and vulnerable. This, in turn, may undermine a person’s sense of safety and security. Second, guilt, shame, and other negative feelings that are related to insecure attachment may impair a person’s strategies for effective emotion regulation and thereby increase the risk for posttraumatic stress. Third, due to the perception of others as rejecting, inconsistent, or non- trustworthy, the affected individual’s perception or use of social support may be affected. The following sections of this chapter will present empirical evidence regarding the mediating effect of attachment insecurity on PTSD and other indicators of psychological functioning. Besides, two studies will be reviewed that tested a moderational model. Evidence regarding a mediating effect of attachment. Roche et al. (1999) applied
Bartholomew’s (1990) four-category model of attachment in adulthood in order to examine the role of attachment in the context of childhood sexual abuse. Using the Relationship Questionnaire (RQ, Bartholomew & Horowitz, 1991), Roche et al. found that the relationship between childhood sexual abuse and trauma-related symptoms later in life is mediated by the individual’s attachment style. When attachment type was taken into account, childhood sexual abuse did not predict the degree of trauma-related symptoms, assessed with the Trauma Symptom Inventory (TSI; Briere, 1995). At the same time, the association between attachment and trauma-related symptom levels remained constant when childhood sexual abuse was controlled for. Shapiro and Levendosky’s (1999) findings suggest that high attachment security is significantly associated with low psychological distress among adolescents (operationalized by measures of depression and trauma-related symptoms) who were exposed to sexual abuse as children. A path analysis supported the assumption that attachment security mediates the relationship between childhood sexual abuse and psychological distress. Similarly, Dimitrova et al. (2010) found that the extent to which a person feels comfortable with closeness and intimacy in relationships mediates the effect of childhood sexual abuse on psychological functioning (assessed by the DSM-IV Global
Assessment of Functioning). Both Shapiro and Levendosky (1999) and Dimitrova et al. (2010) applied the Adult Attachment Scale (AAS; Collins & Read, 1990) for the assessment of attachment styles. Cloitre, Stovall-McClough, Zorbas, and Charuvastra (2008) studied a sample of individuals with a history of childhood sexual abuse and found that participants with insecure attachment had greater functional impairment than those reporting secure attachment. Results of a path analysis suggested that insecure attachment has an indirect effect on a person’s functional status through two intervening variables: reduced expectations of social support on the one hand and inadequate regulation of negative emotions on the other hand.
Several studies that applied the two-dimensional model of adult attachment reported only partial support for a mediating effect of attachment. Sandberg et al. (2010) and Limke et al. (2010) found attachment-related anxiety to mediate the relationship between sexual
maltreatment and psychological adjustment, but did not obtain the same result for the avoidance dimension.
Evidence regarding a moderating effect of attachment. Investigations that tested a moderating effect of attachment insecurity obtained heterogeneous results. In a study involving a female student sample, Aspelmeier et al. (2007) did not find that attachment security in close-adult relationships, assessed categorically, moderates the effect of childhood sexual abuse on trauma-related symptoms.
Moderational effects of attachment were also tested with individuals abused in adulthood. Scott and Babcock (2010) obtained empirical support for a moderating effect of both attachment avoidance and dependence4 on PTSD. Contrary to this finding, Elwood and Williams (2007) did not find that attachment-related avoidance and anxiety moderate the association between adult interpersonal trauma and psychological functioning. A possible explanation for this discrepancy in results could be that the participants in Elwood and Williams’ (2007) study were college students who were not necessarily involved in romantic relationships (Scott & Babcock, 2010), while Scott and Babckock (2010) recruited a
community sample of individuals that were all living in a relationship. Furthermore, these
two studies used different measures of attachment and trauma-related symptoms and Scott and Babcock (2010) focused on physical abuse while Elwood and Williams included individuals who had experienced either physical or sexual abuse.