Prospective Memory in Posttraumatic Stress Disorder

Poorer prospective memory performance is associated with reduced time monitoring among OEF/OIF/OND Veterans with a history of blast-related mild traumatic brain injury

Objective:Prospective memory (PM) or "remembering to remember" has been shown to be reduced in Veterans with histories of mild traumatic brain injury (mTBI), particularly on tasks with high strategic demands such as recalling time-based information in the absence of external cues. This study examined whether time monitoring during a PM task was reduced in Veterans with a history of mTBI and was associated with time-based PM performance. Method:Veterans with a history of mTBI (n = 49) and Veterans without a history of TBI (n = 16) completed the Memory for Intentions Screening Test (MIST) as a measure of PM during which their time monitoring (i.e. number of clock checks) was recorded. Results:Adjusting for age, education, depression, and PTSD symptoms, negative binomial regression revealed that the mTBI group checked the clock less frequently compared to the control group (Cohen's d = 0.84, p = 0.005). Within the mTBI group, less frequent time monitoring across the entire MIST task was associated with poorer time-based MIST performance (r_s = .57, p < 0.001), but not with event-based MIST (r_s = .04, p = 0.768). Conclusions:Veterans with a history of mTBI evidenced significantly reduced time monitoring during a PM task compared to Veterans without a history mTBI, which was associated with strategically-demanding PM. Current findings provide that mTBI-associated difficulties with strategic aspects of PM may be due to reduced time monitoring. Future studies are needed to determine if reduced time monitoring also contributes to mTBI-associated PM difficulties in the real-world (e.g. medication non-adherence).

I forgot that I forgot: PTSD symptom severity in a general population correlates with everyday diary-recorded prospective memory failures

Extant research suggests a complex relationship between prospective memory (PM) and post-traumatic stress disorder (PTSD) symptom severity. In a general population, this relationship exists for self-report assessment but not objective, in-lab PM performance (e.g., pressing a certain key at a particular time, or when particular words appear). However, both these measurement methods have limitations. Objective, in-lab PM tasks might not represent typical everyday performance, while self-report measurement might be biased by metacognitive beliefs. Thus, we used a naturalistic diary paradigm to answer the overarching question: are PTSD symptoms associated with PM failures in everyday life? We found a small positive correlation between diary-recorded PM errors and PTSD symptom severity (r = .21). Time-based tasks (i.e., intentions completed at a particular time, or after a specified time has elapsed; r = .29), but not event-based tasks (i.e., intentions completed in response to an environmental cue; r = .08), correlated with PTSD symptoms. Moreover, although diary-recorded and self-report PM correlated, we did not replicate the finding that metacognitive beliefs underpin the PM-PTSD relationship. These results suggest that metacognitive beliefs might be particularly important for self-report PM only.

Associations between Intra-Individual Neurocognitive Variability and Prospective Memory in Veterans with Mild Traumatic Brain Injury History and Posttraumatic Stress Disorder

OBJECTIVE

Mild traumatic brain injury (mTBI) and posttraumatic stress disorder (PTSD) frequently co-occur and are associated with neurocognitive intra-individual variability (IIV) and difficulty with prospective memory (PM). The current study aimed to examine associations between IIV and PM in this comorbid group.

METHOD

Fifty veterans with a history of blast mTBI and current comorbid PTSD completed a standardized neurocognitive battery to measure IIV, and the Memory for Intentions Screening Test measuring PM.

RESULTS

Adjusting for age, education, and race, higher IIV was associated with poorer time-based PM (p < .001, f2 = .34), but not event-based PM. In a subset of the sample with self-report data, higher IIV was associated with poorer self-reported retrospective memory, but not PM.

CONCLUSIONS

Cognitive variability on a standardized neuropsychological battery was associated with strategically demanding PM, which is an ecologically relevant ability and highlights the possible connection between subtle cognitive difficulties in-clinic and those experienced in daily life.

Psychometrics and Validity of the Survey of Memory-Related Quality of Life in HIV Disease

OBJECTIVE

Retrospective and prospective memory deficits are associated with lower quality of life (QoL); however, there are no validated measures that comprehensively and directly assess the impact of memory problems on QoL. The Survey of Memory-Related Quality of Life (SMRQoL) was developed as a 30-item questionnaire to measure memory-related QoL.

METHOD

Both HIV+ (n = 195) and HIV- (n = 146) participants completed the SMRQoL, a neurocognitive research battery, and validated self-report questionnaires of memory, QoL, and mood. Participants were recruited into younger (age ≤ 40 years) and older (age ≥ 50 years) groups per the parent study design.

RESULTS

The SMRQoL had a unidimensional factor structure and demonstrated measurement invariance across the HIV+ and HIV- participants. Analyses of 111 clinically stable participants (e.g., persons with no incident or remitting central nervous system disorders) who returned for a 14-month follow-up visit indicated that the SMRQoL had adequate test-retest stability. There was a significant interaction of age and HIV status on the SMRQoL, such that older HIV+ participants reported the lowest memory-related QoL. SMRQoL scores were associated with validated measures of mental and physical QoL, self-reported memory and cognitive symptoms, and performance-based memory and executive functions.

CONCLUSIONS

The SMRQoL shows evidence of reliability and validity as a measure of memory-related QoL that can be used to assess the impact of memory problems on everyday life, but future work is needed to demonstrate the measure's incremental value in the context of diagnosis and treatment.

Neurocognitive Predictors of Treatment Outcomes in Cognitive Processing Therapy for Post-traumatic Stress Disorder: Study Protocol

Background

Post-traumatic stress disorder (PTSD) is a prevalent, debilitating, and costly psychiatric disorder. Evidenced-based psychotherapies, including Cognitive Processing Therapy (CPT), are effective in treating PTSD, although a fair proportion of individuals show limited benefit from such treatments. CPT requires cognitive demands such as encoding, recalling, and implementing new information, resulting in behavioral change that may improve PTSD symptoms. Individuals with PTSD show worse cognitive functioning than those without PTSD, particularly in acquisition of verbal memory. Therefore, memory dysfunction may limit treatment gains in CPT in some individuals with PTSD.

Methods and Analysis

Here, we present a protocol describing the Cognition and PsychoTherapy in PTSD (CPTPTSD) study, a prospective, observational study examining how cognitive functioning affects treatment response in CPT for PTSD (NCT# 03641924). The study aims to recruit 105 outpatient veterans with PTSD between the ages of 18 and 70 years. Prior to beginning 12 sessions of CPT, Veteran participants will have standardized assessments of mood and functioning and complete a comprehensive neurocognitive battery assessing episodic learning, attention and speed of processing, language ability, executive control, and emotional functioning. This study aims to fill gaps in the current literature by: (1) examining the specificity of memory effects on treatment response; (2) exploring how baseline cognitive functioning impacts functional outcomes; and (3) examining potential mechanisms, such as memory for treatment content, that might explain the effects of baseline memory functioning on PTSD symptom trajectory.

Discussion

If successful, this research could identify clinically relevant neurocognitive mechanisms that may impact PTSD psychotherapy and guide the development of individualized treatments for PTSD.

Preliminary evidence for a relationship between prospective memory and PTSD symptoms in the general population

INTRODUCTION

PTSD sufferers often have problems with remembering the past, but do they also have trouble remembering tasks to be completed in the future? We argue characteristics of PTSD-such as negative appraisals and maladaptive strategies-might contribute to biased reporting of prospective memory failures among PTSD sufferers-or people with severe PTSD symptoms-within a general population.

METHODS

Mechanical Turk participants completed a questionnaire battery measuring self-report prospective memory, PTSD symptoms, negative appraisals and maladaptive strategies (e.g., suppression), and depression, anxiety and stress symptoms.

RESULTS

PTSD symptom severity positively correlated with self-report prospective memory failures (rs = .42-49). PTSD symptoms affected self-report prospective memory via their influence on negative appraisals and maladaptive strategies.

LIMITATIONS

Our findings rely on self-report, therefore we do not know if this relationship generalizes to objective prospective memory tasks.

CONCLUSIONS

Our data provide preliminary evidence for a relationship between PTSD symptomatology and subjective prospective memory in the general population and suggest that the negative appraisals and maladaptive strategies that commonly accompany PTSD might underpin this relationship.

Deficits in episodic memory and mental time travel in patients with post-traumatic stress disorder

Post-traumatic stress disorder (PTSD) is characterized by impairments in mnestic functions, especially in the domain of episodic memory. These alterations might affect different aspects of episodic memory functioning. Here we tested PTSD patients and healthy controls (matched for age, sex and education) in a newly developed virtual reality episodic memory test (VR-EMT), a test for mental time travel, episodic future thinking, and prospective memory (M3xT). In a cross-validation experiment, their performance was further evaluated in the Rivermead Behavioral Memory Test (RBMT). PTSD patients demonstrated impairments in episodic memory formation and mental time travel and showed difficulties in utilizing information from episodic memory to solve problems. Diminished attention and concentration in PTSD did not account for performance deficits in these tasks but higher levels of negative arousal were found in PTSD patients. Furthermore, performance in the VR-EMT and RBMT in PTSD patients correlated negatively with self-reported measures of stress and depression. Our results suggest that deficits in episodic memory formation and mental time travel in PTSD lead to difficulties in utilizing the content of episodic memories for solving problems in the present or to plan future behavior. Clinical implications of these findings and suggestions for cognitive-behavioral treatment of PTSD are discussed.

Retrospective and Prospective Memory Among OEF/OIF/OND Veterans With a Self-Reported History of Blast-Related mTBI

OBJECTIVES

To evaluate prospective and retrospective memory abilities in Operation Enduring Freedom (OEF), Operation Iraqi Freedom (OIF), and Operation New Dawn (OND) Veterans with and without a self-reported history of blast-related mild traumatic brain injury (mTBI).

METHODS

Sixty-one OEF/OIF/OND Veterans, including Veterans with a self-reported history of blast-related mTBI (mTBI group; n=42) and Veterans without a self-reported history of TBI (control group; n=19) completed the Memory for Intentions Test, a measure of prospective memory (PM), and two measures of retrospective memory (RM), the California Verbal Learning Test-II and the Brief Visuospatial Memory Test-Revised.

RESULTS

Veterans in the mTBI group exhibited significantly lower PM performance than the control group, but the groups did not differ in their performance on RM measures. Further analysis revealed that Veterans in the mTBI group with current PTSD (mTBI/PTSD+) demonstrated significantly lower performance on the PM measure than Veterans in the control group. PM performance by Veterans in the mTBI group without current PTSD (mTBI/PTSD-) was intermediate between the mTBI/PTSD+ and control groups, and results for the mTBI/PTSD- group were not significantly different from either of the other two groups.

CONCLUSIONS

Results suggest that PM performance may be a sensitive marker of cognitive dysfunction among OEF/OIF/OND Veterans with a history of self-reported blast-related mTBI and comorbid PTSD. Reduced PM may account, in part, for complaints of cognitive difficulties in this Veteran cohort, even years post-injury. (JINS, 2018, 24, 324-334).

Cortical thickness reduction in combat exposed U.S. veterans with and without PTSD

We investigated the extent of cortical thinning in U.S. Veterans exposed to combat who varied in the severity of their posttraumatic stress disorder (PTSD) symptoms. In addition, we explored the neural correlates of PTSD symptom dimensions and the interactive effects of combat exposure and PTSD upon cortical thickness. Sixty-nine combat exposed Veterans completed high-resolution magnetic resonance imaging (MRI) scans to estimate cortical thickness. The Clinician Administered PTSD Scale (CAPS) and Combat Exposure Scale (CES) assessments were completed to measure current PTSD and historical combat severity, respectively. PTSD symptom dimensions (numbing, avoidance, reexperiencing, anxious arousal, and dysphoric arousal) were studied. Vertex-wise whole cerebrum analyses were conducted. We found widespread negative correlations between CAPS severity and cortical thickness, particularly within the prefrontal cortex. This prefrontal correlation remained significant after controlling for depression severity, medication status, and other potential confounds. PTSD dimensions, except anxious arousal, negatively correlated with cortical thickness in various unique brain regions. CES negatively correlated with cortical thickness in the left lateral prefrontal, regardless of PTSD diagnosis. A significant interaction between CES and PTSD diagnosis was found, such that CES negatively correlated with cortical thickness in the non-PTSD, but not in the PTSD, participants. The results underscore the severity of cortical thinning in U.S. Veterans suffering from high level of PTSD symptoms, as well as in Veterans with no PTSD diagnosis but severe combat exposure. The latter finding raises considerable concerns about a concealed injury potentially related to combat exposure in the post-9/11 era.