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Suicide and Life-Threatening Behavior 44 (6) December 2014 © 2014 The American Association of Suicidology DOI: 10.1111/sltb.12098
PTSD Symptom Clusters Are Differentially Associated with Components of the Acquired Capability for Suicide KELLY L. ZUROMSKI, BS, MARGARET T. DAVIS, MS, TRACY K. WITTE, PHD, FRANK WEATHERS, PHD, AND CHRISTY BLEVINS, MS
Previous research has established the link between posttraumatic stress disorder (PTSD) and suicidal behavior. In the current study, constructs proposed to explain this relationship were examined, applying the framework of the interpersonal-psychological theory of suicide (IPTS). Relationships between acquired capability for suicide (ACS; i.e., fearlessness about death [FAD] and pain tolerance) and specific PTSD symptom clusters were explored. In a sample of 334 trauma-exposed undergraduates, anxious arousal and FAD were negatively associated, and numbing and pain tolerance were positively associated. Results establish a foundation for investigating the role of ACS in understanding observed relationships between suicidal behavior and PTSD symptoms. The relationship between posttraumatic stress disorder (PTSD) and suicidal behavior is well established (Nock et al., 2009; Panagioti, Gooding, & Tarrier, 2009, 2012). Specifically, studies comparing individuals with PTSD to trauma-exposed but healthy controls have reported higher risk of suicide ideation (Krysinska & Lester, 2010; Panagioti et al., 2012), sucide attempts (Davidson, Hughes, Blazer, & George, 1991; Kessler, Borges, & Walters, 1999), and death by suicide (Gradus et al., 2010). These findings suggest that something about PTSD, either at the syndrome or symptom cluster level, confers risk of suicidal behavior. However, understanding of this increased risk is limited by (1) the predominantly atheoretical nature of prior KELLY L. ZUROMSKI, MARGARET T. DAVIS, TRACY K. WITTE, FRANK WEATHERS and CHRISTY BLEVINS, Department of Psychology, Auburn University, Auburn, AL, USA. Address correspondence to Tracy K. Witte, Department of Psychology, Auburn University, 226 Thach Hall, Auburn, AL 36849-5214; E-mail: [email protected]
research (Panagioti et al., 2009), and (2) a focus on PTSD diagnostic status or overall symptom severity rather than on specific PTSD symptom clusters or other potentially relevant trauma-related factors (e.g., trauma type or level of exposure). In the current study, we used the interpersonalpsychological theory of suicide (IPTS; Joiner, 2005; Van Orden et al., 2010) as a framework to address these limitations and investigate potential mechanisms underlying the relationship between PTSD, or trauma exposure more broadly, and suicide attempts. The IPTS identifies two constructs as proximal causes of suicidal desire: thwarted belongingness (i.e., social isolation) and perceived burdensomeness (i.e., feeling that one is a liability to others). However, the IPTS specifies that an individual must possess not only suicidal desire, but also a lowered fear of death and elevated physical pain tolerance, to engage in the fearsome and painful act of lethal self-injury. These two components constitute the acquired capability for suicide (ACS; Van Orden
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et al., 2010). Specifically, the IPTS proposes that suicidal desire develops into suicidal intent only in the presence of fearlessness about death (FAD) and that suicidal intent develops into a lethal suicide attempt only in the presence of pain tolerance (i.e., individuals with higher pain tolerance will be able to make more lethal attempts). Without FAD and pain tolerance, the IPTS proposes that an individual will not be capable of enacting self-harm even if he or she has a strong desire for suicide (Joiner, 2005; Van Orden et al., 2010). This capability is posited to develop and occur independently of one’s desire for suicide; thus, an individual could have an elevated ACS even if he or she does not endorse suicidal ideation (Joiner, 2005; Smith & Cukrowicz, 2010; Van Orden et al., 2010). Past research on ACS has demonstrated that FAD is associated with suicidal intent among suicide attempters (Ribeiro et al., 2014). Further, both FAD and pain tolerance can differentiate suicide attempters from ideators (Smith, Cukrowicz, Poindexter, Hobson, & Cohen, 2010). ACS may be especially relevant in explaining the link between trauma exposure and suicide attempts. Specifically, the capability for suicide is proposed to develop through repeated exposure to various life events or experiences that are painful and/ or fear-inducing. Joiner (2005) and Van Orden et al. (2010) suggested that repeated exposure to painful and/or fear-inducing stimuli (e.g., trauma exposure) results in habituation to fear of death and/or physical pain, which makes an individual more capable of suicidal behavior. In fact, a growing literature suggests that traumatic experiences including combat exposure (Kang & Bullman, 2008), childhood maltreatment (Beautrais, 2001), and exposure to suicidality in others (Insel & Gould, 2008) are all linked to suicidal behavior, and Van Orden et al. (2010) suggested that these experiences function as painful and/or fear-inducing events that can contribute to ACS. As such, the main focus of our study was to use the IPTS as a theoretical framework to
683 examine the relationship between trauma exposure and both facets of ACS. Two qualitative studies have suggested that the IPTS provides a useful framework for examining suicidal behavior among trauma-exposed military samples (Anestis, Bryan, Cornette, & Joiner, 2009; Brenner et al., 2008). In addition, regarding ACS specifically, research has demonstrated an association between ACS and trauma exposure as well as severity of PTSD symptoms (Bryan, Cukrowicz, West, & Morrow, 2010; Bryan, Hernandez, Allison, & Clemans, 2012). Nevertheless, these studies are limited in that they only considered overall PTSD symptom severity and did not evaluate specific PTSD symptom clusters. This approach is problematic given the considerable evidence that PTSD is a multifaceted construct comprising as many as five distinct, yet related, symptom clusters (Elhai et al., 2011). In light of the multifaceted nature of PTSD, some researchers have explored the relationships between symptom clusters and ACS. Within the framework of the IPTS, Selby et al. (2010) emphasized the centrality of reexperiencing symptoms, arguing that individuals endorsing these symptoms are mentally rehearsing past exposure to past painful and/or fear-inducing traumatic stimuli, which could contribute to both facets of ACS. In support of this argument, Bryan and Anestis (2011) found a significant relationship between ACS and the reexperiencing symptom cluster in a sample of deployed military personnel. However, this study did not investigate other symptom clusters besides reexperiencing. Further, the two facets of ACS were combined for analyses, making it impossible to explore discriminant relations between reexperiencing and FAD and pain tolerance. Moreover, no studies have employed the use of the fivefactor dysphoric arousal model of PTSD (Elhai et al., 2011) in investigating the relationship between PTSD symptoms and ACS. This model separates hyperarousal into dysphoric and anxious arousal clusters, and it is quite possible that differential
684 relationships may exist between the separate arousal categories and ACS. Outside the framework of the IPTS, research examining the relationship between trauma exposure and suicidal behavior offers evidence of potential relationships between PTSD symptom clusters and ACS. This body of research is limited, however, in that the existing studies (e.g., Ben-Ya’acov & Amir, 2004; Tarrier & Gregg, 2004) use the Diagnostic and Statistical Manual (DSM-IV; American Psychiatric Association [APA], 1994) model of PTSD symptom structure. The most problematic aspect of the DSM-IV model is that it combines avoidance and numbing symptoms into one cluster, despite factor analytic research indicating that avoidance and numbing symptoms represent distinct clusters (see Asmundson, Stapleton, & Taylor, 2004, for a review). Previous research suggests that the separation of avoidance and numbing symptoms is important due to their etiological differences. For instance, Litz (1992) argued that numbing symptoms arise as a result of habituation to chronic emotional arousal experience after repeated exposure to trauma cues, whereas avoidance symptoms are the result of conscious coping processes (Foa, Zinbarg, & Rothbaum, 1992). Although some numbing symptoms likely reflect interpersonal disruption, and thus may relate more directly to suicidal ideation (e.g., Davis, Witte, Weathers, & Blevins, in press), it seems that other numbing symptoms may be relevant to ACS. For instance, previous pain research has demonstrated decreased pain sensitivity following repeated painful stimulation (i.e., stress-induced analgesia) in individuals with PTSD compared with controls (e.g., Strigo et al., 2010; Van de Kolk, Pitman, & Orr, 1989), and this stress-induced analgesia is thought to be one manifestation of numbing symptoms (Foa et al., 1992). Considered within the framework of the IPTS, both components of ACS (i.e., FAD and heightened pain tolerance) are proposed to develop through the same process of habituation following
PTSD SYMPTOMS
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repeated exposure to painful and/or fearinducing stimuli (Van Orden et al., 2010). Because of the similar etiology of numbing symptoms and ACS, numbing symptoms may be more strongly related to facets of ACS than avoidance symptoms. On the contrary, presence of avoidance symptoms may be more reflective of lower levels of ACS, if individuals are likely to avoid trauma-related stimuli (e.g., Foa et al., 1992) that would otherwise result in habituation to fear of death and pain (Litz, 1992). Whereas numbing symptoms are conceptualized as developing in response to chronic hyperarousal (Litz, 1992) and seem consistent with increased ACS, experience of hyperarousal symptoms (e.g., hypervigilance, exaggerated startle response) may function similarly to avoidance symptoms and also be negatively associated with ACS. Hyperarousal symptoms reflect impaired fear inhibition (Jovanovic et al., 2010), which seems to align theoretically with the FAD facet. Specifically, individuals who experience hyperarousal symptoms have not habituated to exposure to trauma-related stimuli and thus have lower levels of fearlessness, which may also relate to fear of death-related stimuli (i.e., lower FAD). However, existing research examining the relationship between hyperarousal symptoms and suicide attempts (e.g., Ben-Ya’acov & Amir, 2004; Tarrier & Gregg, 2004) is methodologically limited (e.g., combining PTSD symptoms in analyses; small sample sizes), and thus, it is difficult to evaluate these findings within the framework of the IPTS. While some research within the IPTS field has attempted to clarify the relationship between PTSD symptom clusters (i.e., reexperiencing) and ACS, other variables related to trauma exposure, such as trauma type and level of exposure, remain understudied. Past research within the trauma field has demonstrated that history of suicide attempts is more strongly associated with trauma exposure involving rape or being threatened with a weapon compared with other types of traumatic events (Floen
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& Elklit, 2007). This research suggests that interpersonal trauma (i.e., traumas perpetrated by another person, such as physical/ sexual assault) is more associated with suicide attempt and thus may be more strongly associated with ACS than noninterpersonal trauma (i.e., traumas not perpetrated by another person, such as motor vehicle accidents or natural disasters). Although no studies have directly compared trauma types in the context of ACS, research by Fillingim and Edwards (2005) demonstrated that history of childhood abuse is associated with decreased sensitivity to experimentally induced pain compared with healthy controls, which seems consistent with the heightened physical pain tolerance facet of ACS, and may provide indirect evidence of increased ACS among individuals exposed to interpersonal trauma. Furthermore, level of exposure to trauma (i.e., directly experiencing a traumatic event versus witnessing it or learning that it happened to a loved one) and suicidal behavior has not been addressed in past literature, although this distinction is an important aspect of Criterion A (stressor criterion) for PTSD (APA, 1994). Because the IPTS suggests that firsthand exposure to painful and/or fear-inducing events contributes to ACS (Joiner, 2005), direct experience of trauma may contribute more to ACS, and subsequently, to one’s risk of suicidal behavior. Thus, this component of traumatic experience was also explored in the current study. The current study had two main aims. The primary aim was to evaluate theory-driven hypotheses related to the relationships between PTSD symptom clusters and components of ACS. First, we hypothesized that both ACS facets (i.e., FAD and pain tolerance) would be positively associated with the reexperiencing symptom cluster, consistent with past research. Second, we predicted that the numbing symptom cluster would be positively related to both ACS facets, consistent with trauma literature on habituation to trauma-related cues resulting in blunted
685 responses. Third, we hypothesized that the avoidance symptom cluster would be negatively related to both ACS facets. Fourth, we predicted that both dysphoric and anxious arousal symptom clusters would be negatively associated with both ACS facets, considering the fear-based etiology of hyperarousal symptoms. Our secondary aim was to investigate the relationship between other features of trauma exposure and ACS. Related to trauma type, we predicted that experience of interpersonal trauma, compared with noninterpersonal trauma, would be positively associated with both ACS facets, consistent with past research on interpersonal trauma and risk of suicide attempts. Lastly, consistent with the emphasis the IPTS places on firsthand experience of painful and/or fear-inducing events and ACS, we hypothesized that direct experience of trauma (as opposed to witnessing or hearing about a traumatic event) would be positively associated with both ACS facets.
METHOD
Participants and Procedure Participants were undergraduate students enrolled in psychology courses at a large public university in the southeastern United States. After approval from the university’s institutional review board, individuals who self-identified as having experienced a very stressful life event (N = 512) were recruited using an online pool of undergraduate psychology students. This data set was also utilized in another recent study on traumatic life events (i.e., Davis et al., in press); however, although there is some overlap in the measures used in the current study and Davis et al., the study aims and primary analyses are unique. Participants completed a battery of computerized self-report questionnaires during proctored data collection sessions. Only participants whose designated worst event met DSM-IV Criterion A1 were included in
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analyses. The final sample included 334 individuals (72.2% female), whose mean age was 19.65 (SD = 3.30; range from 17 to 54). Most participants were non-Latino White/European origin (79.3%); 12.6% were Black; 3.6% were Latino/Hispanic; 3% were Asian American/Pacific Islander; 1.5% identified as multiracial or other. Measures Fearlessness About Death. The Acquired Capability for Suicide Scale (ACSS; Van Orden, Witte, Gordon, Bender, & Joiner, 2008) was originally developed as a 20-item self-report measure to assess both FAD and pain insensitivity. However, a recent psychometric investigation of the ACSS supports the use of a 7-item subscale of the ACSS to assess FAD (ACSS-FAD; Ribeiro et al., 2014). Several other investigations have found discriminant relations between various constructs and the ACSSFAD and pain tolerance (Witte, Correia, & Angarano, 2013; Witte, Gordon, Smith, & Van Orden, 2012). In the current study, although we administered the full ACSS, the ACSS-FAD subscale was utilized as a measure of FAD. Items including I am not at all afraid to die and The fact that I am going to die does not affect me were rated on a 5-point scale, with higher scores indicating greater FAD. Internal consistency for the 7-item ACSS in the current sample was adequate (a = .83). Pain Tolerance. Pain tolerance was assessed using one item from the 20-item version of the Acquired Capability for Suicide Scale (i.e., I can tolerate a lot more pain than most people; ACSS; Van Orden et al., 2008) and one from the Discomfort Intolerance Scale (i.e., I can tolerate a great deal of physical discomfort; DIS; Schmidt, Richey, & Fitzpatrick, 2006). Similar items have been shown to load strongly onto a pain tolerance factor in undergraduate and clinical samples (Schmidt et al., 2006). Both items were rated on 5-point scales and coded such that higher scores reflected higher pain tolerance. Internal consistency
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ACQUIRED CAPABILITY
for this measure of pain tolerance was adequate (a = .85). Combined Measure of Acquired Capability. In an attempt to replicate previous findings, we also derived a total score for the 5-item subset of the ACSS administered by Bryan and Anestis (2011), which conflates FAD and pain tolerance and includes some items that do not clearly indicate either of these constructs. This measure contained the following items: (1) The sight of a dead body is horrifying to me; (2) I like watching aggressive contact in sports games; (3) I can tolerate a lot more pain than most people; (4) I am not at all afraid to die; and (5) Things that scare most people do not scare me. Of these five items, only one (i.e., item (4)) is included in the Ribeiro et al. (2014) FAD subscale. These items were rated on a 5point scale, with higher scores indicating higher levels of ACS. Internal consistency for this measure in the current sample was .60, which is consistent with previous reports using this scale (Bryan & Anestis, 2011) and reflects the diverse content of the five items. Trauma Type and Exposure Level. We assessed trauma event type and exposure level with the Life Events Checklist (LEC), the self-report trauma section of the Clinician-Administered PTSD Scale (CAPS; Blake et al., 1995; Weathers, Keane, & Davidson, 2001). The LEC assesses exposure to 17 types of traumatic events (e.g., physical assault, transportation accident) and has demonstrated sound psychometric properties (Gray, Litz, Hsu, & Lombardo, 2004). As described by Davis et al. (in press), following completion of the LEC, participants indicated their worst traumatic event, wrote a brief narrative description of it, and used it as the basis for reporting PTSD symptoms. A team of graduate students supervised by the fourth author (FW) coded these narrative descriptions to determine whether the index event met DSM-IV Criterion A1 for PTSD, which requires that the event “involved actual or threatened death or serious injury, or a threat to the physical integrity of self or others” (APA,
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1994, p. 427). Interrater reliability was in the acceptable range (j = .77), and all discrepancies were resolved through consensus discussion. As noted previously, only participants whose index events were classified as meeting DSM-IV Criterion A1 were included in analyses. On the basis of participants’ reports of their worst events as indicated on the LEC, we used two types of information to classify participants for study analyses. First, we classified traumas as either interpersonal, which were defined as those perpetrated by another person (i.e., physical or sexual assault with or without a weapon, other unwanted sexual experience), or noninterpersonal, which were defined as those not perpetrated by another person (i.e., exposure to natural disaster or fire; serious transportation or other accident; life-threatening illness or injury; and the sudden, violent, or unexpected death of a loved one). From the sample of individuals whose events met Criterion A1 (N = 334), some participants identified index events that did not clearly fit into either category (i.e., participants who selected “other” from the list of traumatic events), and these participants’ trauma types were recoded as missing. Thus, the sample included 68 individuals with interpersonal trauma (20.36% of the sample), 255 with noninterpersonal trauma (76.35%), and 11 with missing values (3.29%). Second, we grouped participants based on their reported level of exposure to their index event. Specifically, for each LEC event category, participants chose from five event exposure options: happened to me, witnessed it, learned about it, not sure, or doesn’t apply. Utilizing LEC responses, we classified participants into two exposure levels: direct (i.e., happened to me) and indirect (i.e., witnessed it or learned about it). Participants whose index event was not classifiable as direct or indirect (i.e., they did not select an exposure level or selected unsure or doesn’t apply) were recoded to indicate “missing” values on the exposure level variable. Thus, the sample included 205 individuals with direct
687 exposure (61.38%), 96 with indirect exposure (28.74%), and 33 with missing values (9.88%). Among participants who experienced direct trauma, 44 (21.50%) experienced interpersonal trauma, 155 (75.60%) experienced noninterpersonal trauma, and six (2.90%) had missing data. Among participants with indirect trauma exposure, 17 (17.71%) experienced interpersonal trauma, 76 (79.17%) experienced noninterpersonal trauma, and 3 (3.13%) had missing data. PTSD Symptoms. We assessed PTSD symptom severity with the PTSD Checklist – Specific version (PCL-S; Weathers, Litz, Herman, Huska, & Keane, 1993). The PCL-S asks respondents to rate how much they have been bothered by each of the 17 DSM-IV PTSD symptoms during the past month, using a 5-point scale (1 = not at all through 5 = extremely). Participants were asked to base PCL-S responses on their LEC specified index event. The PCL-S is a widely used and well-validated self-report measure with good psychometric properties (McDonald & Calhoun, 2010; Wilkins, Lang, & Norman, 2011). In the current sample, internal consistency for the total score on PCL-S was good (a = .93). Although not used in subsequent analyses, mean total score on the PCL-S was 29.83 (SD = 12.40). Also, 14.37% of participants (n = 48) scored at or above a cutoff score of 44, which indicates a probable PTSD diagnosis among treatment-seeking trauma survivors (Ruggiero, Del Ben, Scotti, & Rabalais, 2003; Terhakopian, Sinaii, Engel, Schnurr, & Hoge, 2008). Further, 35.90% (n = 120) met criteria for PTSD according to the DSM-IV diagnostic scoring rule for the PCL-S, which involves treating PCL-S items rated moderately or higher as a symptom endorsed and then following DSM-IV diagnostic requirements (i.e., one reexperiencing symptom, three avoidance and numbing symptoms, two hyperarousal symptoms). On the basis of preliminary analyses of the factor structure of the PCL-S in this sample (Davis et al., in press), as well as on past literature (e.g., Elhai & Palmieri, 2011), we used a five-factor model of PTSD
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symptoms in our analyses. The five-factor model not only separates avoidance and numbing symptoms, but also separates hyperarousal symptoms into dysphoric arousal and anxious arousal clusters. Thus, PCL-S items were summed to create total scores for each of five symptom clusters: reexperiencing, avoidance, numbing, dysphoric arousal, and anxious arousal. Internal consistencies for the five clusters were all in the acceptable range in the current sample (a values ranged from .74 to .87).
RESULTS
Preliminary Analyses Analyses were conducted in Mplus version 6.11 (Muthen & Muthen, 19982010). Covariance coverage for all pairwise variables ranged from 96% to 100%. Missing data were minimal, and missing value pattern analyses in SPSS version 20 revealed that no variables had more than 5% of values missing. Missing data were handled using full information maximum likelihood (FIML) in all study analyses. Because not all of our variables were normally distributed, we used a robust maximum likelihood estimator (Muthen & Asparouhov, 2002). Descriptive statistics for all observed variables, including means, standard deviations, skewness, and kurtosis, are found in Table 1, along with intercorrelations between all study variables. Due to significant bivariate associations between some variables and gender, gender (0 = male; 1 = female) was included as a covariate in subsequent analyses. Study Aim 1. First, we ran a path analytic model to investigate the relationships between PTSD symptom clusters and both facets of ACS (i.e., FAD and pain tolerance). We modeled both outcome variables (i.e., FAD and pain tolerance) simultaneously, using gender and PTSD symptom clusters as predictor variables. A graphical depiction of the model, including standardized betas and significance values, is
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shown in Figure 1. Supplemental information, including standard errors and unstandardized model results, is located online in Table S1. As anticipated, several PTSD symptom clusters were significantly associated with facets of ACS. However, contrary to hypotheses that relationships between all symptom clusters and ACS would emerge, there was evidence of discriminant relations between symptom clusters and each facet of ACS. Specifically, the anxious arousal cluster was negatively associated with only the FAD facet of ACS (standardized b = 0.20, p < .01), whereas the numbing symptom cluster was positively associated with only the pain tolerance facet of ACS (standardized b = 0.24, p < .01). Contrary to our prediction and to past literature investigating ACS and PTSD symptoms (i.e., Bryan & Anestis, 2011), there was no relationship between the reexperiencing symptom cluster and either facet of ACS. Also contrary to hypotheses predicting the negative association between the dysphoric arousal and avoidance clusters and ACS, neither of these clusters was associated with either facet of ACS. Gender was negatively associated with both FAD and pain tolerance, indicating that males in the sample had higher FAD and pain tolerance scores. To investigate the discrepancy between our results and the previously described relationship between reexperiencing symptoms and ACS, we replicated analyses conducted by Bryan and Anestis (2011), utilizing their five-item version of ACS as our outcome variable. The predictor variables in this model were identical to our prior analysis. As can be seen in Table 2, the relationship between the numbing symptom cluster and ACS approached statistical significance (standardized b = 0.17, p = .05); however, no other PTSD symptom cluster was associated with ACS. Study Aim 2. Lastly, to test the relationships between trauma type and trauma exposure level and the facets of ACS, we conducted another path analytic model, regressing FAD and pain tolerance onto binary predictor variables that represented
1 .73* .51* .52* .53* .14* .09 .02 .07 .11 .10 324 8.98 4.19 1.24 0.94
1. Reexperiencing 2. Avoidance 3. Numbing 4. Dysphoric arousal 5. Anxious arousal 6. FAD 7. Pain tolerance 8. 5-item ACS 9. Exposure level 10. Trauma type 11. Gender n M SD Skewness Kurtosis 1 .57* .53* .45* .14* .11* .01 .09 .19* .12* 325 3.98 2.15 1.02 0.08
2
1 .75* .45* .01 .20* .13* .09 .18* .02 320 7.87 3.75 1.39 1.09
3
1 .51* .02 .13* .08 .08 .18* .01 326 5.55 3.15 1.27 0.69
4
1 .19* .08 .03 .11 .20* .10* 325 4.53 2.12 1.31 0.71
5
1 .31* .60* .02 .02 .21* 325 14.30 7.02 0.01 0.54
6
1 .69* .07 .12* .23* 332 4.48 2.50 0.25 1.01
7
1 .02 .11* .38* 331 9.97 4.31 0.02 0.34
8
1 .04 .16* 301 .32 .47 0.78 1.40
9
1 .03 323 .79 .41 1.43 0.04
10
1 334 .72 .44 0.99 1.02
11
Note. Intercorrelations run using full information maximum likelihood (FIML) in Mplus. FAD, fearlessness about death; ACS, acquired capability for suicide; 5-item ACS = measure combining FAD and pain tolerance. Reexperiencing, avoidance, numbing, dysphoric arousal, and anxious arousal variables refer to total score for symptom cluster. Trauma exposure level coded 0 = direct experience, 1 = indirect experience. Trauma type coded 0 = interpersonal trauma, 1 = noninterpersonal trauma. Gender coded 0 = male, 1 = female. *p ≤ .05.
1
Variable
Means, Standard Deviations, and Intercorrelations for All Study Variables
TABLE 1
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Re-experiencing
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-.02 -.01
Avoidance
-.12 .04
.11 Numbing
.24*
Fearlessness about death
.08 Dysphoric Arousal
.30*
-.07 Pain tolerance
Anxious Arousal
-.20* .03 -.18*
Gender (0 = male; 1= female)
-.24*
Figure 1. Path analytic model depicting the relationships between study variables. Parameters in the model represent standardized coefficients (StdYX in Mplus). Dashed lines indicate paths that were not significant. Correlations between predictor variables were also estimated but are not depicted. *p < .01
group membership for trauma type and exposure level, based on the aforementioned coding process using participants’ responses on the LEC (i.e., trauma type: 0 = interpersonal trauma, 1 = noninterpersonal trauma; trauma exposure: 0 = direct trauma, 1 = indirect trauma), including gender as covariate. Contrary to hypotheses, results from this model indicated that neither trauma type nor trauma exposure level was associated with either facet of ACS (see Table 3).
DISCUSSION
The current study applied the framework of the IPTS to explore potential mechanisms underlying the relationship between aspects of PTSD (i.e., symptoms, trauma type, and level of exposure) and fatal
and nonfatal suicide attempts. Contrary to hypotheses, no significant associations emerged between reexperiencing symptoms and ACS components, despite findings in previous research (Bryan & Anestis, 2011) and efforts to replicate these previous findings by utilizing the same measure of ACS. Therefore, our results do not seem to support the hypothesis that reexperiencing symptoms function to increase ACS by allowing individuals to relive past painful and/or fear-inducing experiences. In fact, when considering the bivariate associations between reexperiencing and facets of ACS, there was actually a modest negative correlation between this symptom cluster and FAD, although this effect was no longer statistically significant within the multivariate model. Of note, the current sample was demographically different (e.g., civilian,
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TABLE 2
Results of Five-Item ACS Measure Path Analytic Model Parameter Estimated 5-item ACS on Reexperiencing Avoidance Numbing Dysphoric arousal Anxious arousal Gender Reexperiencing with Avoidance Numbing Dysphoric arousal Anxious arousal Gender Avoidance with Numbing Dysphoric arousal Anxious arousal Gender Numbing with Dysphoric arousal Anxious arousal Gender Dysphoric arousal with Anxious arousal Gender Anxious arousal with Gender
Unstd. B
SE B
StdYX b
p
0.07 0.06 0.19 0.01 0.09 3.59
0.09 0.16 0.10 0.12 0.14 0.49
0.07 0.03 0.17 0.01 0.05 0.37
.39 .71 .05 .94 .50
Suicide and Life-Threatening Behavior 44 (6) December 2014 © 2014 The American Association of Suicidology DOI: 10.1111/sltb.12098
PTSD Symptom Clusters Are Differentially Associated with Components of the Acquired Capability for Suicide KELLY L. ZUROMSKI, BS, MARGARET T. DAVIS, MS, TRACY K. WITTE, PHD, FRANK WEATHERS, PHD, AND CHRISTY BLEVINS, MS
Previous research has established the link between posttraumatic stress disorder (PTSD) and suicidal behavior. In the current study, constructs proposed to explain this relationship were examined, applying the framework of the interpersonal-psychological theory of suicide (IPTS). Relationships between acquired capability for suicide (ACS; i.e., fearlessness about death [FAD] and pain tolerance) and specific PTSD symptom clusters were explored. In a sample of 334 trauma-exposed undergraduates, anxious arousal and FAD were negatively associated, and numbing and pain tolerance were positively associated. Results establish a foundation for investigating the role of ACS in understanding observed relationships between suicidal behavior and PTSD symptoms. The relationship between posttraumatic stress disorder (PTSD) and suicidal behavior is well established (Nock et al., 2009; Panagioti, Gooding, & Tarrier, 2009, 2012). Specifically, studies comparing individuals with PTSD to trauma-exposed but healthy controls have reported higher risk of suicide ideation (Krysinska & Lester, 2010; Panagioti et al., 2012), sucide attempts (Davidson, Hughes, Blazer, & George, 1991; Kessler, Borges, & Walters, 1999), and death by suicide (Gradus et al., 2010). These findings suggest that something about PTSD, either at the syndrome or symptom cluster level, confers risk of suicidal behavior. However, understanding of this increased risk is limited by (1) the predominantly atheoretical nature of prior KELLY L. ZUROMSKI, MARGARET T. DAVIS, TRACY K. WITTE, FRANK WEATHERS and CHRISTY BLEVINS, Department of Psychology, Auburn University, Auburn, AL, USA. Address correspondence to Tracy K. Witte, Department of Psychology, Auburn University, 226 Thach Hall, Auburn, AL 36849-5214; E-mail: [email protected]
research (Panagioti et al., 2009), and (2) a focus on PTSD diagnostic status or overall symptom severity rather than on specific PTSD symptom clusters or other potentially relevant trauma-related factors (e.g., trauma type or level of exposure). In the current study, we used the interpersonalpsychological theory of suicide (IPTS; Joiner, 2005; Van Orden et al., 2010) as a framework to address these limitations and investigate potential mechanisms underlying the relationship between PTSD, or trauma exposure more broadly, and suicide attempts. The IPTS identifies two constructs as proximal causes of suicidal desire: thwarted belongingness (i.e., social isolation) and perceived burdensomeness (i.e., feeling that one is a liability to others). However, the IPTS specifies that an individual must possess not only suicidal desire, but also a lowered fear of death and elevated physical pain tolerance, to engage in the fearsome and painful act of lethal self-injury. These two components constitute the acquired capability for suicide (ACS; Van Orden
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et al., 2010). Specifically, the IPTS proposes that suicidal desire develops into suicidal intent only in the presence of fearlessness about death (FAD) and that suicidal intent develops into a lethal suicide attempt only in the presence of pain tolerance (i.e., individuals with higher pain tolerance will be able to make more lethal attempts). Without FAD and pain tolerance, the IPTS proposes that an individual will not be capable of enacting self-harm even if he or she has a strong desire for suicide (Joiner, 2005; Van Orden et al., 2010). This capability is posited to develop and occur independently of one’s desire for suicide; thus, an individual could have an elevated ACS even if he or she does not endorse suicidal ideation (Joiner, 2005; Smith & Cukrowicz, 2010; Van Orden et al., 2010). Past research on ACS has demonstrated that FAD is associated with suicidal intent among suicide attempters (Ribeiro et al., 2014). Further, both FAD and pain tolerance can differentiate suicide attempters from ideators (Smith, Cukrowicz, Poindexter, Hobson, & Cohen, 2010). ACS may be especially relevant in explaining the link between trauma exposure and suicide attempts. Specifically, the capability for suicide is proposed to develop through repeated exposure to various life events or experiences that are painful and/ or fear-inducing. Joiner (2005) and Van Orden et al. (2010) suggested that repeated exposure to painful and/or fear-inducing stimuli (e.g., trauma exposure) results in habituation to fear of death and/or physical pain, which makes an individual more capable of suicidal behavior. In fact, a growing literature suggests that traumatic experiences including combat exposure (Kang & Bullman, 2008), childhood maltreatment (Beautrais, 2001), and exposure to suicidality in others (Insel & Gould, 2008) are all linked to suicidal behavior, and Van Orden et al. (2010) suggested that these experiences function as painful and/or fear-inducing events that can contribute to ACS. As such, the main focus of our study was to use the IPTS as a theoretical framework to
683 examine the relationship between trauma exposure and both facets of ACS. Two qualitative studies have suggested that the IPTS provides a useful framework for examining suicidal behavior among trauma-exposed military samples (Anestis, Bryan, Cornette, & Joiner, 2009; Brenner et al., 2008). In addition, regarding ACS specifically, research has demonstrated an association between ACS and trauma exposure as well as severity of PTSD symptoms (Bryan, Cukrowicz, West, & Morrow, 2010; Bryan, Hernandez, Allison, & Clemans, 2012). Nevertheless, these studies are limited in that they only considered overall PTSD symptom severity and did not evaluate specific PTSD symptom clusters. This approach is problematic given the considerable evidence that PTSD is a multifaceted construct comprising as many as five distinct, yet related, symptom clusters (Elhai et al., 2011). In light of the multifaceted nature of PTSD, some researchers have explored the relationships between symptom clusters and ACS. Within the framework of the IPTS, Selby et al. (2010) emphasized the centrality of reexperiencing symptoms, arguing that individuals endorsing these symptoms are mentally rehearsing past exposure to past painful and/or fear-inducing traumatic stimuli, which could contribute to both facets of ACS. In support of this argument, Bryan and Anestis (2011) found a significant relationship between ACS and the reexperiencing symptom cluster in a sample of deployed military personnel. However, this study did not investigate other symptom clusters besides reexperiencing. Further, the two facets of ACS were combined for analyses, making it impossible to explore discriminant relations between reexperiencing and FAD and pain tolerance. Moreover, no studies have employed the use of the fivefactor dysphoric arousal model of PTSD (Elhai et al., 2011) in investigating the relationship between PTSD symptoms and ACS. This model separates hyperarousal into dysphoric and anxious arousal clusters, and it is quite possible that differential
684 relationships may exist between the separate arousal categories and ACS. Outside the framework of the IPTS, research examining the relationship between trauma exposure and suicidal behavior offers evidence of potential relationships between PTSD symptom clusters and ACS. This body of research is limited, however, in that the existing studies (e.g., Ben-Ya’acov & Amir, 2004; Tarrier & Gregg, 2004) use the Diagnostic and Statistical Manual (DSM-IV; American Psychiatric Association [APA], 1994) model of PTSD symptom structure. The most problematic aspect of the DSM-IV model is that it combines avoidance and numbing symptoms into one cluster, despite factor analytic research indicating that avoidance and numbing symptoms represent distinct clusters (see Asmundson, Stapleton, & Taylor, 2004, for a review). Previous research suggests that the separation of avoidance and numbing symptoms is important due to their etiological differences. For instance, Litz (1992) argued that numbing symptoms arise as a result of habituation to chronic emotional arousal experience after repeated exposure to trauma cues, whereas avoidance symptoms are the result of conscious coping processes (Foa, Zinbarg, & Rothbaum, 1992). Although some numbing symptoms likely reflect interpersonal disruption, and thus may relate more directly to suicidal ideation (e.g., Davis, Witte, Weathers, & Blevins, in press), it seems that other numbing symptoms may be relevant to ACS. For instance, previous pain research has demonstrated decreased pain sensitivity following repeated painful stimulation (i.e., stress-induced analgesia) in individuals with PTSD compared with controls (e.g., Strigo et al., 2010; Van de Kolk, Pitman, & Orr, 1989), and this stress-induced analgesia is thought to be one manifestation of numbing symptoms (Foa et al., 1992). Considered within the framework of the IPTS, both components of ACS (i.e., FAD and heightened pain tolerance) are proposed to develop through the same process of habituation following
PTSD SYMPTOMS
AND
ACQUIRED CAPABILITY
repeated exposure to painful and/or fearinducing stimuli (Van Orden et al., 2010). Because of the similar etiology of numbing symptoms and ACS, numbing symptoms may be more strongly related to facets of ACS than avoidance symptoms. On the contrary, presence of avoidance symptoms may be more reflective of lower levels of ACS, if individuals are likely to avoid trauma-related stimuli (e.g., Foa et al., 1992) that would otherwise result in habituation to fear of death and pain (Litz, 1992). Whereas numbing symptoms are conceptualized as developing in response to chronic hyperarousal (Litz, 1992) and seem consistent with increased ACS, experience of hyperarousal symptoms (e.g., hypervigilance, exaggerated startle response) may function similarly to avoidance symptoms and also be negatively associated with ACS. Hyperarousal symptoms reflect impaired fear inhibition (Jovanovic et al., 2010), which seems to align theoretically with the FAD facet. Specifically, individuals who experience hyperarousal symptoms have not habituated to exposure to trauma-related stimuli and thus have lower levels of fearlessness, which may also relate to fear of death-related stimuli (i.e., lower FAD). However, existing research examining the relationship between hyperarousal symptoms and suicide attempts (e.g., Ben-Ya’acov & Amir, 2004; Tarrier & Gregg, 2004) is methodologically limited (e.g., combining PTSD symptoms in analyses; small sample sizes), and thus, it is difficult to evaluate these findings within the framework of the IPTS. While some research within the IPTS field has attempted to clarify the relationship between PTSD symptom clusters (i.e., reexperiencing) and ACS, other variables related to trauma exposure, such as trauma type and level of exposure, remain understudied. Past research within the trauma field has demonstrated that history of suicide attempts is more strongly associated with trauma exposure involving rape or being threatened with a weapon compared with other types of traumatic events (Floen
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& Elklit, 2007). This research suggests that interpersonal trauma (i.e., traumas perpetrated by another person, such as physical/ sexual assault) is more associated with suicide attempt and thus may be more strongly associated with ACS than noninterpersonal trauma (i.e., traumas not perpetrated by another person, such as motor vehicle accidents or natural disasters). Although no studies have directly compared trauma types in the context of ACS, research by Fillingim and Edwards (2005) demonstrated that history of childhood abuse is associated with decreased sensitivity to experimentally induced pain compared with healthy controls, which seems consistent with the heightened physical pain tolerance facet of ACS, and may provide indirect evidence of increased ACS among individuals exposed to interpersonal trauma. Furthermore, level of exposure to trauma (i.e., directly experiencing a traumatic event versus witnessing it or learning that it happened to a loved one) and suicidal behavior has not been addressed in past literature, although this distinction is an important aspect of Criterion A (stressor criterion) for PTSD (APA, 1994). Because the IPTS suggests that firsthand exposure to painful and/or fear-inducing events contributes to ACS (Joiner, 2005), direct experience of trauma may contribute more to ACS, and subsequently, to one’s risk of suicidal behavior. Thus, this component of traumatic experience was also explored in the current study. The current study had two main aims. The primary aim was to evaluate theory-driven hypotheses related to the relationships between PTSD symptom clusters and components of ACS. First, we hypothesized that both ACS facets (i.e., FAD and pain tolerance) would be positively associated with the reexperiencing symptom cluster, consistent with past research. Second, we predicted that the numbing symptom cluster would be positively related to both ACS facets, consistent with trauma literature on habituation to trauma-related cues resulting in blunted
685 responses. Third, we hypothesized that the avoidance symptom cluster would be negatively related to both ACS facets. Fourth, we predicted that both dysphoric and anxious arousal symptom clusters would be negatively associated with both ACS facets, considering the fear-based etiology of hyperarousal symptoms. Our secondary aim was to investigate the relationship between other features of trauma exposure and ACS. Related to trauma type, we predicted that experience of interpersonal trauma, compared with noninterpersonal trauma, would be positively associated with both ACS facets, consistent with past research on interpersonal trauma and risk of suicide attempts. Lastly, consistent with the emphasis the IPTS places on firsthand experience of painful and/or fear-inducing events and ACS, we hypothesized that direct experience of trauma (as opposed to witnessing or hearing about a traumatic event) would be positively associated with both ACS facets.
METHOD
Participants and Procedure Participants were undergraduate students enrolled in psychology courses at a large public university in the southeastern United States. After approval from the university’s institutional review board, individuals who self-identified as having experienced a very stressful life event (N = 512) were recruited using an online pool of undergraduate psychology students. This data set was also utilized in another recent study on traumatic life events (i.e., Davis et al., in press); however, although there is some overlap in the measures used in the current study and Davis et al., the study aims and primary analyses are unique. Participants completed a battery of computerized self-report questionnaires during proctored data collection sessions. Only participants whose designated worst event met DSM-IV Criterion A1 were included in
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PTSD SYMPTOMS
analyses. The final sample included 334 individuals (72.2% female), whose mean age was 19.65 (SD = 3.30; range from 17 to 54). Most participants were non-Latino White/European origin (79.3%); 12.6% were Black; 3.6% were Latino/Hispanic; 3% were Asian American/Pacific Islander; 1.5% identified as multiracial or other. Measures Fearlessness About Death. The Acquired Capability for Suicide Scale (ACSS; Van Orden, Witte, Gordon, Bender, & Joiner, 2008) was originally developed as a 20-item self-report measure to assess both FAD and pain insensitivity. However, a recent psychometric investigation of the ACSS supports the use of a 7-item subscale of the ACSS to assess FAD (ACSS-FAD; Ribeiro et al., 2014). Several other investigations have found discriminant relations between various constructs and the ACSSFAD and pain tolerance (Witte, Correia, & Angarano, 2013; Witte, Gordon, Smith, & Van Orden, 2012). In the current study, although we administered the full ACSS, the ACSS-FAD subscale was utilized as a measure of FAD. Items including I am not at all afraid to die and The fact that I am going to die does not affect me were rated on a 5-point scale, with higher scores indicating greater FAD. Internal consistency for the 7-item ACSS in the current sample was adequate (a = .83). Pain Tolerance. Pain tolerance was assessed using one item from the 20-item version of the Acquired Capability for Suicide Scale (i.e., I can tolerate a lot more pain than most people; ACSS; Van Orden et al., 2008) and one from the Discomfort Intolerance Scale (i.e., I can tolerate a great deal of physical discomfort; DIS; Schmidt, Richey, & Fitzpatrick, 2006). Similar items have been shown to load strongly onto a pain tolerance factor in undergraduate and clinical samples (Schmidt et al., 2006). Both items were rated on 5-point scales and coded such that higher scores reflected higher pain tolerance. Internal consistency
AND
ACQUIRED CAPABILITY
for this measure of pain tolerance was adequate (a = .85). Combined Measure of Acquired Capability. In an attempt to replicate previous findings, we also derived a total score for the 5-item subset of the ACSS administered by Bryan and Anestis (2011), which conflates FAD and pain tolerance and includes some items that do not clearly indicate either of these constructs. This measure contained the following items: (1) The sight of a dead body is horrifying to me; (2) I like watching aggressive contact in sports games; (3) I can tolerate a lot more pain than most people; (4) I am not at all afraid to die; and (5) Things that scare most people do not scare me. Of these five items, only one (i.e., item (4)) is included in the Ribeiro et al. (2014) FAD subscale. These items were rated on a 5point scale, with higher scores indicating higher levels of ACS. Internal consistency for this measure in the current sample was .60, which is consistent with previous reports using this scale (Bryan & Anestis, 2011) and reflects the diverse content of the five items. Trauma Type and Exposure Level. We assessed trauma event type and exposure level with the Life Events Checklist (LEC), the self-report trauma section of the Clinician-Administered PTSD Scale (CAPS; Blake et al., 1995; Weathers, Keane, & Davidson, 2001). The LEC assesses exposure to 17 types of traumatic events (e.g., physical assault, transportation accident) and has demonstrated sound psychometric properties (Gray, Litz, Hsu, & Lombardo, 2004). As described by Davis et al. (in press), following completion of the LEC, participants indicated their worst traumatic event, wrote a brief narrative description of it, and used it as the basis for reporting PTSD symptoms. A team of graduate students supervised by the fourth author (FW) coded these narrative descriptions to determine whether the index event met DSM-IV Criterion A1 for PTSD, which requires that the event “involved actual or threatened death or serious injury, or a threat to the physical integrity of self or others” (APA,
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1994, p. 427). Interrater reliability was in the acceptable range (j = .77), and all discrepancies were resolved through consensus discussion. As noted previously, only participants whose index events were classified as meeting DSM-IV Criterion A1 were included in analyses. On the basis of participants’ reports of their worst events as indicated on the LEC, we used two types of information to classify participants for study analyses. First, we classified traumas as either interpersonal, which were defined as those perpetrated by another person (i.e., physical or sexual assault with or without a weapon, other unwanted sexual experience), or noninterpersonal, which were defined as those not perpetrated by another person (i.e., exposure to natural disaster or fire; serious transportation or other accident; life-threatening illness or injury; and the sudden, violent, or unexpected death of a loved one). From the sample of individuals whose events met Criterion A1 (N = 334), some participants identified index events that did not clearly fit into either category (i.e., participants who selected “other” from the list of traumatic events), and these participants’ trauma types were recoded as missing. Thus, the sample included 68 individuals with interpersonal trauma (20.36% of the sample), 255 with noninterpersonal trauma (76.35%), and 11 with missing values (3.29%). Second, we grouped participants based on their reported level of exposure to their index event. Specifically, for each LEC event category, participants chose from five event exposure options: happened to me, witnessed it, learned about it, not sure, or doesn’t apply. Utilizing LEC responses, we classified participants into two exposure levels: direct (i.e., happened to me) and indirect (i.e., witnessed it or learned about it). Participants whose index event was not classifiable as direct or indirect (i.e., they did not select an exposure level or selected unsure or doesn’t apply) were recoded to indicate “missing” values on the exposure level variable. Thus, the sample included 205 individuals with direct
687 exposure (61.38%), 96 with indirect exposure (28.74%), and 33 with missing values (9.88%). Among participants who experienced direct trauma, 44 (21.50%) experienced interpersonal trauma, 155 (75.60%) experienced noninterpersonal trauma, and six (2.90%) had missing data. Among participants with indirect trauma exposure, 17 (17.71%) experienced interpersonal trauma, 76 (79.17%) experienced noninterpersonal trauma, and 3 (3.13%) had missing data. PTSD Symptoms. We assessed PTSD symptom severity with the PTSD Checklist – Specific version (PCL-S; Weathers, Litz, Herman, Huska, & Keane, 1993). The PCL-S asks respondents to rate how much they have been bothered by each of the 17 DSM-IV PTSD symptoms during the past month, using a 5-point scale (1 = not at all through 5 = extremely). Participants were asked to base PCL-S responses on their LEC specified index event. The PCL-S is a widely used and well-validated self-report measure with good psychometric properties (McDonald & Calhoun, 2010; Wilkins, Lang, & Norman, 2011). In the current sample, internal consistency for the total score on PCL-S was good (a = .93). Although not used in subsequent analyses, mean total score on the PCL-S was 29.83 (SD = 12.40). Also, 14.37% of participants (n = 48) scored at or above a cutoff score of 44, which indicates a probable PTSD diagnosis among treatment-seeking trauma survivors (Ruggiero, Del Ben, Scotti, & Rabalais, 2003; Terhakopian, Sinaii, Engel, Schnurr, & Hoge, 2008). Further, 35.90% (n = 120) met criteria for PTSD according to the DSM-IV diagnostic scoring rule for the PCL-S, which involves treating PCL-S items rated moderately or higher as a symptom endorsed and then following DSM-IV diagnostic requirements (i.e., one reexperiencing symptom, three avoidance and numbing symptoms, two hyperarousal symptoms). On the basis of preliminary analyses of the factor structure of the PCL-S in this sample (Davis et al., in press), as well as on past literature (e.g., Elhai & Palmieri, 2011), we used a five-factor model of PTSD
688
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symptoms in our analyses. The five-factor model not only separates avoidance and numbing symptoms, but also separates hyperarousal symptoms into dysphoric arousal and anxious arousal clusters. Thus, PCL-S items were summed to create total scores for each of five symptom clusters: reexperiencing, avoidance, numbing, dysphoric arousal, and anxious arousal. Internal consistencies for the five clusters were all in the acceptable range in the current sample (a values ranged from .74 to .87).
RESULTS
Preliminary Analyses Analyses were conducted in Mplus version 6.11 (Muthen & Muthen, 19982010). Covariance coverage for all pairwise variables ranged from 96% to 100%. Missing data were minimal, and missing value pattern analyses in SPSS version 20 revealed that no variables had more than 5% of values missing. Missing data were handled using full information maximum likelihood (FIML) in all study analyses. Because not all of our variables were normally distributed, we used a robust maximum likelihood estimator (Muthen & Asparouhov, 2002). Descriptive statistics for all observed variables, including means, standard deviations, skewness, and kurtosis, are found in Table 1, along with intercorrelations between all study variables. Due to significant bivariate associations between some variables and gender, gender (0 = male; 1 = female) was included as a covariate in subsequent analyses. Study Aim 1. First, we ran a path analytic model to investigate the relationships between PTSD symptom clusters and both facets of ACS (i.e., FAD and pain tolerance). We modeled both outcome variables (i.e., FAD and pain tolerance) simultaneously, using gender and PTSD symptom clusters as predictor variables. A graphical depiction of the model, including standardized betas and significance values, is
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ACQUIRED CAPABILITY
shown in Figure 1. Supplemental information, including standard errors and unstandardized model results, is located online in Table S1. As anticipated, several PTSD symptom clusters were significantly associated with facets of ACS. However, contrary to hypotheses that relationships between all symptom clusters and ACS would emerge, there was evidence of discriminant relations between symptom clusters and each facet of ACS. Specifically, the anxious arousal cluster was negatively associated with only the FAD facet of ACS (standardized b = 0.20, p < .01), whereas the numbing symptom cluster was positively associated with only the pain tolerance facet of ACS (standardized b = 0.24, p < .01). Contrary to our prediction and to past literature investigating ACS and PTSD symptoms (i.e., Bryan & Anestis, 2011), there was no relationship between the reexperiencing symptom cluster and either facet of ACS. Also contrary to hypotheses predicting the negative association between the dysphoric arousal and avoidance clusters and ACS, neither of these clusters was associated with either facet of ACS. Gender was negatively associated with both FAD and pain tolerance, indicating that males in the sample had higher FAD and pain tolerance scores. To investigate the discrepancy between our results and the previously described relationship between reexperiencing symptoms and ACS, we replicated analyses conducted by Bryan and Anestis (2011), utilizing their five-item version of ACS as our outcome variable. The predictor variables in this model were identical to our prior analysis. As can be seen in Table 2, the relationship between the numbing symptom cluster and ACS approached statistical significance (standardized b = 0.17, p = .05); however, no other PTSD symptom cluster was associated with ACS. Study Aim 2. Lastly, to test the relationships between trauma type and trauma exposure level and the facets of ACS, we conducted another path analytic model, regressing FAD and pain tolerance onto binary predictor variables that represented
1 .73* .51* .52* .53* .14* .09 .02 .07 .11 .10 324 8.98 4.19 1.24 0.94
1. Reexperiencing 2. Avoidance 3. Numbing 4. Dysphoric arousal 5. Anxious arousal 6. FAD 7. Pain tolerance 8. 5-item ACS 9. Exposure level 10. Trauma type 11. Gender n M SD Skewness Kurtosis 1 .57* .53* .45* .14* .11* .01 .09 .19* .12* 325 3.98 2.15 1.02 0.08
2
1 .75* .45* .01 .20* .13* .09 .18* .02 320 7.87 3.75 1.39 1.09
3
1 .51* .02 .13* .08 .08 .18* .01 326 5.55 3.15 1.27 0.69
4
1 .19* .08 .03 .11 .20* .10* 325 4.53 2.12 1.31 0.71
5
1 .31* .60* .02 .02 .21* 325 14.30 7.02 0.01 0.54
6
1 .69* .07 .12* .23* 332 4.48 2.50 0.25 1.01
7
1 .02 .11* .38* 331 9.97 4.31 0.02 0.34
8
1 .04 .16* 301 .32 .47 0.78 1.40
9
1 .03 323 .79 .41 1.43 0.04
10
1 334 .72 .44 0.99 1.02
11
Note. Intercorrelations run using full information maximum likelihood (FIML) in Mplus. FAD, fearlessness about death; ACS, acquired capability for suicide; 5-item ACS = measure combining FAD and pain tolerance. Reexperiencing, avoidance, numbing, dysphoric arousal, and anxious arousal variables refer to total score for symptom cluster. Trauma exposure level coded 0 = direct experience, 1 = indirect experience. Trauma type coded 0 = interpersonal trauma, 1 = noninterpersonal trauma. Gender coded 0 = male, 1 = female. *p ≤ .05.
1
Variable
Means, Standard Deviations, and Intercorrelations for All Study Variables
TABLE 1
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690
PTSD SYMPTOMS
Re-experiencing
AND
ACQUIRED CAPABILITY
-.02 -.01
Avoidance
-.12 .04
.11 Numbing
.24*
Fearlessness about death
.08 Dysphoric Arousal
.30*
-.07 Pain tolerance
Anxious Arousal
-.20* .03 -.18*
Gender (0 = male; 1= female)
-.24*
Figure 1. Path analytic model depicting the relationships between study variables. Parameters in the model represent standardized coefficients (StdYX in Mplus). Dashed lines indicate paths that were not significant. Correlations between predictor variables were also estimated but are not depicted. *p < .01
group membership for trauma type and exposure level, based on the aforementioned coding process using participants’ responses on the LEC (i.e., trauma type: 0 = interpersonal trauma, 1 = noninterpersonal trauma; trauma exposure: 0 = direct trauma, 1 = indirect trauma), including gender as covariate. Contrary to hypotheses, results from this model indicated that neither trauma type nor trauma exposure level was associated with either facet of ACS (see Table 3).
DISCUSSION
The current study applied the framework of the IPTS to explore potential mechanisms underlying the relationship between aspects of PTSD (i.e., symptoms, trauma type, and level of exposure) and fatal
and nonfatal suicide attempts. Contrary to hypotheses, no significant associations emerged between reexperiencing symptoms and ACS components, despite findings in previous research (Bryan & Anestis, 2011) and efforts to replicate these previous findings by utilizing the same measure of ACS. Therefore, our results do not seem to support the hypothesis that reexperiencing symptoms function to increase ACS by allowing individuals to relive past painful and/or fear-inducing experiences. In fact, when considering the bivariate associations between reexperiencing and facets of ACS, there was actually a modest negative correlation between this symptom cluster and FAD, although this effect was no longer statistically significant within the multivariate model. Of note, the current sample was demographically different (e.g., civilian,
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TABLE 2
Results of Five-Item ACS Measure Path Analytic Model Parameter Estimated 5-item ACS on Reexperiencing Avoidance Numbing Dysphoric arousal Anxious arousal Gender Reexperiencing with Avoidance Numbing Dysphoric arousal Anxious arousal Gender Avoidance with Numbing Dysphoric arousal Anxious arousal Gender Numbing with Dysphoric arousal Anxious arousal Gender Dysphoric arousal with Anxious arousal Gender Anxious arousal with Gender
Unstd. B
SE B
StdYX b
p
0.07 0.06 0.19 0.01 0.09 3.59
0.09 0.16 0.10 0.12 0.14 0.49
0.07 0.03 0.17 0.01 0.05 0.37
.39 .71 .05 .94 .50
