Differentiating between appraisal process and product in cognitive theories of posttraumatic stress

Cognitive biases in military personnel with and without PTSD: a systematic review

BACKGROUND

Some cognitive biases, such as excessive attention to threat, are associated with PTSD. However, they may be adaptive for military personnel; attending to threat may improve safety for deployed personnel.

AIMS

The extent to which military personnel with vs. without PTSD differ with respect to specific cognitive biases is currently unclear. This systematic review aimed to address this question.

METHODS

PRISMA guidelines were followed. Articles were identified using a comprehensive literature search; 21 studies (with 1977 participants) were reviewed.

RESULTS

All studies were of "moderate" or "strong" quality. Military personnel with vs. without PTSD used overgeneralised language when describing autobiographical memories and demonstrated impaired performance on a modified Stroop task. Studies using dot-probe paradigms conceptualised attentional response as a dynamic process, fluctuating between bias towards and away from threat; military personnel with vs. without PTSD demonstrated greater fluctuation. Studies using visual search tasks concluded that attentional bias in PTSD involves interference (difficulty disengaging from threat) rather than facilitation (enhanced threat detection). Finally, personnel with vs. without PTSD demonstrated interpretation bias, completing ambiguous sentences with negative rather than neutral endings.

CONCLUSION

The implications for military populations and recommendations for further research and clinical practice are considered.

PROSPERO REGISTRATION

PROSPERO 2018 CRD42018092235.

Illness-related intrusive thoughts and illness anxiety disorder

INTRODUCTION

Intrusive thoughts about health threats (illness-ITs) are a potential cognitive risk factor for the development and maintenance of illness anxiety disorder (IAD). This study analyzes the dimensionality of illness-ITs from normalcy to psychopathology, and it evaluates whether the appraisals instigated by the Its mediate between these thoughts and IAD symptoms.

METHODS

Two groups of individuals participated in the study and completed the Illness Intrusive Thoughts Inventory and the Whiteley Index. The first group was composed of 446 non-clinical community participants. Of them, 264 individuals (68.6% women; M_age  = 30.03 [SD = 13.83]) reported having experienced an upsetting illness-IT in the past three months and were then included in the main analyses. The second group included 31 patients with a current main diagnosis of IAD based on DSM-5 criteria (51.6% women; M_age  = 32.74 [SD = 9.69]). Their severity was assessed with the Hypochondriasis Yale-Brown Obsessive-Compulsive Scale -Modified version, with scores ranging from 15 to 58 (M = 46.12, SD = 9.41).

RESULTS

Illness-ITs are common in both non-clinical individuals and in patients with IAD, and they instigate dysfunctional emotional, cognitive, and behavioral consequences, although with greater intensity in patients than in non-clinical individuals. The relationship between illness-ITs and IAD is mediated by overestimation of threat and thought-action fusion-probability appraisals.

CONCLUSION

Illness-ITs are a dimensional cognitive experience. The way they are appraised facilitates their escalation into symptoms of IAD.

PRACTITIONER POINTS

Provides support for the cognitive explanatory model of IAD and its usefulness in clinical practice. Indicates that the way people interpret and react to naturally occurring intrusive thoughts about illness seems to be a vulnerability marker for developing an illness anxiety disorder. Emphasizes that the meaning that patients with IAD ascribe to their intrusive thoughts about illnesses must be a main target in the cognitive-behavioral treatment of IAD. Suggests that the importance of intrusive thoughts in IAD does not lie in the frequency with which they are experienced, but in the way, they are appraised/interpreted, which is what determines whether they become a clinically significant symptom. Indicates that the relationship between illness intrusive thoughts and IAD symptoms in non-clinical individuals is based on: overestimating the negative consequences of experiencing an illness intrusive thought; and the appraisal that having such a thought would increase its likelihood of coming true. Shows that the frequency of illness-related intrusive cognitions is associated with worse cognitive and behavioral consequences.

Heart Rate Variability and Cognitive Bias Feedback Interventions to Prevent Post-deployment PTSD: Results from a Randomized Controlled Trial

Introduction

There is a long history of pre-deployment PTSD prevention efforts in the military and effective pre-deployment strategies to prevent post-deployment PTSD are still needed.

Materials and Methods

This randomized controlled trial included three arms: heart rate variability biofeedback (HRVB), cognitive bias modification for interpretation (CBM-I), and control. The hypothesis was that pre-deployment resilience training would result in lower post-deployment PTSD symptoms compared with control. Army National Guard soldiers (n = 342) were enrolled in the Warriors Achieving Resilience (WAR) study and analyzed. The outcome was PTSD symptom severity using the PTSD Checklist - Military version (PCL) measured at pre-deployment, 3- and 12-month post-deployment. Due to the repeated measures for each participant and cluster randomization at the company level, generalized linear mixed models were used for the analysis. This study was approved by the Army Human Research Protection Office, Central Arkansas Veterans Healthcare System Institutional Review Board (IRB), and Southeast Louisiana Veterans Health Care System IRB.

Results

Overall, there was no significant intervention effect. However, there were significant intervention effects for subgroups of soldiers. For example, at 3-months post-deployment, the HRVB arm had significantly lower PCL scores than the control arm for soldiers with no previous combat zone exposure who were age 30 and older and for soldiers with previous combat zone exposure who were 45 and older (unadjusted effect size -0.97 and -1.03, respectively). A significant difference between the CBM-I and control arms was found for soldiers without previous combat zone exposure between ages 23 and 42 (unadjusted effect size -0.41). Similarly, at 12-months post-deployment, the HRVB arm had significantly lower PCL scores in older soldiers.

Conclusion

Pre-deployment resilience training was acceptable and feasible and resulted in lower post-deployment PTSD symptom scores in subgroups of older soldiers compared with controls. Strengths of the study included cluster randomization at the company level, use of iPod device to deliver the resilience intervention throughout the deployment cycle, and minimal disruption of pre-deployment training by using self-paced resilience training. Weaknesses included self-report app use, study personnel not able to contact soldiers during deployment, and in general a low level of PTSD symptom severity throughout the study. In future studies, it would important for the study team and/or military personnel implementing the resilience training to be in frequent contact with participants to ensure proper use of the resilience training apps.

Development of the Interpretation Bias Index for PTSD

Cognitive models of posttraumatic stress disorder (PTSD) implicate interpretation biases as a maintaining factor of symptoms. Existing measures index symptoms and negative beliefs in PTSD patients, but not threatening interpretation of socially-ambiguous information, which would further inform cognitive models of PTSD. Here we describe the development of a measure of interpretation bias specific to individuals with PTSD. Studies 1 and 2 utilized analog samples to identify the smallest set of items capable of differentiating PTSD-specific interpretation biases. Study 3 utilized a clinical sample to examine the factor structure of the 9-item Interpretation Bias Index for PTSD (IBIP). A bifactor model fit the IBIP best, comprising a general PTSD factor and two subfactors. The IBIP was most strongly related to PTSD symptoms and demonstrated sensitivity and specificity to detecting true PTSD cases. The IBIP has potential clinical utility for tracking interpretation bias in PTSD, or even screening for PTSD diagnoses.