A positron emission tomographic study of symptom provocation in PTSD

Effects of transcranial direct current stimulation (tDCS) in "Kiss nightclub fire" patients with post-traumatic stress disorder (PTSD): A phase II clinical trial

Objective

Considered the second biggest tragedy with fatal victims caused by fire, the Kiss nightclub fire tragedy that occurred in the interior of southern Brazil brought several problems to survivors. It is reported that 30-40% of victims of disasters can develop post-traumatic stress disorder. Application of repetitive transcranial magnetic stimulation has shown promising results in the treatment of post-traumatic stress disorder. Transcranial direct current stimulation similar to repetitive transcranial magnetic stimulation, a neuromodulation technique, has shown promise in treatment of neuropsychiatric disorders.

Method

A clinical trial was conducted from March 2015 to July 2016 in "KISS nightclub fire" disaster patients diagnosed with post-traumatic stress disorder without complete remission of symptoms, over 18 years, and who maintained pharmacological treatment. Treatment was given using electrodes as cathode (right dorsolateral prefrontal cortex) and anode (contralateral deltoid muscle); a current of 2 mA was used for 25 cm² area (0.08 mA/cm² current density); 30 min once a day for 10 days continuously. Patients assessed pre- and post-intervention, 30 days' and 90 days' post-intervention. Post-Traumatic Stress Disorder Checklist, Civilian version, Montreal Cognitive Assessment, and Hamilton Depression and Anxiety Rating Scale were used.

Results

One hundred forty-five subjects were screened and eight analyzed; 87.5% were female; 30.88 ± 7.74 years were of mean age. Post-intervention results: no cognitive impairment (Montreal Cognitive Assessment), 60% reduction in Hamilton Depression Rating Scale (moderate depression turns normal) (p < 0.001), 54.39% Hamilton Anxiety Rating Scale reduction (moderate-to-severe symptoms turn into mild symptoms) (p < 0.001), and 20% Post-Traumatic Stress Disorder Checklist, Civilian version scale decrease (high severity post-traumatic stress disorder symptoms turn moderate to moderately high severity) (p < 0.001). Post-traumatic stress disorder symptoms improvement was maintained 30-days post-intervention (Post-Traumatic Stress Disorder Checklist, Civilian version, p = 0.025) and improvement in symptoms of depression (Hamilton Depression Rating Scale, p = 0.006) and anxiety (Hamilton Anxiety Rating Scale, p = 0.028) in 90 days post-intervention.

Conclusion

Despite decrease over time, improvement in post-traumatic stress disorder, depression and anxiety symptoms was maintained throughout the first month after treatment. Transcranial direct current stimulation adjuvant can be an alternative treatment to refractory post-traumatic stress disorder, either as monotherapy or as treatment enhancement strategy. They can also be an option for patients who do not want or do not tolerate pharmacological management.

The advent of fear conditioning as an animal model of post-traumatic stress disorder: Learning from the past to shape the future of PTSD research

Translational research on post-traumatic stress disorder (PTSD) has produced limited improvements in clinical practice. Fear conditioning (FC) is one of the dominant animal models of PTSD. In fact, FC is used in many different ways to model PTSD. The variety of FC-based models is ill defined, creating confusion and conceptual vagueness, which in turn impedes translation into the clinic. This article takes a historical and conceptual approach to provide a comprehensive picture of current research and help reorient the research focus. This work historically reviews the variety of models that have emerged from the initial association of PTSD with FC, highlighting conceptual pitfalls that have limited the translation of animal research into clinical advances. We then provide some guidance on how future translational research could benefit from conceptual and technological improvements to translate basic findings in patients. This objective will require transdisciplinary approaches and should involve physicians, engineers, philosophers, and neuroscientists.

'Master My Demons': art therapy montage paintings by active-duty military service members with traumatic brain injury and post-traumatic stress

This study involved a thematic analysis of montage paintings and of related clinical records of 240 active-duty military service members collected during their art therapy treatment for traumatic brain injury and underlying psychological health concerns, including post-traumatic stress, at the National Intrepid Center of Excellence, Walter Reed National Military Medical Center, Bethesda, Maryland, USA. Congruent with other research findings, the qualitative analyses of this study suggest that the group art therapy experiences fostered improvement in interpersonal relatedness, hopefulness and gratification for the service members in treatment, aiding in externalisation, progressive exposure and construction of a trauma narrative imperative for recovery. The mixed media nature of the montage painting supported the expression of a range of postcombat symptoms. Results from this study highlighted the complexity of military culture, necessitating a broader scope of analyses for how art therapy helps service members express and communicate their challenges to care providers, peers and family as well as regulate emotion in the short and long term.

A Review of fMRI Affective Processing Paradigms Used in the Neurobiological Study of Posttraumatic Stress Disorder

Posttraumatic stress disorder (PTSD) is a chronic and debilitating psychiatric disorder with a complex clinical presentation. The last two decades have seen a proliferation of literature on the neurobiological mechanisms subserving affective processing in PTSD. The current review will summarize the neuroimaging results of the most common experimental designs used to elucidate the affective signature of PTSD. From this summary, we will provide a heuristic to organize the various paradigms discussed and report neural patterns of activations using this heuristic as a framework. Next, we will compare these results to the traditional functional neurocircuitry model of PTSD and discuss biological and analytic variables which may account for the heterogeneity within this literature. We hope that this approach may elucidate the role of experimental parameters in influencing neuroimaging findings.

Observational study of associations between visual imagery and measures of depression, anxiety and post-traumatic stress among active-duty military service members with traumatic brain injury at the Walter Reed National Military Medical Center

OBJECTIVES

The study aimed tocompare recurring themes in the artistic expression of military service members (SMs) with post-traumatic stress disorder (PTSD), traumatic brain injury and psychological health (PH) conditions with measurable psychiatric diagnoses. Affective symptoms and struggles related to verbally expressing information can limit communication in individuals with symptoms of PTSD and deployment-related health conditions. Visual self-expression through art therapy is an alternative way for SMs with PTSD and other PH conditions to communicate their lived experiences. This study offers the first systematic examination of the associations between visual self-expression and standardised clinical self-report measures.

DESIGN

Observational study of correlations between clinical symptoms of post-traumatic stress, depression and anxiety and visual themes in mask imagery.

SETTING

The National Intrepid Center of Excellence at the Walter Reed National Military Medical Center, Bethesda, Maryland, USA.

PARTICIPANTS

Active-duty military SMs (n=370) with a history of traumatic brain injury, post-traumatic stress symptoms and related PH conditions.

INTERVENTION

The masks used for analysis were created by the SMs during art therapy sessions in week 1 of a 4-week integrative treatment programme.

PRIMARY OUTCOMES

Associations between scores on the PTSD Checklist-Military, Patient Health Questionnaire-9 and Generalized Anxiety Disorder 7-item scale on visual themes in depictions of aspects of individual identity (psychological injury, military symbols, military identity and visual metaphors).

RESULTS

Visual and clinical data comparisons indicate that SMs who depicted psychological injury had higher scores for post-traumatic stress and depression. The depiction of military unit identity, nature metaphors, sociocultural metaphors, and cultural and historical characters was associated with lower post-traumatic stress, depression and anxiety scores. Colour-related symbolism and fragmented military symbols were associated with higher anxiety, depression and post-traumatic stress scores.

CONCLUSIONS

Emergent patterns of resilience and risk embedded in the use of images created by the participants could provide valuable information for patients, clinicians and caregivers.

Neural responses to emotional involuntary memories in posttraumatic stress disorder: Differences in timing and activity

Background

Involuntary memories are a hallmark symptom of posttraumatic stress disorder (PTSD), but studies of the neural basis of involuntary memory retrieval in posttraumatic stress disorder (PTSD) are sparse. The study of the neural correlates of involuntary memories of stressful events in PTSD focuses on the voluntary retrieval of memories that are sometimes recalled as intrusive involuntary memories, not on involuntary retrieval while being scanned. Involuntary memory retrieval in controls has been shown to elicit activity in the parahippocampal gyrus, precuneus, inferior parietal cortex, and posterior midline regions. However, it is unknown whether involuntary memories are supported by the same mechanisms in PTSD. Because previous work has shown that both behavioral and neural responsivity is slowed in PTSD, we examined the spatiotemporal dynamics of the neural activity underlying negative and neutral involuntary memory retrieval.

Methods

Twenty-one individuals with PTSD and 21 non-PTSD, trauma-exposed controls performed an involuntary memory task, while undergoing a functional magnetic resonance imaging scan. Environmental sounds served as cues for well-associated pictures of negative and neutral scenes. We used a finite impulse response model to analyze temporal differences between groups in neural responses.

Results

Compared with controls, participants with PTSD reported more involuntary memories, which were more emotional and more vivid, but which activated a similar network of regions. However, compared to controls, individuals with PTSD showed delayed neural responsivity in this network and increased vmPFC/ACC activity for negative > neutral stimuli.

Conclusions

The similarity between PTSD and controls in neural substrates underlying involuntary memories suggests that, unlike voluntary memories, involuntary memories elicit similar activity in regions critical for memory retrieval. Further, the delayed neural responsivity for involuntary memories in PTSD suggests that factors affecting cognition in PTSD, like increased fatigue, or avoidance behaviors could do so by delaying activity in regions necessary for cognitive processing. Finally, compared to neutral memories, negative involuntary memories elicit hyperactivity in the vmPFC, whereas the vmPFC is typically shown to be hypoactive in PTSD during voluntary memory retrieval. These patterns suggest that considering both the temporal dynamics of cognitive processes as well as involuntary cognitive processes would improve existing neurobiological models of PTSD.

Repetitive TMS to augment cognitive processing therapy in combat veterans of recent conflicts with PTSD: A randomized clinical trial

BACKGROUND

The objective was to test whether repetitive Transcranial Magnetic Stimulation (rTMS) just prior to Cognitive Processing Therapy (CPT) would significantly improve the clinical outcome compared to sham rTMS prior to CPT in veterans with PTSD.

METHODS

Veterans 18-60 years of age with current combat-related PTSD symptoms were randomized, using a 1:1 ratio in a parallel design, to active (rTMS+CPT) versus sham (sham+CPT) rTMS just prior to weekly CPT for 12-15 sessions. Blinded raters evaluated veterans at baseline, after the 5th and 9th treatments, and at 1, 3, and 6 months post-treatment. Clinician Administered PTSD Scale (CAPS) was the primary outcome measure with the PTSD Checklist (PCL) as a secondary outcome measure. The TMS coil (active or sham) was positioned over the right dorsolateral prefrontal cortex (110% MT, 1Hz continuously for 30min, 1800 pulses/treatment).

RESULTS

Of the 515 individuals screened for the study, 103 participants were randomized to either active (n = 54) or sham rTMS (n = 49). Sixty-two participants (60%) completed treatment and 59 (57%) completed the 6-month assessment. The rTMS+CPT group showed greater symptom reductions from baseline on both CAPS and PCL across CPT sessions and follow-up assessments, t(df ≥ 325) ≤ -2.01, p ≤ 0.023, one-tailed and t(df ≥ 303) ≤ -2.14, p ≤ 0.017, one-tailed, respectively.

LIMITATIONS

Participants were predominantly male and limited to one era of conflicts as well as those who could safely undergo rTMS.

CONCLUSIONS

The addition of rTMS to CPT compared to sham with CPT produced significantly greater PTSD symptom reduction early in treatment and was sustained up to six months post-treatment.

Neuroimaging genetic approaches to Posttraumatic Stress Disorder

Neuroimaging genetic studies that associate genetic and epigenetic variation with neural activity or structure provide an opportunity to link genes to psychiatric disorders, often before psychopathology is discernable in behavior. Here we review neuroimaging genetics studies with participants who have Posttraumatic Stress Disorder (PTSD). Results show that genes related to the physiological stress response (e.g., glucocorticoid receptor and activity, neuroendocrine release), learning and memory (e.g., plasticity), mood, and pain perception are tied to neural intermediate phenotypes associated with PTSD. These genes are associated with and sometimes predict neural structure and function in areas involved in attention, executive function, memory, decision-making, emotion regulation, salience of potential threats, and pain perception. Evidence suggests these risk polymorphisms and neural intermediate phenotypes are vulnerabilities toward developing PTSD in the aftermath of trauma, or vulnerabilities toward particular symptoms once PTSD has developed. Work distinguishing between the re-experiencing and dissociative sub-types of PTSD, and examining other PTSD symptom clusters in addition to the re-experiencing and hyperarousal symptoms, will further clarify neurobiological mechanisms and inconsistent findings. Furthermore, an exciting possibility is that genetic associations with PTSD may eventually be understood through differential intermediate phenotypes of neural circuit structure and function, possibly underlying the different symptom clusters seen within PTSD.

Magnetic Resonance Therapy Improves Clinical Phenotype and EEG Alpha Power in Posttraumatic Stress Disorder

Background:

Posttraumatic stress disorder (PTSD) is a disabling and prevalent psychiatric disorder with limited effective treatment options. In addition to the clinical features of the disease, pathologic changes in the electroencephalogram (EEG), including decreased alpha power, have been reported.

Objectives:

To determine if magnetic brain stimulation can induce normalization of EEG abnormalities and improve clinical symptoms in PTSD in a preliminary, open-label evaluation.

Materials and Methods:

We reviewed prospectively-collected data on 21 veterans that were consecutively-treated for PTSD. Magnetic resonance therapy (MRT) was administered for two weeks at treatment frequencies based on frequency-domain analysis of each patient’s dominant alpha-band EEG frequencies and resting heart rate. Patients were evaluated on the PTSD checklist (PCL-M) and pre- and post-treatment EEGs before and after MRT.

Results:

Of the 21 patients who initiated therapy, 16 completed treatment. Clinical improvements on the PCL-M were seen in these 16 patients, with an average pre-treatment score of 54.9 and post-treatment score of 31.8 (P < 0.001). In addition, relative global EEG alpha-band (8 - 13 Hz) power increased from 32.0 to 38.5 percent (P = 0.013), and EEG delta-band (1 - 4 Hz) power decreased from 32.3 percent to 26.8 percent (P = 0.028).

Conclusions:

These open-label data show trends toward normalization of EEG and concomitant clinical improvement using magnetic stimulation for PTSD.

Neuronal Circuits for Fear Expression and Recovery: Recent Advances and Potential Therapeutic Strategies

Recent technological developments, such as single unit recordings coupled to optogenetic approaches, have provided unprecedented knowledge about the precise neuronal circuits contributing to the expression and recovery of conditioned fear behavior. These data have provided an understanding of the contributions of distinct brain regions such as the amygdala, prefrontal cortex, hippocampus, and periaqueductal gray matter to the control of conditioned fear behavior. Notably, the precise manipulation and identification of specific cell types by optogenetic techniques have provided novel avenues to establish causal links between changes in neuronal activity that develop in dedicated neuronal structures and the short and long-lasting expression of conditioned fear memories. In this review, we provide an update on the key neuronal circuits and cell types mediating conditioned fear expression and recovery and how these new discoveries might refine therapeutic approaches for psychiatric conditions such as anxiety disorders and posttraumatic stress disorder.

Seated movement indexes emotion and its regulation in posttraumatic stress disorder

This paper reports the results of a study that administered an emotion regulation task to Operation Enduring Freedom/Operation Iraqi Freedom veterans diagnosed with posttraumatic stress disorder (27) and to healthy controls (23). Seated movement and postural responses were transduced with a sensitive accelerometer attached to the underside of a low-mass cantilevered chair. Consistent with prior studies in which subjects stood on force plates, aversive photographs induced attenuation of nondirectional movement in patients and controls. Regarding seated postural responses, controls leaned towards neutral photographs and away from aversive ones, while participants with PTSD did the opposite. Regulation had no impact on seated movement but was associated with a seated postural withdrawal from the computer screen.

Fear extinction learning can be impaired or enhanced by modulation of the CRF system in the basolateral nucleus of the amygdala

The neuropeptide corticotropin-releasing factor (CRF) is released during periods of anxiety and modulates learning and memory formation. One region with particularly dense concentrations of CRF receptors is the basolateral nucleus of the amygdala (BLA), a critical structure for both Pavlovian fear conditioning and fear extinction. While CRF has the potential to modify amygdala-dependent learning, its effect on fear extinction has not yet been assessed. In the present study, we examined the modulatory role of CRF on within-session extinction and fear extinction consolidation. Intra-BLA infusions of the CRF binding protein ligand inhibitor CRF(6-33) which increases endogenous levels of free CRF, or intra-BLA infusions of exogenous CRF made prior to fear extinction learning did not affect either fear expression or within-session extinction learning. However, when these animals were tested twenty-four hours later, drug free, they showed impairments in extinction memory. Conversely, intra-BLA infusions of the CRF receptor antagonist α-helical CRF(9-41) enhanced memory of fear extinction. These results suggest that increased CRF levels within the BLA at the time of fear extinction learning actively impair the consolidation of long-term fear extinction.

Posterior Midline Activation during Symptom Provocation in Acute Stress Disorder: An fMRI Study

Functional imaging studies of patients with post-traumatic stress disorder showed wide-spread activation of midline cortical areas during symptom provocation, i.e., exposure to trauma-related cues. The present study aimed at investigating neural activation during exposure to trauma-related pictures in patients with acute stress disorder (ASD) shortly after the traumatic event. Nineteen ASD patients and 19 healthy control participants were presented with individualized pictures of the traumatic event and emotionally neutral control pictures during the acquisition of whole-brain data with a 3-T fMRI scanner. Compared to the control group and to control pictures, ASD patients showed significant activation in midline cortical areas in response to trauma-related pictures including precuneus, cuneus, postcentral gyrus, and pre-supplementary motor area. The results suggest that the trauma-related pictures evoke emotionally salient self-referential processing in ASD patients.

The effects of psychotherapy on brain function: a systematic and critical review

Over the past two decades, the development of neuroimaging techniques has allowed the non-invasive investigation of neuroplastic changes associated with psychotherapeutic treatment. The aim of the present article is to present a systematic and critical review of longitudinal studies addressing the impact of psychotherapy on the brain published to date. After summarizing the results reported in the literature for each psychiatric disorder separately (i.e. obsessive-compulsive disorder, panic disorder, unipolar major depressive disorder, posttraumatic stress disorder, specific phobia, schizophrenia), we discuss the results focusing on three questions of interest: (i) whether neurobiological changes which follow psychotherapy occur in regions that showed significant neurofunctional alteration pre-treatment; (ii) whether these neurobiological changes are similar, or different, to those observed following pharmacological treatment; and (iii) whether neurobiological changes could be used as an objective means of monitoring the progress and outcome of psychotherapy. The evidence reviewed indicates that (i) depending on the disorder under investigation, psychotherapy results in either a normalisation of abnormal patterns of activity, the recruitment of additional areas which did not show altered activation prior to treatment, or a combination of the two; (ii) the effects of psychotherapy on brain function are comparable to those of medication for some but not all disorders; and (iii) there is preliminary evidence that neurobiological changes are associated with the progress and outcome of psychotherapy. It is hoped that a better understanding of the impact of psychotherapy on brain function will eventually inform the development of new biologically informed treatments and allow clinicians to make more effective treatment decisions.

Low-frequency, Repetitive Transcranial Magnetic Stimulation for the Treatment of Patients with Posttraumatic Stress Disorder: a Double-blind, Sham-controlled Study

Objective

Several studies have suggested that repetitive transcranial magnetic stimulation (rTMS) of the right prefrontal cortex may be useful in the treatment of posttraumatic stress disorder (PTSD). The aim of this study was to compare the effect of rTMS on the right prefrontal cortex with that of sham stimulation among patients with PTSD.

Methods

In total, 18 patients with PTSD were randomly assigned to the 1-Hz low-frequency rTMS group or the sham group for 3 weeks. Primary efficacy measures were the Clinician-Administered PTSD Scale (CAPS) and its subscales, assessed at baseline and at 2, 4, and 8 weeks.

Results

All CAPS scores improved significantly over the study period. We found significant differences in the re-experiencing scores (F=7.47, p=0.004) and total scores (F=6.45, p=0.008) on the CAPS. The CAPS avoidance scores showed a trend toward significance (F=2.74, p=0.055), but no significant differences in the CAPS hyperarousal scores were observed.

Conclusion

The present study showed low-frequency rTMS to be an effective and tolerable option for the treatment of PTSD. Trials using variable indices of rTMS to the right prefrontal cortex and explorations of the differences in the effects on specific symptom clusters may be promising avenues of research regarding the use of rTMS for PTSD.

Current status on behavioral and biological markers of PTSD: a search for clarity in a conflicting literature

Extensive research has identified stereotypic behavioral and biological abnormalities in post-traumatic stress disorder (PTSD), such as heightened autonomic activity, an exaggerated startle response, reduced basal cortisol levels and cognitive impairments. We have reviewed primary research in this area, noting that factors involved in the susceptibility and expression of PTSD symptoms are more complex and heterogeneous than is commonly stated, with extensive findings which are inconsistent with the stereotypic behavioral and biological profile of the PTSD patient. A thorough assessment of the literature indicates that interactions among myriad susceptibility factors, including social support, early life stress, sex, age, peri- and post-traumatic dissociation, cognitive appraisal of trauma, neuroendocrine abnormalities and gene polymorphisms, in conjunction with the inconsistent expression of the disorder across studies, confounds attempts to characterize PTSD as a monolithic disorder. Overall, our assessment of the literature addresses the great challenge in developing a behavioral and biomarker-based diagnosis of PTSD.

Posttraumatic stress disorder: neurocircuitry and implications for potential deep brain stimulation

Posttraumatic stress disorder (PTSD) is a prevalent and highly disabling psychiatric disorder that is notoriously difficult to treat. At some point in their lifetimes, 5-8% of men, 10-14% of women, and up to a quarter of combat veterans carry this diagnosis. Despite pharmacological and behavioral therapies, up to 30% of patients are still symptomatic 10 years after initial diagnosis. Recent advances in imaging have implicated changes in the limbic and autonomic corticostriatopallidothalamocortical (CSPTC) circuitry in the pathogenesis of this disease. Deep brain stimulation modulates CSPTC circuits in movement and other neuropsychiatric disorders. In this review, we discuss the salient clinical features and neurocircuitry of PTSD and propose a neuromodulation strategy for the disorder.

In search of the trauma memory: a meta-analysis of functional neuroimaging studies of symptom provocation in posttraumatic stress disorder (PTSD)

Notwithstanding some discrepancy between results from neuroimaging studies of symptom provocation in posttraumatic stress disorder (PTSD), there is broad agreement as to the neural circuit underlying this disorder. It is thought to be characterized by an exaggerated amygdalar and decreased medial prefrontal activation to which the elevated anxiety state and concomitant inadequate emotional regulation are attributed. However, the proposed circuit falls short of accounting for the main symptom, unique among anxiety disorders to PTSD, namely, reexperiencing the precipitating event in the form of recurrent, distressing images and recollections. Owing to the technical demands, neuroimaging studies are usually carried out with small sample sizes. A meta-analysis of their findings is more likely to cast light on the involved cortical areas. Coordinate-based meta-analyses employing ES-SDM (Effect Size Signed Differential Mapping) were carried out on 19 studies with 274 PTSD patients. Thirteen of the studies included 145 trauma-exposed control participants. Comparisons between reactions to trauma-related stimuli and a control condition and group comparison of reactions to the trauma-related stimuli were submitted to meta-analysis. Compared to controls and the neutral condition, PTSD patients showed significant activation of the mid-line retrosplenial cortex and precuneus in response to trauma-related stimuli. These midline areas have been implicated in self-referential processing and salient autobiographical memory. PTSD patients also evidenced hyperactivation of the pregenual/anterior cingulate gyrus and bilateral amygdala to trauma-relevant, compared to neutral, stimuli. Patients showed significantly less activation than controls in sensory association areas such as the bilateral temporal gyri and extrastriate area which may indicate that the patients' attention was diverted from the presented stimuli by being focused on the elicited trauma memory. Being involved in associative learning and priming, the retrosplenial cortex may have an important function in relation to trauma memory, in particular, the intrusive reexperiencing of the traumatic event.

Heart rate after trauma and the specificity of fear circuitry disorders

BACKGROUND

Fear circuitry disorders purportedly include post-traumatic stress disorder (PTSD), panic disorder, agoraphobia, social phobia and specific phobia. It is proposed that these disorders represent a cluster of anxiety disorders triggered by stressful events and lead to fear conditioning. Elevated heart rate (HR) at the time of an aversive event may reflect strength of the unconditioned response, which may contribute to fear circuitry disorders.

METHOD

This prospective cohort study assessed HR within 48 h of hospital admission in 602 traumatically injured patients, who were assessed during hospital admission and within 1 month of trauma exposure for lifetime psychiatric diagnosis. At 3 months after the initial assessment, 526 patients (87%) were reassessed for PTSD, major depressive disorder, panic disorder, agoraphobia, social phobia, obsessive compulsive disorder and generalized anxiety disorder.

RESULTS

At the 3-month assessment there were 77 (15%) new cases of fear circuitry disorder and 87 new cases of non-fear circuitry disorder (17%). After controlling for gender, age, type of injury and injury severity, patients with elevated HR (defined as ≥96 beats per min) at the time of injury were more likely to develop PTSD [odds ratio (OR) 5.78, 95% confidence interval (CI) 2.32-14.43], panic disorder (OR 3.46, 95% CI 1.16-10.34), agoraphobia (OR 3.90, 95% CI 1.76-8.61) and social phobia (OR 3.98, 95% CI 1.42-11.14). Elevated HR also predicted new fear circuitry disorders that were not co-morbid with a non-fear circuitry disorder (OR 7.28, 95% CI 2.14-24.79).

CONCLUSIONS

These data provide tentative evidence of a common mechanism underpinning the onset of fear circuitry disorders.

Molecular modulation of prefrontal cortex: rational development of treatments for psychiatric disorders

Dysfunction of the prefrontal cortex (PFC) is a central feature of many psychiatric disorders, such as attention deficit hyperactivity disorder (ADHD), posttraumatic stress disorder (PTSD), schizophrenia, and bipolar disorder. Thus, understanding molecular influences on PFC function through basic research in animals is essential to rational drug development. In this review, we discuss the molecular signaling events initiated by norepinephrine and dopamine that strengthen working memory function mediated by the dorsolateral PFC under optimal conditions, and weaken working memory function during uncontrollable stress. We also discuss how these intracellular mechanisms can be compromised in psychiatric disorders, and how novel treatments based on these findings may restore a molecular environment conducive to PFC regulation of behavior, thought and emotion. Examples of successful translation from animals to humans include guanfacine for the treatment of ADHD and related PFC disorders, and prazosin for the treatment of PTSD.

The neural correlates of emotional memory in posttraumatic stress disorder

BACKGROUND

Posttraumatic stress disorder (PTSD) is marked by intrusive, chronic, and distressing memories of highly emotional events. Previous research has highlighted the role of the amygdala and its interactions with the hippocampus in mediating the effect of enhanced memory for emotional information in healthy individuals. As the functional integrity of these regions may be compromised in PTSD, the current study examined the neural correlates of emotional memory in PTSD.

METHODS

We used functional magnetic resonance imaging and an event-related subsequent memory recognition paradigm to study amygdala and hippocampus activation in 18 individuals with PTSD and 18 trauma-exposed non-PTSD control participants.

RESULTS

Memory enhancement for negative, relative to neutral, pictures was found across all subjects, without significant differences between groups. Relative to the trauma-exposed non-PTSD group, the PTSD group showed exaggerated amygdala activation during the encoding of negative versus neutral pictures. This effect was even more pronounced when the analysis included data from only pictures that were subsequently remembered 1 week later. In the PTSD group, degree of amygdala activation during the encoding of negative versus neutral pictures was positively correlated with hippocampal activation and current PTSD symptom severity. The PTSD group also showed exaggerated hippocampal activation in response to negative pictures that were remembered versus forgotten. Finally, hippocampal activation associated with the successful encoding of negative relative to neutral pictures was significantly greater in the PTSD group.

CONCLUSIONS

Exaggerated amygdala activation during the encoding of emotionally negative stimuli in PTSD is related to symptom severity and to hippocampal activation.

Successful use of stellate ganglion block and pulsed radiofrequency in the treatment of posttraumatic stress disorder: a case report

Objective. To report our successful treatment of acute symptoms of posttraumatic stress disorder (PTSD). By the use of stellate ganglion block (SGB) and pulsed radiofrequency (PRF) to the stellate ganglion(SG) , sequentially. Background. A 48-year-old male a victim of armed robbery , who presented with extreme symptoms consistent with the diagnosis of PTSD. He was treated with antianxiety medications, as well as psychotherapy, but his symptoms persisted. Methods. Fifty-five days post trauma, we administered a SGB to the patient. One month later, we administered PRF to the right SG . We repeated the pulsed radiofrequency 30 weeks post trauma and performed a second SGB two weeks after that. Results. After the SGB , the patient experienced a major reduction in anxiety. Over the next week his improved allowing a significant reduction of antianxiety medications. One month later the symptoms returned and again subsided substantially following PRF , and that relief lasted four months. The patient than required another following PRF and a SGB with good responses. Conclusion. We report that selective blockade of the stellate ganglion via injection and the treatment with PRF, relieved our patient's symptoms of PTSD. And we also provide a plausible explanation of the effect.

Fear conditioning and early life vulnerabilities: two distinct pathways of emotional dysregulation and brain dysfunction in PTSD

The newly proposed criteria for posttraumatic stress disorder (PTSD) in the Diagnostic and Statistical Manual (DSM-V) include dysregulation of a variety of emotional states including fear, anger, guilt, and shame, in addition to dissociation and numbing. Consistent with these revisions, we postulate two models of emotion dysregulation in PTSD in which fear is not the prevailing emotion but is only one of several components implicated in a dysregulated emotional system that also mediates problems regulating anger, guilt, shame, dissociation, and numbing.We discuss whether there is a relationship between fear and other emotion regulation systems that may help further our understanding of PTSD and its underlying neurocircuitry. Two pathways describing the relationship between fear and other emotion regulation systems in PTSD are proposed. The first pathway describes emotion dysregulation as an outcome of fear conditioning through stress sensitization and kindling. The second pathway views emotion dysregulation as a distal vulnerability factor and hypothesizes a further exacerbation of fear and other emotion regulatory problems, including the development of PTSD after exposure to one or several traumatic event(s) later in life. Future research and treatment implications are discussed.

Viral vector induction of CREB expression in the periaqueductal gray induces a predator stress-like pattern of changes in pCREB expression, neuroplasticity, and anxiety in rodents

Predator stress is lastingly anxiogenic. Phosphorylation of CREB to pCREB (phosphorylated cyclic AMP response element binding protein) is increased after predator stress in fear circuitry, including in the right lateral column of the PAG (periaqueductal gray). Predator stress also potentiates right but not left CeA-PAG (central amygdala-PAG) transmission up to 12 days after stress. The present study explored the functional significance of pCREB changes by increasing CREB expression in non-predator stressed rats through viral vectoring, and assessing the behavioral, electrophysiological and pCREB expression changes in comparison with handled and predator stressed controls. Increasing CREB expression in right PAG was anxiogenic in the elevated plus maze, had no effect on risk assessment, and increased acoustic startle response while delaying startle habituation. Potentiation of the right but not left CeA-PAG pathway was also observed. pCREB expression was slightly elevated in the right lateral column of the PAG, while the dorsal and ventral columns were not affected. The findings of this study suggest that by increasing CREB and pCREB in the right lateral PAG, it is possible to produce rats that exhibit behavioral, brain, and molecular changes that closely resemble those seen in predator stressed rats.

Infusing neuroscience into the study and prevention of drug misuse and co-occurring aggressive behavior

The etiology of behavioral precursors to substance misuse and aggression is viewed from the perspective of a developmental, multifactorial model of complex disorders. Beginning at conception, genetic and environmental interactions have potential to produce a sequence of behavioral phenotypes during development that bias the trajectory toward high-risk outcomes. One pathway is theorized to emanate from a deviation in neurological development that predisposes children to affective and cognitive delays or impairments that, in turn, generate dysregulatory behaviors. The plasticity of these neurobiological systems is highly relevant to the prevention sciences; their functions are reliant upon environmental inputs and can be altered, for better or for worse, contingent upon the nature of the inputs. Thus, social contextual factors confer significant influence on the development of this neural network and behavioral outcomes by increasing risk for, or protecting (1) against, dysregulatory outcomes. A well-designed intervention can exploit the brain's plasticity by targeting biological and social factors at sensitive time points to positively influence emergent neurobiological functions and related behaviors. Accordingly, prevention research is beginning to focus on perturbations in developmental neural plasticity during childhood that increase the likelihood of risky behaviors and may also moderate intervention effects on behavior. Given that the more complex features of neurobiological functions underlying drug misuse and aggression (e.g., executive cognitive function, coping skills, affect regulation) do not coalesce until early adulthood when prefrontal-limbic brain networks consolidate, it is critical that mechanisms underlying developmental risk factors are identified. An empirically driven prevention approach, thus, may benefit from consideration of (i) the type, effect, and developmental timing of the environmental impact on the brain, and (ii) the type and effect on brain function, and developmental timing of the intervention. This translational approach promises to eventually offer some direction for the design of effective interventions to prevent drug misuse and concomitant aggression.

Vulnerability to lasting anxiogenic effects of brief exposure to predator stimuli: sex, serotonin and other factors-relevance to PTSD

Lasting anxiogenic effects of predator stress in rodents may model aspects of post-traumatic stress disorder (PTSD). There is a link between genetic variation in the serotonin (5-HT) transporter (SERT) and anxiety in humans, prompting the generation of SERT knockout mice. This review brings together studies of SERT knockout male mice, normal female mice, and different 5-HT receptors in predator stress effects on anxiety. These studies provide for a link between vulnerability to the anxiogenic effects of predator stress and abnormalities of 5-HT transmission induced by a life long reduction in 5-HT reuptake in male mice, which creates a vulnerability like that seen in normal female mice. Data reviewed suggest abnormalities in 5-HT transmission contribute to vulnerability to lasting anxiogenic effects of species relevant stressors. To the extent to which predator stress effects model aspects of PTSD, and in the light of relevant human literature, these considerations implicate abnormalities of 5-HT transmission in vulnerability to PTSD per se, and as a potential contributor to enhanced female vulnerability to PTSD.

The role of the read through variant of acetylcholinesterase in anxiogenic effects of predator stress in mice

This study examined the role of the read through variant of acetylcholinesterase (AChE-R) in lasting changes in murine affective behavior produced by a brief predator stress. AChE-R is elevated by stress in limbic cholinergic circuits implicated in anxiogenic effects of predator stress. The expression of AChE-R was blocked with a systemically administered central acting antisense oligonucleotide for AChE-R (EN101). EN101 was injected at multiple points prior to and after a predator stress in male C57 mice. Seven days after the last injection, behavior was tested. Predator stress caused a significant increase in startle amplitude, which EN101 blocked. This effect was specific to EN101, as the negative control inactive form of EN101, INVEN101 was without effect on stress effects on startle. Neither EN101 nor INVEN101 altered the anxiogenic effects of predator stress on behavior in the elevated plus maze, and both drugs partially reduced stress suppression of time active in the hole board. In the light dark box test, INVEN101 exhibited a weak block of stress effects on behavior for reasons which are unclear. Taken together, findings support the view that multiple neural systems are responsible for the different changes in behavior produced by predator stress. Present findings also suggest a role for AChE-R in specific anxiogenic (hyperarousal) effects following predator stress. Since AChE-R manipulations took place starting 23 h prior to predator stress and continued 48 h after predator stress, further research is necessary to determine the role of AChE-R in initiation and/or consolidation of hyperarousal effects of predator stress.

Altered oscillatory brain dynamics after repeated traumatic stress

BACKGROUND

Repeated traumatic experiences, e.g. torture and war, lead to functional and structural cerebral changes, which should be detectable in cortical dynamics. Abnormal slow waves produced within circumscribed brain regions during a resting state have been associated with lesioned neural circuitry in neurological disorders and more recently also in mental illness.

METHODS

Using magnetoencephalographic (MEG-based) source imaging, we mapped abnormal distributions of generators of slow waves in 97 survivors of torture and war with posttraumatic stress disorder (PTSD) in comparison to 97 controls.

RESULTS

PTSD patients showed elevated production of focally generated slow waves (1-4 Hz), particularly in left temporal brain regions, with peak activities in the region of the insula. Furthermore, differential slow wave activity in right frontal areas was found in PTSD patients compared to controls.

CONCLUSION

The insula, as a site of multimodal convergence, could play a key role in understanding the pathophysiology of PTSD, possibly accounting for what has been called posttraumatic alexithymia, i.e., reduced ability to identify, express and regulate emotional responses to reminders of traumatic events. Differences in activity in right frontal areas may indicate a dysfunctional PFC, which may lead to diminished extinction of conditioned fear and reduced inhibition of the amygdala.

The neurofunctional mechanisms of traumatic and non-traumatic memory in patients with acute PTSD following accident trauma

Neurofunctional alterations in acute posttraumatic stress disorder (PTSD) and changes thereof during the course of the disease are not well investigated. We used functional magnetic resonance imaging to assess the functional neuroanatomy of emotional memory in surgical patients with acute PTSD. Traumatic (relative to non-traumatic) memories increased neural activity in the amygdala, hippocampus, lateral temporal, retrosplenial, and anterior cingulate cortices. These regions are all implicated in memory and emotion. A comparison of findings with data on chronic PTSD suggests that brain circuits affected by the acute disorder are extended and unstable while chronic disease is characterized by circumscribed and stable neurofunctional abnormalities.

Involvement of noradrenergic and corticoid receptors in the consolidation of the lasting anxiogenic effects of predator stress

The roles of beta-NER (beta-noradrenergic receptor), GR (glucocorticoid) and mineral corticoid receptors (MR) in the consolidation of anxiogenic effects of predator stress were studied. One minute after predator stress, different groups of rats were injected (ip) with vehicle, propranolol (beta-NER blocker, 5 and 10 mg/kg), mifepristone (RU486, GR blocker, 20 mg/kg), spironolactone (MR blocker, 50 mg/kg), propranolol (5 mg/kg) plus RU486 (20 mg/kg) or the anxiolytic, chloradiazepoxide (CPZ, 10 mg/kg). One week later, rodent anxiety was assessed in elevated plus maze, hole board, light/dark box, social interaction and acoustic startle. Considering all tests except startle, propranolol dose dependently blocked consolidation of lasting anxiogenic effects of predator stress in all tests. GR receptor block alone was ineffective. However, GR block in combination with an ineffective dose of propranolol did blocked consolidation of predator stress effects in all tests, suggesting a synergism between beta-NER and GR. Surprisingly, MR block prevented consolidation of anxiogenic effects in all tests except the light/dark box. CPZ post stress was ineffective against the anxiogenic impact of predator stress. Study of startle was complicated by the fact that anxiogenic effects of stress on startle amplitude manifested as both an increase and a decrease in startle amplitude. Suppression of startle occurred in stressed plus vehicle injected groups handled three times prior to predator stress. In contrast, stressed plus vehicle rats handled five times prior to predator stress showed increases in startle, as did all predator stressed only groups. Mechanisms of consolidation of the different startle responses appear to differ. CPZ post stress blocked startle suppression but not enhancement of startle. Propranolol post stress had no effect on either suppression or enhancement of startle. GR block alone post stress prevented suppression of startle, but not enhancement. In contrast blocking GR and beta-NER together prevented startle enhancement. MR block also prevented startle enhancement. Effects of MR block on startle suppression were not tested. Delay of habituation to startle was found in all stressed rats. Consolidation of delay of habituation was blocked or attenuated by post stress MR block, GR plus beta-NER block and CPZ but not by post stress GR or beta-NER block alone. Taken together, present findings suggest consolidation of lasting anxiogenic effects of predator stress may share some of the same neurochemical mechanisms implicated in some forms of fear memory consolidation. Implications of these findings for the study of stress-induced changes in affect including posttraumatic stress disorder (PTSD) are discussed.

The NMDA receptor antagonist CPP blocks the effects of predator stress on pCREB in brain regions involved in fearful and anxious behavior

A 5-min unprotected exposure to a cat produces long-lasting anxiogenic effects on behavior which are NMDA receptor-dependent. Since phosphorylation of CREB is regulated by NMDA receptors and pCREB-like-immunoreactivity (lir) is increased after predator stress, we examined the effects of CPP (3-(2-carboxypiperazin4-yl)propyl-l-phosphonic acid), a competitive NMDA receptor antagonist, on predator stress-induced changes in pCREB-lir in brain areas implicated in fearful and anxious behavior. Areas examined included the amygdala, periqueductal gray (PAG), bed nucleus of the stria terminalis (BNST), anterior cingulate cortex (ACC), and dorsal medial hypothalamus (DMH). CPP blocked the predator stress-induced increase in pCREB-lir in the right lateral PAG and in several amygdala nuclei. CPP also reversed the predator stress-induced suppression of pCREB-lir in the BNST. Importantly, at least in the amygdala and PAG, the pattern of pCREB-lir was hemisphere- and AP plane-dependent. Our results suggest that several amygdala nuclei, the PAG, and the BNST, where predator stress changes pCREB-lir in a NMDA receptor-dependent manner, are candidate areas of neuroplastic change contributing to lasting changes in anxiety-like behaviors.

Hippocampus function predicts severity of post-traumatic stress disorder

Post-traumatic stress disorder (PTSD) is often accompanied by memory problems and abnormal brain structure, particularly within the hippocampus. We implemented a cross-species, hippocampal-dependent task--the virtual Morris Water task--to assess hippocampal function in people with PTSD and age-matched controls during functional magnetic resonance imaging (fMRI). Performance on the task was equivalent between the groups. However, when correlating fMRI-derived hippocampal activity during this task with PTSD severity, we observe a -0.84 correlation, indicating that those with reduced hippocampal activity show more severe PTSD symptoms. This correlation is not explained by differences in task performance, IQ, duration since trauma, nor time with PTSD. Hence, PTSD severity is predicted by functionally assessing the hippocampus using the virtual Morris water task, suggesting that this task may be used to identify those at risk for developing PTSD following a trauma.

Amygdala, medial prefrontal cortex, and hippocampal function in PTSD

The last decade of neuroimaging research has yielded important information concerning the structure, neurochemistry, and function of the amygdala, medial prefrontal cortex, and hippocampus in posttraumatic stress disorder (PTSD). Neuroimaging research reviewed in this article reveals heightened amygdala responsivity in PTSD during symptomatic states and during the processing of trauma-unrelated affective information. Importantly, amygdala responsivity is positively associated with symptom severity in PTSD. In contrast, medial prefrontal cortex appears to be volumetrically smaller and is hyporesponsive during symptomatic states and the performance of emotional cognitive tasks in PTSD. Medial prefrontal cortex responsivity is inversely associated with PTSD symptom severity. Lastly, the reviewed research suggests diminished volumes, neuronal integrity, and functional integrity of the hippocampus in PTSD. Remaining research questions and related future directions are presented.

A twin study of posttraumatic stress disorder symptoms and chronic widespread pain

Previous studies of the association between posttraumatic stress disorder (PTSD) and chronic widespread pain (CWP) or fibromyalgia have not examined the role of familial or genetic factors. The goals of this study were to determine if symptoms of PTSD are related to CWP in a genetically informative community-based sample of twin pairs, and if so, to ascertain if the association is due to familial or genetic factors. Data were obtained from the University of Washington Twin Registry, which contains 1042 monozygotic and 828 dizygotic twin pairs. To assess the symptoms of PTSD, we used questions from the Impact of Events Scale (IES). IES scores were partitioned into terciles. CWP was defined as pain located in 3 body regions lasting at least 1 week during the past 3 months. Random-effects regression models, adjusted for demographic features and depression, examined the relationship between IES and CWP. IES scores were strongly associated with CWP (P<0.0001). Compared to those in the lowest IES tercile, twins in the highest tercile were 3.5 times more likely to report CWP. Although IES scores were associated with CWP more strongly among dizygotic than among monozygotic twins, this difference was not significant. Our findings suggest that PTSD symptoms, as measured by IES, are strongly linked to CWP, but this association is not explained by a common familial or genetic vulnerability to both conditions. Future research is needed to understand the temporal association of PTSD and CWP, as well as the physiological underpinnings of this relationship.

Cognitive therapy for irritable bowel syndrome is associated with reduced limbic activity, GI symptoms, and anxiety

This study sought to identify brain regions that underlie symptom changes in severely affected IBS patients undergoing cognitive therapy (CT). Five healthy controls and 6 Rome II diagnosed IBS patients underwent psychological testing followed by rectal balloon distention while brain neural activity was measured with O-15 water positron emission tomography (PET) before and after a brief regimen of CT. Pre-treatment resting state scans, without distention, were compared to post-treatment scans using statistical parametric mapping (SPM). Neural activity in the parahippocampal gyrus and inferior portion of the right cortex cingulate were reduced in the post-treatment scan, compared to pre-treatment (x, y, z coordinates in MNI standard space were -30, -12, -30, P=0.017; 6, 34, -8, P=0.023, respectively). Blood flow values at these two sites in the controls were intermediate between those in the pre- and post-treatment IBS patients. Limbic activity changes were accompanied by significant improvements in GI symptoms (e.g., pain, bowel dysfunction) and psychological functioning (e.g., anxiety, worry). The left pons (-2, -26, -28, P=0.04) showed decreased neural activity which was correlated with post-treatment anxiety scores. Changes in neural activity of cortical-limbic regions that subserve hypervigilance and emotion regulation may represent biologically oriented change mechanisms that mediate symptom improvement of CT for IBS.

Psychosocial aspects of the functional gastrointestinal disorders

This report reviews recent research on the psychosocial aspects of the functional gastrointestinal disorders (FGIDs). A review and evaluation of existing literature was conducted by a multidisciplinary committee of experts in this field. This report is a synopsis of a chapter published in the Rome III book. The committee reached consensus in finding considerable evidence supporting the association between psychological distress, childhood trauma and recent environmental stress, and several of the FGIDs but noted that this association is not specific to FGIDs. There is also considerable evidence that psychosocial variables are important determinants of the outcomes of global well-being, health-related quality of life, and health care seeking. In line with these descriptive findings, there is now increasing evidence that a number of psychological treatments and antidepressants are helpful in reducing symptoms and other consequences of the FGIDs in children and adults. The FGIDs are a result of complex interactions between biological, psychological, and social factors, and they can only be treated satisfactorily when all these factors are considered and addressed. Therefore, knowledge about the psychosocial aspects of FGIDs is fundamental and critical to the understanding, assessment, and treatment of these disorders. More extensive physician training is needed if these aspects of treatment are to be used effectively and widely in clinical practice.

Alterations in cerebral perfusion in posttraumatic stress disorder patients without re-exposure to accident-related stimuli

Functional neuroimaging studies have shown abnormalities of limbic regions in patients with posttraumatic stress disorder (PTSD) during symptom provocation and cognitive activation.

OBJECTIVE

The aim of this study was to determine whether PTSD patients without re-exposure to accident-related stimuli would exhibit alterations in cerebral perfusion compared with age-matched normal subjects.

METHODS

Brain perfusion SPECT was measured in medication-free 23 PTSD patients and 64 age-matched healthy subjects under resting conditions and analyzed using statistical parametric mapping to compare between the patient and control groups.

RESULTS

We found that PTSD patients exhibited increased cerebral blood perfusion in limbic regions and decreased perfusion in the superior frontal gyrus and parietal and temporal regions in comparison with those of the normal controls.

CONCLUSIONS

This result indicates that PTSD patients have alterations in cerebral perfusion of limbic regions and the frontal and temporal cortex without re-exposure to accident-related stimuli.

SIGNIFICANCE

This finding supports the hypothesis of the involvement of limbic regions, which might be associated with the regulation of emotion and memory, in the pathophysiology of PTSD.

Relationship of the predatory attack experience to neural plasticity, pCREB expression and neuroendocrine response

Aggression takes at least two, an attacker and a target. This paper will address the lasting consequences of being a target of aggression. We review the lasting impact of predatory attack on brain and behavior in rodents. A single brief unprotected exposure of a rat to a cat lastingly alters affective responses of rats in a variety of contexts. Alterations of these behaviors resembles both generalized anxiety comorbid with post traumatic stress disorder (PTSD), and the hyper arousal expressed in enhanced startle in PTSD. Examination of neural transmission and neural plasticity in limbic circuits implicates changes in transmission in two connecting pathways in many but not all of the behavioral changes. Quantification of the predator encounter reveals that both the behavior of the predator and the reaction of the rat to attack are highly predictive of the effects of predatory attack on molecular biological (pCREB expression) and electrophysiological measures of limbic neuroplastic change. Moreover, a case will be made that the pattern of change of corticosteroid level over three hours after the predator encounter, in interaction with the predatory experience, plays an important part in initiation of lasting changes in brain and behavior.

Cortico-amygdala circuits: role in the conditioned stress response

The amygdala plays a crucial role in the orchestration and modulation of the organism response to aversive, stressful events. This response could be conceived as the result of two interdependent components. The first is represented by sets of visceral and motor responses aimed at helping the organism to cope with the present event. The second is the acquisition and modulation of memories relative to the stressful stimulus and its context. This latter component contributes to the instatement of conditioned stress responses that are essential to the capability of the organism to predict future exposures to similar stimuli in order to avoid them or counteract them effectively. In the amygdala, these two components become fully integrated. Massive networks link the amygdala to the hypothalamus, midbrain and brainstem. These networks convey visceral, humoral and nociceptive information to the amygdala and mediate its effects on the hypothalamic-pituitary-adrenal axis as well on autonomic and motor centers. On the other hand, interactions between the amygdala and interconnected cortical networks play a crucial role in acquisition, consolidation and extinction of learning relative to the stressful stimulus. Within the scope of this review, current evidence relative to the interaction between the amygdala and cortical networks will be considered in relationship to the integration of the conditioned response to stress.

Role of NMDA receptors in the lateralized potentiation of amygdala afferent and efferent neural transmission produced by predator stress

The present study investigated the role of NMDA receptors in behavioral and neuroplastic changes in amygdala efferent (central amygdala to periaqueductal gray-ACE-PAG) and amygdala afferent (ventral angular bundle to basolateral amygdala-VAB-BLA) pathways in response to predator stress. Effects on brain and behavioral response to predator stress of competitive block of NMDA receptors with a dose of 10 mg/kg of CPP (3-(2-carboxypiperazin4-yl)propyl-l-phosphonic acid) were studied. Behavioral response to stress was tested with hole board, elevated plus maze, light/dark box, social interaction and acoustic startle tests. CPP was administered i.p. 30 min prior to predator stress and blocked the effects of predator on some but not all behaviors measured 8-9 days later. Effects of predator stress and CPP on potentials evoked in the PAG by single pulse stimulation of the ACE and in the BLA by single pulse stimulation of VAB were assessed 10-11 days after predator stress. Predator stress potentiated ACE-PAG evoked potentials in the right but not the left hemisphere, replicating previous work. Predator stress potentiated VAB-BLA transmission in both hemispheres 10-11 days after predator stress. Right hemisphere VAB-BLA potentiation replicated and extended past studies showing right hemisphere potentiation at 1 and 9 days after stress. Left VAB-BLA potentiation effects differed from the long term depression seen in VAB-BLA at 1 and 9 days after stress in previous studies. CPP blocked predator stress-induced potentiation of ACE-PAG and VAB-BLA evoked potentials in the right hemisphere. CPP did not block left VAB-BLA potentiation, rather CPP amplified it. Left hemisphere effects of CPP were interpreted as reflecting block of NMDA dependent long term depression, which unmasked a non-NMDA dependent potentiation. Taken together, the findings add to a body of evidence suggesting that a syndrome of behavioral changes follows predator stress. Components of this syndrome likely depend on changes in separable neural substrates. Potentiation of ACE-PAG and VAB-BLA evoked potentials in the right hemisphere likely mediates a subset of changes in behavior. Moreover, a medial ACE-PAG pathway is implicated in mediating stress-induced changes in startle amplitude. In contrast, a lateral ACE-PAG pathway is implicated in mediating changes in startle habituation. Finally, consistent with cat and human studies, the right hemisphere appears particularly important in long term response to stress.

Neural circuit changes mediating lasting brain and behavioral response to predator stress

This paper reviews recent work which points to critical neural circuitry involved in lasting changes in anxiety like behavior following unprotected exposure of rats to cats (predator stress). Predator stress may increase anxiety like behavior in a variety of behavioral tests including: elevated plus maze, light dark box, acoustic startle, and social interaction. Studies of neural transmission in two limbic pathways, combined with path and covariance analysis relating physiology to behavior, suggest long term potentiation like changes in one or both of these pathways in the right hemisphere accounts for stress induced changes in all behaviors changed by predator stress except light dark box and social interaction. Findings will be discussed within the context of what is known about neural substrates activated by predator odor.

Effects of cognitive-behavioral therapy on brain activation in specific phobia

Little is known about the effects of successful psychotherapy on brain function in subjects with anxiety disorders. The present study aimed to identify changes in brain activation following cognitive-behavioral therapy (CBT) in subjects suffering from specific phobia. Using functional magnetic resonance imaging (fMRI), brain activation to spider videos was measured in 28 spider phobic and 14 healthy control subjects. Phobics were randomly assigned to a therapy-group (TG) and a waiting-list control group (WG). Both groups of phobics were scanned twice. Between scanning sessions, CBT was given to the TG. Before therapy, brain activation did not differ between both groups of phobics. As compared to control subjects, phobics showed greater responses to spider vs. control videos in the insula and anterior cingulate cortex (ACC). CBT strongly reduced phobic symptoms in the TG while the WG remained behaviorally unchanged. In the second scanning session, a significant reduction of hyperactivity in the insula and ACC was found in the TG compared to the WG. These results propose that increased activation in the insula and ACC is associated with specific phobia, whereas an attenuation of these brain responses correlates with successful therapeutic intervention.

Relationship between post-traumatic stress disorder and pain in two American Indian tribes

OBJECTIVES

To estimate the association of lifetime post-traumatic stress disorder (PTSD) and pain in American Indians, and determine if tribe, sex, cultural and psychosocial factors, or major depression influence the magnitude of this association.

DESIGN

A cross-sectional probability sample survey completed between 1997 and 2000. A structured interview was conducted by trained, tribal members to gather information on demographic and cultural features, physical health status, psychiatric disorders, and functional status.

SETTING

General community.

PARTICIPANTS

A total of 3,084 individuals randomly selected from the tribal rolls of a Southwestern (N = 1,446) and a Northern Plains (N = 1,638) tribal group who were 15-54 years of age and lived on or within 20 miles of their reservations.

OUTCOME MEASURES

Bodily pain subscale of the Short Form-36. Linear regression models were fit to examine the association between lifetime PTSD and pain, adjusting for demographic, cultural, psychosocial features, painful medical conditions, and major depression.

RESULTS

The prevalence of lifetime PTSD was 16% in the Southwestern and 14% in the Northern Plains; women were nearly twice as likely as men to have lifetime PTSD in both tribes. The final adjusted model demonstrated that mean Short Form-36 bodily pain subscale scores were lower (indicating more pain) among individuals with lifetime PTSD than those without lifetime PTSD. Effect modification by tribe, sex, and depression was not observed.

CONCLUSIONS

Lifetime PTSD was strongly associated with bodily pain in this rural sample of American Indians. Clinicians should be aware of, and address, the link between physical pain syndromes and PTSD.

Sleep in post-traumatic stress disorder and panic: convergence and divergence

Disturbed sleep is a common clinical problem in anxiety disorders, particularly in patients with post-traumatic stress disorder (PTSD) and panic disorder (PD). Several studies have attempted to validate the subjective sleep complaints of these disorders using laboratory polysomnography. These attempts, typically focusing on PTSD or PD independently, have demonstrated inconsistent results. To our knowledge, no such studies have attempted to directly compare and contrast sleep disturbances in PTSD and PD together. Our review of the studies of subjective sleep disturbances, sleep architecture, and sleep-related biologic phenomena suggests that a comparative characterization of sleep disturbances in these two disorders is timely. Such an inference is based on our identification of several areas of convergence and divergence between PTSD and PD found in the published literature, as well as our own preliminary investigations. Specifically, PTSD and PD seem to converge on several sleep-related parameters, namely, sleep quality, presence of episodic parasomnias, and movement time. They also appear to diverge in other important sleep-related areas such as respiratory disturbances and the particular phenomenological nature of episodic parasomnias, namely nightmares or nocturnal panic attacks. Investigations focusing on such overlapping phenomena may provide groundwork for further elucidation of central fear systems underlying these two disorders. Additionally, such sleep studies have the potential to provide important insights into ongoing efforts to develop a cohesive conceptual framework into the patho-physiologies of these disorders.

Adaptive and maladaptive psychobiological responses to severe psychological stress: implications for the discovery of novel pharmacotherapy

Post-traumatic stress disorder (PTSD) is one of the few DSM-IV diagnoses contingent upon a psychosocial stressor. In this context, there is an urgent need to acquire a better understanding of both the adaptive and maladaptive psychobiological responses to traumatic stress. Preclinical investigators have utilized a variety of animal models to identify the behavioral and neurobiological features of the organism's response to stress. However, given the complexity of the healthy and pathological human response to physiological and psychological stress, the extent to which the animal data is immediately transferable to human remains to be fully determined. This review draws upon preclinical and clinical literature to examine the transformation of an adaptive human stress response into a maladaptive and debilitating mental disorder. An integrative psychobiological model for PTSD is presented, linking psychological processes and behavioral patterns with current findings in neurocircuitry, neurochemistry and psychophysiology. The implications of this model for the discovery of novel pharmacological approaches to the treatment of severe psychological distress are discussed.

Functional connectivity of the prefrontal cortex and the amygdala in posttraumatic stress disorder

BACKGROUND

Persistent, intrusive re-experiencing in posttraumatic stress disorder (PTSD) is commonly construed as a failure of cingulate inhibition (i.e., extinction) over a hyperresponsive amygdala, based primarily on animal research of fear conditioning and the finding of cingulate hypoperfusion in PTSD.

METHODS

We examined functional connectivity in patients with PTSD and healthy trauma survivors during repeated symptom provocation using H(2)O(15) positron emission tomography.

RESULTS

Memory retrieval networks (right prefrontal cortex, hippocampus, and visual cortex) were common to both groups. Networks supporting autonomic and emotional control and preparatory motor action (amygdala, anterior cingulate, subcallosal gyrus, and premotor cortex) differed between the two groups and became progressively disparate with successive presentations of the traumatic script. Patterns of effective connectivity demonstrated the predominance of direct influences of the amygdala on visual cortex, subcallosal gyrus, and anterior cingulate in PTSD but not in control subjects. There was little evidence for failure of inhibition of cingulate or subcallosal cortex over the amygdala.

CONCLUSIONS

These patterns might represent excessive influences of the amygdala over regions involved in autonomic, and higher-order visual memory processing in PTSD. The present data suggest that inferences of direct correspondence between animal studies and pathophysiology of PTSD should be made with caution.

Phosphorylated cyclic AMP response element binding protein expression induced in the periaqueductal gray by predator stress: its relationship to the stress experience, behavior and limbic neural plasticity

Electrophysiological studies in cats and recently in rats implicate neuroplasticity in the periaqueductal gray (PAG) and its afferents in stressor-induced increases in fearful behavior and anxiety-like behavior (ALB). Such increases may model aspects of affective changes following traumatic stress in humans. The present study explored the role of neuroplasticity in PAG and its connection with the central nucleus of the amygdala (ACE) in male rodent anxiety-like response to predator stress. In the first of two studies, the effects of predator stress on the induction of phosphorylated cyclic AMP response element binding protein (pCREB) were investigated. pCREB expression in the PAG and ventromedial hypothalamus (VMH) was examined immunohistochemically. Predator stress increased the degree of pCREB expression in PAG cells (measured densitometrically) but did not increase the number of cells expressing pCREB (measured stereologically). Moreover, predator stress-specific increase in pCREB-like immunoreactivity (lir) was restricted to the right lateral column of the PAG. In addition, pCREB lir in the right lateral column likely reflects aspects of the stress experience because the stressor (cat behavior) and the response to the stressor (rat defensive behavior) are highly predictive of degree of pCREB expression. There was no effect of predator stress on pCREB lir in the VMH. Because pCREB expression has been associated with long-lasting potentiation (LLP) of neural transmission, we examined the effects of predator stress on transmission in the ACE-PAG pathway in a second study. Predator stress elevated evoked potential measures of ACE-PAG transmission in the right hemisphere but not in the left hemisphere 11-12 days after predator stress. This finding is consistent with the longer-lived effects of pharmacological stress on amygdalo-PAG transmission in the right hemisphere but not in the left hemisphere in cats. Of interest is the fact that the same aspects of the stressor experience and reaction to it, which are predictive of the degree of pCREB expression, are also highly predictive of the degree of potentiation of measures of ACE-PAG transmission. Behavioral analyses revealed that the most consistent effects of predator stress are on behavior in the plus maze (open arm exploration and risk assessment) and on startle. In addition, covariance analysis suggests that ACE-PAG potentiation mediates some but not all of the changes in ALB produced by predator stress. Because pCREB expression may be a precursor to neuroplastic changes in certain forms of memory and LLP, the present findings complement studies in the cat, showing that neuroplastic changes in the PAG underlie changes in affect following stress. Furthermore, these findings suggest that neuroplastic changes in PAG may be important mediators of predator stress-induced changes in affective behavior in rodents. Finally, consistent with cat and human studies, the right hemisphere appears particularly important in long-term response to stress.