Thomas W. Freeman

Measuring symptom exaggeration in veterans with chronic posttraumatic stress disorder

Veteran subjects with chronic, combat-related posttraumatic stress disorder (PTSD) are frequently used as research subjects in the study of PTSD. However, questions have consistently been raised regarding PTSD symptom exaggeration in veteran populations due to the relationship between PTSD symptoms and disability payments within the Veterans Affairs (VA) system. We used a variety of standardized forensic instruments frequently utilized in measuring symptom exaggeration - including the MMPI-2, the Structured Interview for Reported Symptoms (SIRS), the Structured Inventory of Malingered Symptomatology (SIMS), and the Miller Forensic Assessment Test (MFAST) - to examine symptom report in a group of veterans presenting for treatment at a VA residential PTSD treatment program. The majority of Vietnam veteran subjects in our study (53%) exhibited clear symptom exaggeration by SIRS criteria. Within the entire subject group, total SIRS scores correlated significantly with reported PTSD symptom severity as measured by the Clinician Administered PTSD Scale (CAPS).

Combat veterans with posttraumatic stress disorder exhibit decreased habituation of the P1 midlatency auditory evoked potential

The current study used a paired stimulus paradigm to investigate the P1 midlatency auditory evoked potential in Vietnam combat veterans with posttraumatic stress disorder (PTSD) and three comparison groups: alcohol dependents, combat-exposed normals, and combat-unexposed normals. Compared to each comparison group, PTSD subjects exhibited significantly diminished habituation of the P1 potential. P1 potential habituation within the PTSD group, correlated significantly with intensity of PTSD reexperiencing symptoms, such as trauma-related nightmares and flashbacks. These findings are discussed as consistent with a sensory gating defect at the brainstem level in PTSD, and are further discussed in the context of other psychophysiological measures in PTSD and of P1 potential findings in psychiatric disorders other than PTSD.

Gun use, attitudes toward violence, and aggression among combat veterans with chronic posttraumatic stress disorder.

Vietnam veterans with chronic combat-related posttraumatic stress disorder (PTSD) have been frequently reported to exhibit high levels of aggression and violent behavior. In this study, gun collection and use habits, attitudes toward violence, and self-reported levels of aggression were compared between veterans with chronic PTSD and non-PTSD veterans with equivalent histories of alcohol and substance abuse. PTSD patients reported different attitudes toward violent crime, higher levels of self-reported aggression, and a significantly higher incidence of potentially dangerous firearm-related behaviors than comparison subjects.

Evidence of resilience: Neuroimaging in former prisoners of war

In this study, single voxel proton magnetic resonance spectroscopic imaging ((1)H-MRS) and volumetric analysis of hippocampal magnetic resonance imaging (MRI) images were used to determine if any differences in hippocampal biochemistry or volume were present between former prisoners of war (POWs) with and without posttraumatic stress disorder (PTSD) and control subjects matched for age and education. This study did not find lower hippocampal concentrations of N-acetylaspartate (NAA), smaller hippocampal volumes, or more impaired memory function in older veterans with PTSD compared with a group matched for traumatic experience or a nontraumatized control group.

A survey of gun collection and use among three groups of veteran patients admitted to veterans affairs hospital treatment programs.

Background An important risk factor for suicide is psychiatric illness, but only a limited amount of work has been directed at assessing the use of firearms and other weapons by select psychiatric populations at high risk for violent acts. Method Patients with combat-related posttraumatic stress disorder (PTSD), patients with schizophrenia, and patients undergoing rehabilitation for substance abuse were asked to complete a weapons-use survey and measures of psychopathology. Results The PTSD patients surveyed related owning more than four times as many firearms as other subjects and reported significantly higher levels of potentially dangerous firearm-related behaviors than the other psychiatric subjects surveyed. Conclusion High levels of aggression, impulsive and dangerous weapon use, and ready weapon availability may be significant factors in gun-related violence in the PTSD patient population. Additional prospective research is needed to determine whether gun ownership or certain types of weapon use in this population is associated with future acts of violence.

Cognitive Dysfunctions Associated With PTSD : Evidence from World War II Prisoners of War

The authors aim to delineate cognitive dysfunction associated with posttraumatic stress disorder (PTSD) by evaluating a well-defined cohort of former World War II prisoners of war (POWs) with documented trauma and minimal comorbidities. The authors studied a cross-sectional assessment of neuropsychological performance in former POWs with PTSD, PTSD with other psychiatric comorbidities, and those with no PTSD or psychiatric diagnoses. Participants who developed PTSD had average IQ, while those who did not develop PTSD after similar traumatic experiences had higher IQs than average (approximately 116). Those with PTSD performed significantly less well in tests of selective frontal lobe functions and psychomotor speed. In addition, PTSD patients with co-occurring psychiatric conditions experienced impairment in recognition memory for faces. Higher IQ appears to protect individuals who undergo a traumatic experience from developing long-term PTSD, while cognitive dysfunctions appear to develop with or subsequent to PTSD. These distinctions were supported by the negative and positive correlations of these cognitive dysfunctions with quantitative markers of trauma, respectively. There is a suggestion that some cognitive decrements occur in PTSD patients only when they have comorbid psychiatric diagnoses.

Neuroanatomic Organization of Sound Memory in Humans

The neural interface between sensory perception and memory is a central issue in neuroscience, particularly initial memory organization following perceptual analyses. We used functional magnetic resonance imaging to identify anatomic regions extracting initial auditory semantic memory information related to environmental sounds. Two distinct anatomic foci were detected in the right superior temporal gyrus when subjects identified sounds representing either animals or threatening items. Threatening animal stimuli elicited signal changes in both foci, suggesting a distributed neural representation. Our results demonstrate both category- and feature-specific responses to nonverbal sounds in early stages of extracting semantic memory information from these sounds. This organization allows for these category-feature detection nodes to extract early, semantic memory information for efficient processing of transient sound stimuli. Neural regions selective for threatening sounds are similar to those of nonhuman primates, demonstrating semantic memory organization for basic biological/survival primitives are present across species.

Comprehension of affective prosody in veterans with chronic posttraumatic stress disorder

Posttraumatic stress disorder (PTSD) is one of the few psychiatric conditions in which a subjective decrease in emotional range serves as a diagnostic criterion. In order to investigate whether veterans with chronic PTSD also experienced objective limitations in emotional perception, the authors administered the Aprosodia Battery to a group of 11 veterans with chronic PTSD, nine subjects with right hemisphere damage, seven subjects with left hemisphere damage, and 12 comparison subjects. The patients with PTSD displayed significant deficiencies in the comprehension and discriminative components of affective speech, similar in severity and performance profile on the Aprosodia Battery to the individuals with focal right hemisphere damage due to ischemic infarction.

Repetitive Transcranial Magnetic Stimulation and Threat Memory: Selective Reduction of Combat Threat Memory P300 Response After Right Frontal-Lobe Stimulation

Using the event-related potential P3a component as a marker, the authors tested the efficacy of repetitive transcranial magnetic stimulation (rTMS) for reducing hyperarousability to specific threat stimuli in one Vietnam veteran with chronic posttraumatic stress disorder (PTSD), who exhibited an exaggerated P3a response to combat-related pictures. Twenty minutes of 1-Hz rTMS to the right prefrontal area effected a reduction in the P3a amplitude, whereas similar rTMS to the left prefrontal area did not. In addition to providing evidence for the effectiveness of right frontal rTMS for an exaggerated response to trauma-related stimuli, this study provides electrophysiological corroboration of subjective reports of PTSD symptoms.

Weight loss and PTSD symptom severity in former POWs

To determine the relationship between weight loss suffered by former prisoners of war during captivity during World War II and the Korean Conflict and current posttraumatic stress disorder (PTSD) symptoms, the Clinician-Administered PTSD Symptom Scale, a lifetime stressor checklist, and the Structured Clinical Interview for DSM-IV were administered to 102 former prisoners of war. Preconfinement and postconfinement weights and length of confinement were obtained from military medical records. Percentage of body weight lost during captivity was significantly higher in those subjects with PTSD and correlated with current PTSD symptom severity. Length of confinement was not associated with current PTSD symptoms.