Cognitive Therapy and Research

, Volume 40, Issue 2, pp 173–178 | Cite as

Shared Cognitive Features of Posttraumatic Cognitions and Obsessive–Compulsive Symptoms

Brief Report

Abstract

Obsessive–compulsive disorder (OCD) and posttraumatic stress disorder (PTSD) frequently co-occur. However, the shared features of these conditions have been under-examined. Evaluation of the common aspects of posttraumatic and obsessive–compulsive (OC) symptoms could improve treatment responsivity for individuals with comorbid PTSD and OCD, for whom outcome is typically poorer than for those with either disorder alone. This study examined intolerance of uncertainty, inflated responsibility, and a global measure of posttraumatic cognitions as potential shared cognitive constructs that moderate distress associated with OC symptoms. A total of 211 undergraduate students reporting significant trauma histories participated. All participants completed measures of obsessive–compulsive symptoms and beliefs, as well as posttraumatic cognitions. Results indicated that posttraumatic cognitions moderated the relationship between inflated responsibility and intolerance of uncertainty, which in turn predicted all domains of obsessive–compulsive symptom distress (all βs > 0.41, all zs > 3.44). Further, posttraumatic cognitions alone significantly predicting OC symptoms related to doubting, obsessions, and neutralizing. These findings suggest that shared cognitive constructs play a role in co-occurring posttraumatic stress and OC symptoms, and thus may be a relevant treatment target when these disorders present simultaneously.

Keywords

Obsessive–compulsive OCD Posttraumatic stress PTSD Intolerance of uncertainty Inflated responsibility Posttraumatic cognitions Moderator 

Introduction

The co-occurrence of obsessive–compulsive disorder (OCD) and posttraumatic stress disorder (PTSD) is common, with nearly one quarter of individuals with PTSD also experiencing OCD (Brown et al. 2001). Recent research has evaluated common and distinctive features of posttraumatic stress and obsessive–compulsive (OC) symptoms. This line of inquiry has even considered the possibility of a subtype of OCD directly induced by traumatic events (Fontanelle et al. 2012). Other investigations have instead suggested that many cases of OCD are an independent emotional result of childhood traumatic experiences (Lochner et al. 2002). Cognitive models have been proposed and tested to explain the distinct etiology and maintenance of PTSD (Foa et al. 2008) and OCD (Koran et al. 2010). As such, protocols for the treatment of PTSD as well as OCD emphasize challenging symptom-specific dysfunctional cognitions combined with exposure to feared situations and stimuli (i.e., Resick et al. 2008 for PTSD; McKay et al. 2015 for OCD).

Two constructs have been identified as closely associated with symptom severity in cognitive models of both PTSD and OCD: intolerance of uncertainty and inflated responsibility. Intolerance of uncertainty, heightened distress (often anxiety) under conditions in which outcomes are not pre-determined, has been shown to be associated with both posttraumatic stress (Bardeen et al. 2013) and OC symptoms (Gentes and Ruscio 2011). Inflated responsibility, the experience of bearing responsibility for events reasonably beyond one’s control, including the potential for feeling responsible for negative thoughts that might coincidentally occur during a negative outcome, has also been linked to both PTSD (Foa et al. 1999) and OCD (i.e., Wilhelm et al. 2010) symptom severity.

Despite the apparent commonalities between cognitive features driving PTSD and OCD symptoms, the research has been limited in explicitly evaluating cognitive constructs shared between the two conditions. Given that research has suggested that individuals with comorbid PTSD and OCD are less likely to respond to interventions known to be effective for each of these disorders separately (Gershuny et al. 2002, 2008), elucidating shared cognitive constructs as mechanisms for etiology and maintenance in PTSD and OCD could shed light on more effective methods for the treatment of individuals with co-occurring symptoms.

Thus, this study examined two cognitive constructs associated with posttraumatic and OC symptoms, intolerance of uncertainty and inflated responsibility, with posttraumatic cognitions as a moderator between these two constructs, in predicting OC symptoms among individuals who have experienced trauma. It was hypothesized that cognitions associated with PTSD would be significantly related to OC symptoms in trauma-exposed individuals, and that the interaction of posttraumatic cognitions, intolerance of uncertainty, and inflated responsibility would moderate distress associated with OC symptoms.

Methods

Participants

Participants (N = 211) were undergraduate students culled from the human participants research pool at Fordham University. Students were granted research credit in an introductory psychology course for participation in the study.

Measures

Trauma Exposure

Exposure to traumatic events among participants in the sample was assessed with the Life Events Checklist (LEC; Blake et al. 1995). The LEC is a self-report inventory of traumatic experiences. Respondents are presented with 17 different traumatic events and asked to indicate whether they have personally experienced, witnessed, or learned about each of these traumas, if they are not sure how to answer, or if the item does not apply to them. The LEC was originally developed as part of the Clinician Administered PTSD Scale procedures (CAPS; Blake et al. 1995), but also has satisfactory psychometric properties for independent administration. The LEC has shown acceptable test–retest reliability at a 1-week interval when dichotomized into personally experienced traumas versus witnessing or learning about these events (κ = 0.37–0.84, with most values between κ = 0.52–0.71; Gray et al. 2004). The LEC has demonstrated good convergent validity with other well validated measures of trauma exposure and psychological distress such as depression, anxiety, and PTSD symptoms (Gray et al. 2004).

Posttraumatic Cognitions

Posttraumatic cognitions (i.e., trauma related thoughts and beliefs) were measured with the Posttraumatic Cognitions Inventory (PTCI; Foa et al. 1999). The PTCI is a 36-item self-report questionnaire consisting of three subscales: Negative Cognitions About Self (e.g., “I am a weak person”), Negative Cognitions About the World (e.g., “The world is a dangerous place”), and Self-Blame (e.g., “The event happened because of the way I acted”). Respondents indicate the degree to which they agree with each statement on a seven-point Likert-type scale ranging from 1 (totally disagree) to 7 (totally agree). Higher scores represent more severe cognitions associated with trauma. The PTCI has demonstrated excellent internal consistency (Total: α = 0.97, Self: α = 0.97, World: α = 0.88, Blame: α = 0.86), as well as test–retest reliability at a 1-week interval (Total: ρ = 0.74, Self: ρ = 0.75, World: ρ = 0.89, Blame: ρ = 0.89; Foa et al. 1999). The PTCI has shown good convergent validity, correlating with other measures of PTSD symptoms, depression, and anxiety, and also has demonstrated good discriminant validity, distinguishing between individuals with and without PTSD in those who have experienced traumatic events (Foa et al. 1999).

Obsessive Beliefs

Obsessive beliefs (i.e., cognitive appraisals and styles associated with obsessionality, including perceptions of threat, responsibility, uncertainty, and importance/control of thoughts) were measured with the Obsessive Beliefs Questionnaire-44 [OBQ-44; Obsessive Compulsive Cognitions Working Group (OCCWG) 2005]. The OBQ-44 is a 44-item self-report questionnaire assessing cognitive patterns that contribute to obsessions. It consists of three subscales: Responsibility and Threat Estimation (e.g., “Even if harm is very unlikely, I should try to prevent it at any cost”), Perfectionism and Intolerance of Uncertainty (e.g., “If I’m not absolutely sure of something, I’m bound to make a mistake”), and Importance and Control of Thoughts (e.g., “For me, having bad urges is actually as bad as carrying them out”). Respondents rate agreement with each statement on a seven-point Likert-type scale ranging from 1 (disagree very much) to 7 (agree very much), with higher scores indicating more severe obsessive beliefs. The OBQ-44 has demonstrated excellent internal consistency (total: α = 0.95, responsibility/threat estimation: α = 0.93, perfectionism/certainty: α = 0.93, importance/control of thoughts: α = 0.89). It also has shown good convergent other well validated measures of OC symptoms, as well as discriminant validity with measures of depression and anxiety (OCCWG 2005).

Obsessive–Compulsive Disorder Symptoms

Symptoms of OCD were measured with the Obsessive–Compulsive Inventory (OCI; Foa et al. 1998). The OCI is a 42-item measure of OCD symptoms consisting of seven subscales: Washing, Checking, Doubting, Ordering, Obsessing (i.e., obsessional thoughts), Hoarding, and Mental Neutralizing. Respondents rate the frequency of symptoms and degree of associated distress in each symptom domain on a five-point Likert-type scale. Higher scores indicate more severe OC symptoms. The OCI has been shown to have high internal consistency (α = 0.68–0.96 for frequency and distress for all subscales) and test–retest reliability at a 2-week interval (r = .77–.97 for frequency and distress for all subscales; Foa et al. 1998). The OCI has demonstrated good convergent validity with other validated measures of OC symptoms, depression, and anxiety, and discriminates well between those with OCD and individuals with other anxiety disorders or no anxiety disorders on all distress and frequency subscales except Hoarding (Foa et al. 1998).

Procedures

This paper reports on secondary analyses of data collected as part of a larger investigation of anxiety, obsessive–compulsive, traumatic, and disgust reactions. The larger study was approved by the Institutional Review Board at Fordham University. Undergraduate students in introductory psychology classes at Fordham University accessed the study through the secure Sona Systems Ltd. Psychology Research Participation System. Participants gave electronic consent to participate in the study by reading a description of study purpose, procedures, risks, and benefits, and voluntarily proceeding to the start of the questionnaire battery on the following screen. This electronic informed consent form conveyed that participants were free to opt not to participate in the study and to exit study participation at any time without undue consequences. Participants who consented for study participation then completed a battery of self-report measures online via Survey Monkey’s web-based software.

Of the 245 individuals who completed this questionnaire battery, participants who reported experiencing or directly witnessing at least one traumatic event on the LEC (N = 211) were included in analyses examining relations between posttraumatic stress cognitions, obsessive–compulsive beliefs, and OC symptoms.

Analyses

Analyses were conducted using Stata 14 statistical software. We conducted moderator analyses (with means centered) whereby inflated responsibility, intolerance of uncertainty, and posttraumatic cognitions were expected to interact in predicting symptom severity for each subscale of the OCI among individuals with significant trauma histories. Due to the number of scales employed, we restricted the analyses to the interaction of these three variables, with posttraumatic cognitions moderating the relation between inflated responsibility and intolerance of uncertainty, in order to minimize for Type I error. With six OCI subscales, two predictors (i.e., inflated responsibility, intolerance of uncertainty), and a moderator term (i.e., PTSD cognitions), this resulted in 6 × 2 = 12 analyses. In order to adjust for Type I error, we used the False Discovery Rate (FDR; Benjamini and Hochberg 2000). Missing data were estimated using maximum likelihood procedures given the normal distribution of outcome variables.

Results

Participants were an average of 20.9 years old (SD = 5.7) and 67.8 % (n = 143) female. Further information on demographics and symptom severity of the sample are reported in Table 1.
Table 1

Characteristics of study sample

 

N (%)

Sex

 Male

68 (32.2)

 Female

143 (67.8)

Race

 American Indian or Alaska Native

1 (0.5)

 Asian

25 (11.8)

 Black/African American

11 (5.2)

 Caucasian

153 (72.5)

 Native Hawaiian or Pacific Islander

4 (1.9)

Ethnicity

 Hispanic

36 (17.1)

 Non-Hispanic

154 (73.0)

 

Mean (SD)

Age

20.89 (5.67)

LEC total traumas (experienced or witnessed)

5.25 (3.28)

 LEC number of traumas experienced

2.79 (2.34)

 LEC number of traumas witnessed

2.46 (2.22)

OBQ total

141.57 (38.03)

 OBQ responsibility

53.25 (16.13)

 OBQ uncertainty

59.69 (17.17)

 OBQ importance of thoughts

28.64 (10.84)

OCI total frequency

35.68 (24.43)

OCI total distress

22.46 (24.41)

PTCI total

88.63 (39.09)

SD standard deviation, LEC Life Events Checklist, OBQ Obsessive Beliefs Questionnaire-44, OCI Obsessive–Compulsive Inventory, PTCI Posttraumatic Cognitions Inventory

PTSD cognitions (as measured by PTCI total score) were significantly correlated with total OCD symptom frequency [r(210) = .47, p < .001] and distress [r(211) = .44, p < .001], as measured by the OCI. Moderator analysis using the FDR (adjusted critical p value .025, with original p values listed here) showed that inflated responsibility and intolerance of uncertainty, moderated by posttraumatic cognitions, predicted distress associated with all obsessive–compulsive symptom domains (see Table 2). Further, the main effect for posttraumatic cognitions was significantly predictive of OC symptoms of doubting, obsessions, and neutralizing (all z-scores > 2.54, p < .01 using FDR).
Table 2

Obsessive beliefs moderate relation between posttraumatic cognitions and obsessive–compulsive symptoms among trauma-exposed individuals (N = 211)

Cognitive domains

Obsessive compulsive symptoms (OCI-R)

Inflated responsibility (OBQ)

Intolerance of uncertainty (OBQ)

Posttraumatic cognitions (total PTCI)

Moderator term (posttraumatic cognitions moderating inflated responsibility and intolerance of uncertainty)

β

z

β

z

β

z

β

z

Washing

0.08

0.96

−0.12

−1.74

0.09

1.22

0.45

3.69**

Checking

0.06

0.87

−0.14

−1.99

0.17

2.44

0.52

4.34**

Doubting

0.01

0.08

−0.16

−2.50

0.24

3.79**

0.67

5.95**

Ordering

−0.09

−1.02

0.06

0.93

0.16

2.31

0.47

3.92**

Obsessions

0.17

1.96

0.14

−2.11

0.36

5.48**

0.41

3.44**

Neutralizing

−0.04

−0.56

0.11

1.97

0.17

2.54**

0.68

5.94**

OBQ Obsessive Compulsive Beliefs Questionnaire, PTCI Posttraumatic Cognitions Inventory

** p ≤ .001, and significant following correction with false discovery rate; all standard errors were between 0.003 and 0.007 for the main effects, and between 0.0001 and 0.0006 for the moderator term

Discussion

This study was conducted to evaluate the role of cognitions in a relatively common co-occurring clinical presentation of trauma associated with OCD (Fontanelle et al. 2012). The importance of elucidating factors associated with both PTSD and OCD is notable given research showing that many individuals with OCD report trauma, and that this specific clinical subsample is often treatment resistant (Gershuny et al. 2008). The current investigation found that the inflated responsibility and intolerance of uncertainty moderated by posttraumatic cognitions predicted distress related to several domains of OC symptom distress. This initial evidence suggests that intolerance of uncertainty and inflated responsibility may be shared cognitive mechanisms in maintaining clinical features of posttraumatic stress and obsessive–compulsive disorders, but with each effectively interacting with posttraumatic cognitions. Therefore, treatment focused on OC cognitions in trauma-exposure individuals should include consideration of posttraumatic cognitions such as concerns with self-blame, and negative thoughts about the self and world. These preliminary results may also suggest the possibility that features of OCD and/or PTSD emerge as a result of dysfunctional beliefs about conditions necessary for safety (e.g., certainty and control), including one’s personal role in ensuring safety of oneself and others. This hypothesis about the results of the current study is in line with the literature on co-occurring PTSD and OC symptoms, in which some authors have speculated that traumatic experiences, which by definition threaten one’s life and/or wellbeing, contribute to the development or intensification of safety-related cognitive processes (e.g., intolerance of uncertainty, inflated responsibility) in affected individuals (e.g., da Silva and Marks 2001; Gershuny et al. 2002). The findings from this line of research suggest that it may be necessary to assess posttraumatic cognitions in individuals reporting OC symptoms, particularly in the case of pure obsessions, excessive concerns with doubting, and neutralizing rituals. These practice standards would set the stage for more thorough treatment planning given the relevance of posttraumatic cognitions to OC symptoms.

It should be noted that this study restricted analyses to three cognitive domains that, based on prior research, have been shown to separately contribute to posttraumatic stress and OC symptoms. This is the first investigation to our knowledge to examine the interaction of these three cognitive domains in moderating OC symptoms. Future investigations evaluating a wider range of cognitive domains (such as overestimation of threat, for example) are warranted in light of the OCD literature, in which other cognitive domains have been shown to have at least as significant impact on etiology as those examined in the current study. For example, perfectionism and inflated concerns with control over thoughts have been found to significantly interact with inflated responsibility in predicting OC symptoms (Taylor et al. 2005). Other recent work also suggests that the need for control over thoughts uniquely predicts OC symptoms, and that the putative OC beliefs are not specific to OCD (McKay et al. 2014). Accordingly, further investigation is warranted examining the role of these additional cognitive domains in PTSD symptoms alone, as well as evaluating their potential moderating relationship between posttraumatic cognitions and OC symptoms as in the current study.

Given findings that individuals with OCD resulting from trauma have poor treatment outcome (Gershuny et al. 2002, 2008), and that many OCD sufferers report a past history of trauma (Brown et al. 2001), future work may also examine how these shared cognitive mechanisms may inform treatment of PTSD and OCD, occurring either together or separately. This could include evaluation of primary cognitions associated with trauma in samples presenting for treatment of OCD and would include negative views of the self, self-blame, and inflated sense of danger.

There were several limitations to this study that are important to consider. First, participants were undergraduate students at a private university and, while the sample endorsed significant trauma histories, the mean scores for all the symptom measures were below levels endorsed by clinically diagnosed samples.1 Although research supports the validity of analogue samples in understanding OC symptoms (Abramowitz et al. 2014) and suggests that both OC and posttraumatic stress symptoms exist along a continuum (e.g., Brown et al. 2001; Ruscio et al. 2002), it is important for future work to extend the present findings to individuals with clinically elevated PTSD symptoms in treatment-seeking and community populations. Future studies should also attempt to replicate these results using samples of a broader range of ages, as well as racial and ethnic diversity, in order to achieve greater generalizability of these findings and to increase the possibility of extending these preliminary findings to treatment implications.

This study was also limited by the fact that results are based solely on self-report of PTSD and OCD symptoms, as well as the relevant cognitive constructs. It is recommended that future studies utilize diagnostic interviews such as the CAPS to increase confidence in the validity of traumatic events and PTSD symptoms reported. However, precedent exists for screening undergraduate students for traumatic event exposure and posttraumatic stress symptoms utilizing a series of self-report questionnaires as in this study (e.g., Biehn et al. 2013; Elhai et al. 2009, 2012). In addition, further investigation by this group is currently underway to expand the current findings by utilizing experimental procedures to invoke intolerance of uncertainty and inflated responsibility. Finally, the limited sample size in this study was not sufficient for controlling for negative affect and gender in the moderation model. It is recommended that future work examine such variables, given that negative affect is present in both PTSD and OCD (e.g., Watson 2005), and that gender differences have been shown in OC symptom presentation and course and prevalence rates of PTSD (women higher; e.g., McLean and Anderson 2009).

Accordingly, this research is, to the authors’ knowledge, the first to examine intolerance of uncertainty, inflated responsibility, and posttraumatic cognitions as shared cognitive constructs in features of OCD and PTSD. Further research evaluating intolerance of uncertainty, inflated responsibility, and other cognitive constructs in cases of PTSD and OCD occurring both together and separately is warranted to further elucidate the relevance of these two cognitive domains in the etiology, maintenance, and treatment of both conditions.

Footnotes

  1. 1.

    Current sample: PTCI total median and SD = 81.00 (39.09) versus PTSD sample in Foa et al. (1999): PTCI total median and SD = 133 (44.17). Current sample: OCI Total Distress mean and SD = 22.46 (24.41) versus OCD sample in Foa et al. (1998): OCI total distress mean and SD = 66.33 (31.9). Current sample: OBQ-44 total mean and SD = 141.57 (38.03) versus OCD sample in OCCWG (2005): OBQ-44 total mean and SD = 174.3 (50.2).

Notes

Compliance with Ethical Standards

Conflict of Interest

Dean McKay, Rachel Ojserkis, and Jon D. Elhai declare that they have no conflicts of interest in the conduct of this work.

Informed Consent

We adhered to the ethical standards for treatment of human research participants as detailed in the Declaration of Helsinki. The Institutional Review Board of Fordham University approved this research, for the larger survey battery, in September 2011. Consent from participants was obtained between November 2011 and December 2013, during the period of data collection at Fordham University.

Animal Rights

No animals were used as part of this research.

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Copyright information

© Springer Science+Business Media New York 2015

Authors and Affiliations

  1. 1.Department of PsychologyFordham UniversityBronxUSA
  2. 2.University of ToledoToledoUSA

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