Potential role of the anterior cingulate cortex in PTSD: Review and hypothesis

Psychological impact of trauma on developing children and youth

All too often, children and adolescents are exposed to traumatic events that lead to physical injury in many cases, psychological perturbation in most cases, and enduring psychological reactions, notably posttraumatic stress disorder, in a minority of individuals. This sequence of events can affect later development, learning, emotions, and behavior. In the process of caring for the physical injury, it is important for the primary care practitioner (PCP) to correctly interpret these presentations and anticipate the need for specific assessments, immediate intervention, referral, and follow-up. This report provides the foundation for such actions on the part of the PCP.

Asymmetrically altered integrity of cingulum bundle in posttraumatic stress disorder

Previously, our group reported the altered white matter tract integrity of the left anterior cingulate in posttraumatic stress disorder (PTSD) in whole-brain exploration. Current study intended to explore whether the alteration was more prominent in any specific regions of the cingulum bundle. Diffusion tensor images of 21 PTSD subjects and 21 healthy comparison subjects were acquired. Eight isocubic regions of interest (ROIs), i.e. bilateral rostral, subgenual, dorsal, and upper cingulum bundle, were selected. Fractional anisotropy values in each ROI, which indicate the white matter tract integrity, were measured and compared between groups. Relative to comparison subjects, PTSD subjects had significantly smaller fractional anisotropy values in the left side of rostral, subgenual and dorsal cingulum bundle (26.7, 25.0, 22.2% decrease, respectively), but not in the right side ROIs. We report an asymmetrical alteration of the cingulum bundle in PTSD.

Apoptotic changes in the cortex and hippocampus following minimal brain trauma in mice

Interpretation of the cellular and molecular pathogenic basis of post-minimal traumatic brain injury is a significant clinical and scientific problem, especially due to the high prevalence of motor vehicle--and other accidents. Pathogenetic brain mechanisms following traumatic impact are usually investigated by using models of severe or moderate trauma. Apoptotic neuronal degeneration after notable brain trauma is a well-known phenomenon, but the source of its activation is not clear, especially after mild, subclinical brain trauma. In the present study, we used a closed head weight-drop model to induce minimal brain injury in mice. Pellets of 5, 10, 15, 20, 25 and 30 g were dropped on the right side of mice's head kept under light ether anesthesia. No abnormal behavioral or neurophysiological changes were seen following the head trauma. Morphological assessment was done 72 h after the traumatic impact using TUNEL assay and silver staining. We found gradual increase of TUNEL-positive and silver-impregnated cells number in different cortical and hippocampal regions of both injured and contralateral hemispheres. The threshold of traumatic impact that caused a significant activation was 10-15 g pellets (evident by silver staining), and 15-20 g for apoptosis. The most sensitive zones for trauma were anterior cingulate cortex and CA3 area of hippocampus. No bilateral hemispheric differences were found. Our results demonstrate that even closed head minimal traumatic brain injury can cause diffused neuronal damage and apoptosis. This results correlate well with cognitive and behavioral deficits described for mice suffering similar mTBI and can also explain the wide variety of mental disturbances described for post-concussion syndrome in patients who suffered mild head injury.

Network model of fear extinction and renewal functional pathways

The objective of this study was to examine the opposite behavior responses of conditioned fear extinction and renewal and how they are represented by network interactions between brain regions. This work is a continuation of a series of brain mapping studies of various inhibitory phenomena, including conditioned inhibition, blocking and extinction. A tone-footshock fear conditioning paradigm in rats was used, followed by extinction and testing in two different contexts. Fluorodeoxyglucose autoradiography was used to compare mean regional brain activity and interregional correlations resulting from the presentation of the extinguished tone in or out of the extinction context. A confirmatory structural equation model, constructed from a neural network proposed to underlie fear extinction, showed a reversal from negative regional interactions during extinction recall to positive interactions during fear renewal. Additionally, the magnitude of direct effects was different between groups, reflecting a change in the strength of the influences conveyed through those pathways. The results suggest that the extinguished tone encountered outside of the extinction context recruits auditory and limbic areas, which in turn influence the interactions of the infralimbic cortex with the amygdala and ventrolateral periaqueductal gray. Interestingly, the results also suggest that two independent pathways influence conditioned freezing: one from the central amygdaloid nucleus and the other from the infralimbic cortex directly to the ventrolateral periaqueductal gray.

Fear extinction in rats: Implications for human brain imaging and anxiety disorders

Fear extinction is the decrease in conditioned fear responses that normally occurs when a conditioned stimulus (CS) is repeatedly presented in the absence of the aversive unconditioned stimulus (US). Extinction does not erase the initial CS-US association, but is thought to form a new memory. After extinction training, extinction memory competes with conditioning memory for control of fear expression. Deficits in fear extinction are thought to contribute to post-traumatic stress disorder (PTSD). Herein, we review studies performed in rats showing that the medial prefrontal cortex plays a critical role in the retention and expression of extinction memory. We also review human studies indicating that prefrontal areas homologous to those critical for extinction in rats are structurally and functionally deficient in patients with PTSD. We then discuss how findings from rat studies may allow us to: (1) develop new fear extinction paradigms in humans, (2) make specific predictions as to the location of extinction-related areas in humans, and (3) improve current extinction-based behavioral therapies for anxiety disorders.

Regional differences of the prefrontal cortex in pediatric PTSD: an MRI study

Previous studies have revealed altered structural development of the frontal lobes and prefrontal cortex (PFC) in children with symptoms of posttraumatic stress disorder (PTSD). This study is the first to provide a detailed structural analysis of the PFC in children with and without PTSD symptoms. We compared gray and white matter volume in four subregions of the PFC between said groups, then explored whether volume was associated with PTSD symptom severity and functional impairment. PFC measurements were extracted from magnetic resonance imaging (MRI) data from a sample of 23 children (ages 7-14) with a history of trauma and symptoms of PTSD, who had undergone assessment for PTSD symptoms and functional impairment using the Child and Adolescent version of the Clinician-Administered PTSD Scale (CAPS-CA). These measurements were compared to data from an age-equivalent control group of 24 healthy children. Children with PTSD symptoms showed a significantly larger volume of gray matter in the delineated middle-inferior and ventral regions of the PFC than did control children. Decreased volume of gray matter in the dorsal PFC correlated with increased functional impairment scores. Results indicate that increased volume of the middle-inferior and ventral PFC may be associated with trauma and PTSD symptoms in children. Furthermore, the neuroanatomy of the dorsal PFC may influence the degree of functional impairment experienced by children with PTSD symptoms.

Early life stress and morphometry of the adult anterior cingulate cortex and caudate nuclei

BACKGROUND

Early life stress (ELS) is linked to adult psychopathology and may contribute to long-term brain alterations, as suggested by studies of women who suffered childhood sexual abuse. We examine whether reported adverse ELS defined as stressful and/or traumatic adverse childhood events (ACEs) is associated with smaller limbic and basal ganglia volumes.

METHOD

265 healthy Australian men and women without psychopathology or brain disorders were studied. ACEs were assessed by the ELSQ and current emotional state by the DASS. Anterior cingulate cortex (ACC), hippocampus, amygdala, and caudate nucleus volumes were measured from T1-weighted MRI. Analyses examined ROI volumetric associations with reported ACEs and DASS scores.

RESULTS

Participants with greater than two ACEs had smaller ACC and caudate nuclei than those without ACEs. A significant association between total ACEs and ROI volumes for these structures was observed. Regression analysis also revealed that ELS was more strongly associated than current emotional state (DASS) with these ROI volumes.

CONCLUSIONS

Reported ELS is associated with smaller ACC and caudate volumes, but not the hippocampal or amygdala volumes. The reasons for these brain effects are not entirely clear, but may reflect the influence of early stress and traumatic events on the developing brain.

Decreased anterior cingulate volume in combat-related PTSD

BACKGROUND

Neuroanatomical data point to functional relationships between the anterior cingulate cortex (ACC) and subcortical centers regulating fear, in particular, the amygdala. Functional brain imaging has disclosed divergent patterns of ACC activation in persons with posttraumatic stress disorder (PTSD). In addition, two preliminary structural imaging studies have found evidence of smaller ACC volume in PTSD. We explored associations between PTSD and ACC volume in a relatively large sample of adult combat veterans in which PTSD, lifetime alcohol abuse/dependence, and Vietnam versus Gulf War service were crossed.

METHODS

Subjects were US military combat veterans of the Vietnam and Gulf Wars recruited from two metropolitan areas served by allied Department of Veterans Affairs PTSD treatment/research centers. Anterior cingulate cortex volume was analyzed as a function of grouping factors with and without adjustment for body size.

RESULTS

Posttraumatic stress disorder was associated with smaller anterior cingulate cortex volume. This effect persisted in subjects without histories of alcoholism, did not interact with cohort effects, and was not modified by adjustment for body size.

CONCLUSIONS

Anterior cingulate cortex volume is substantially smaller in association with combat-related PTSD, a finding broadly consistent with cingulate hypofunctionality in that disorder.

Disrupted white matter tract integrity of anterior cingulate in trauma survivors

The objective of this study was to examine the integrity of whole-brain white matter in posttraumatic stress disorder patients. Twenty posttraumatic stress disorder patients who survived the Taegu subway fire incident and 20 healthy volunteers participated in this study. Statistical parametric mapping was used to evaluate the global differences in fractional anisotropy values between the two groups. The results show that posttraumatic stress disorder patients had significantly lower fractional anisotropy values in the left anterior cingulate regions. Posttraumatic stress disorder symptom severity negatively correlated to the level of decrease in anterior cingulate fractional anisotropy values. The outcome of the current study suggests that the disruption of the left anterior cingulate white matter tract integrity may play an important role in the pathophysiology of posttraumatic stress disorder.

Childhood post-traumatic stress disorder: an overview

This article presents an overview of post-traumatic stress disorder (PTSD) as it relates to children and adolescents. The authors provide a critical review of the pediatric PTSD literature regarding the definition, epidemiology, clinical presentation, assessment, neurobiologic foundation, and treatment of PTSD. The importance of developmental and neurobiologic factors and the uniqueness of these factors to children are emphasized.

Comparison of Anterior Cingulate and Primary Somatosensory Neuronal Responses to Noxious Laser-Heat Stimuli in Conscious, Behaving Rats

In this study, we investigated single-unit responses of the primary sensorimotor cortex (SmI) and anterior cingulate cortex (ACC) to noxious stimulation of the tail of the rat. The influences of morphine on these nociceptive responses were also compared. Multiple single-unit activities were recorded from two eight-channel microwire arrays chronically implanted in the tail region of the SmI and ACC, respectively. CO2laser-heat irradiation of the middle part of the tail at an intensity slightly higher than that causing a maximal tail flick response was used as a specific noxious stimulus. Examined individually, ACC neurons were less responsive than SmI neurons to laser-heat stimulus, in that only 51% of the ACC units ( n = 125) responded compared with 88% of the SmI units ( n = 74). Among these responsive ACC units, many had a very long latency and long-lasting excitatory type of response that was seldom found in the SmI. When ensemble activities were examined, laser heat evoked both short- (60 ∼ 150 ms) and long-latency (151 ∼ 600 ms) responses in the SmI and ACC. Latencies of both responses were longer in the ACC. Furthermore, a single dose of 2.5–10 mg/kg morphine intraperitoneally suppressed only the long latency response in the SmI, but significantly attenuated both responses in the ACC. These effects of morphine were completely blocked by prior treatment with the opiate receptor blocker, naloxone. These results provide further evidence suggesting that the SmI and ACC may play different roles in processing noxious information.

Single voxel proton magnetic resonance spectroscopy in women with and without intimate partner violence-related posttraumatic stress disorder

Preliminary in vivo proton magnetic spectroscopic ((1)H-MRS) studies of N-acetylaspartate (a putative marker of neuronal viability and function) in combat veterans and maltreated children with posttraumatic stress disorder (PTSD) suggest altered neuronal integrity in anterior cingulate and medial temporal lobe structures. In this study, (1)H-MRS was used to measure N-acetylaspartate (NAA), choline (Cho) and myo-inositol (mI) relative to creatine (Cr) in the anterior cingulate of 16 women with histories of intimate partner violence (7 with a DSM-IV diagnosis of PTSD, 9 without PTSD) and 11 healthy, non-abused comparison subjects. The relationship between anterior cingulate chemistry and performance on the Stroop Color-Word task and Part B of the Trail Making Test was also examined. There were no significant differences in anterior cingulate or occipital gray matter metabolite ratios of NAA/Cr and Cho/Cr between intimate partner violence and healthy comparison subjects. Intimate partner violence subjects with PTSD had significantly higher anterior cingulate Cho/Cr than intimate partner violence subjects without PTSD. There was evidence that the subjects with PTSD suffered more severe intimate partner violence as measured by the Conflict Tactics Scale-Revised. Metabolite ratios were not significantly correlated with performance on the Stroop or Trails B. Our findings, in agreement with earlier studies, showed significant alterations in anterior cingulate chemistry in women with PTSD. In contrast to other studies, we found an increase in Cho/Cr rather than a decrease in NAA/Cr, indicating alterations in glia, instead of neuronal dropout.

The psychobiology of neglect

Child neglect, the most prevalent form of child maltreatment, is associated with adverse psychological and educational outcomes. It is hypothesized that these outcomes may be caused by adverse brain development. However, there are very few published cross-sectional studies and no prospective studies that examine the neurodevelopmental consequences of neglect. In this article, the author comprehensively outlines the issues involved in the psychobiological research of child neglect. Pre-clinical and clinical studies will be reviewed. Throughout the article, suggestions for future research opportunities and novel ways to address methodological difficulties inherent in this field of study are offered. The results of recent neuroimaging studies of maltreated children may provide a basis for understanding the early effects of neglect on childhood brain development. The author is comprehensively examining these issues as part of the Federal Child Neglect Consortium.

Emotional memory: separating content and context

It is now well established that emotion enhances episodic memory. However, it remains unclear whether the same neural processes underlie enhancement of memory for both emotional stimuli and neutral stimuli encoded in an emotive context. We designed an experiment that specifically attempted to separate these effects and that was validated on 30 participants. We then used functional magnetic resonance imaging (fMRI) to examine the neural correlates of encoding and retrieval of the two classes of stimuli in 12 healthy male volunteers. We predicted that aversive emotional context would enhance memory regardless of content and that activation of anterior cingulate would be inversely related to retrieval of aversive items. Both predictions were supported. Furthermore we demonstrated apparent asymmetrical lateralisation of activation in the hippocampal/parahippocampal complex during recognition of words from aversive sentences: more left-sided activation for neutral words from aversive contexts, and more right-sided activation for aversive content words. These findings, if applicable to the wider population, may have application in a range of psychiatric disorders where interactions between emotion and cognition are relevant.

Single photon emission computed tomography (SPECT) of anxiety disorders before and after treatment with citalopram

BACKGROUND

Several studies have now examined the effects of selective serotonin reuptake inhibitor (SSRI) treatment on brain function in a variety of anxiety disorders including obsessive-compulsive disorder (OCD), posttraumatic stress disorder (PTSD), and social anxiety disorder (social phobia) (SAD). Regional changes in cerebral perfusion following SSRI treatment have been shown for all three disorders. The orbitofrontal cortex (OFC) (OCD), caudate (OCD), medial pre-frontal/cingulate (OCD, SAD, PTSD), temporal (OCD, SAD, PTSD) and, thalamic regions (OCD, SAD) are some of those implicated. Some data also suggests that higher perfusion pre-treatment in the anterior cingulate (PTSD), OFC, caudate (OCD) and antero-lateral temporal region (SAD) predicts subsequent treatment response. This paper further examines the notion of overlap in the neurocircuitry of treatment and indeed treatment response across anxiety disorders with SSRI treatment.

METHODS

Single photon emission computed tomography (SPECT) using Tc-99 m HMPAO to assess brain perfusion was performed on subjects with OCD, PTSD, and SAD before and after 8 weeks (SAD) and 12 weeks (OCD and PTSD) treatment with the SSRI citalopram. Statistical parametric mapping (SPM) was used to compare scans (pre- vs post-medication, and responders vs non-responders) in the combined group of subjects.

RESULTS

Citalopram treatment resulted in significant deactivation (p = 0.001) for the entire group in the superior (t = 4.78) and anterior (t = 4.04) cingulate, right thalamus (t = 4.66) and left hippocampus (t = 3.96). Deactivation (p = 0.001) within the left precentral (t = 4.26), right mid-frontal (t = 4.03), right inferior frontal (t = 3.99), left prefrontal (3.81) and right precuneus (t= 3.85) was more marked in treatment responders. No pattern of baseline activation distinguished responders from non-responders to subsequent pharmacotherapy.

CONCLUSIONS

Although each of the anxiety disorders may be mediated by different neurocircuits, there is some overlap in the functional neuro-anatomy of their response to SSRI treatment. The current data are consistent with previous work demonstrating the importance of limbic circuits in this spectrum of disorders. These play a crucial role in cognitive-affective processing, are innervated by serotonergic neurons, and changes in their activity during serotonergic pharmacotherapy seem crucial.

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.

Single photon emission computed tomography in posttraumatic stress disorder before and after treatment with a selective serotonin reuptake inhibitor

BACKGROUND

Posttraumatic stress disorder (PTSD) is recognized as a disorder mediated by specific neurobiological circuits. Functional imaging studies using script-driven trauma imagery and pharmacological challenges have documented altered cerebral function (activation and deactivation) in several brain regions, including the amygdala, hippocampus, prefrontal cortex and anterior cingulate. However, the neural substrates of PTSD remain poorly understood and the effect of selective serotonin reuptake inhibition on regional cerebral activity is deserving of further investigation.

METHODS

Eleven adult patients (seven men, four women) (mean age+S.D.=33.6+/-9.2 years) with a DSM-IV diagnosis of PTSD, as determined by the Structured Clinical Interview for DSM-IV (SCID-I) and the Clinician-Administered PTSD Scale (CAPS), underwent single photon emission computed tomography (SPECT) with Tc-99m HMPAO pre- and post-8 weeks of treatment with the selective serotonin reuptake inhibitor, citalopram. Symptoms were assessed at baseline and at 2-week intervals with the Clinician-Administered PTSD Scale (CAPS), Montgomery-Asberg Depression Rating Scale (MADRS), and the Clinical Global Impression Scale (CGI). Image analysis of baseline and post-treatment scans was performed using Statistical Parametric Mapping (SPM).

RESULTS

Treatment with citalopram resulted in significant deactivation in the left medial temporal cortex irrespective of clinical response. On covariate analysis, a significant correlation between CAPS score reduction and activation in the left paracingulate region (medial prefrontal cortex) was observed post-treatment. No significant pre-treatment differences were observed between responders and non-responders in anterior cingulate perfusion.

CONCLUSIONS

These preliminary findings are consistent with clinical data indicating temporal and prefrontal cortical dysfunction in PTSD and preclinical data demonstrating serotonergic innervation of these regions. However, further studies, in particular in vivo receptor imaging studies, are needed to confirm whether these regional abnormalities correlate with clinical features and treatment response.

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.

Chronic social stress: effects on limbic brain structures

Different types of stressors are known to activate distinct neuronal circuits in the brain. Acute physiological stimuli that are life threatening and require immediate reactions lead to a rapid stimulation of brainstem and hypothalamus to activate efferent visceral pathways. In contrast, psychological stressors activate higher-order brain structures for further interpretations of the perceived endangerment. Common to the later multimodal stressors is that they need cortical processing and, depending on previous experience or ongoing activation, the information is assembled within limbic circuits connecting, e.g., the hippocampus, amygdala and prefrontal cortex to induce neuroendocrine and behavioral responses. In view of the fact that stressful life events often contribute to the etiology of psychopathologies such as depressive episodes, several animal models have been developed to study central nervous mechanisms that are induced by stress. The present review summarizes observations made in the tree shrew chronic psychosocial stress paradigm with particular focus on neurotransmitter systems and structural changes in limbic brain regions.

WCA Recommendations for the long-term treatment of posttraumatic stress disorder

Posttraumatic stress disorder (PTSD) is a common and disabling condition. In addition to combat-related PTSD, the disorder occurs in civilians exposed to severe traumatic events, with the community prevalence rate for the combined populations reaching as high as 12%. If left untreated, PTSD may continue for years after the stressor event, resulting in severe functional and emotional impairment and a dramatic reduction in quality of life, with negative economic consequences for both the sufferer and society as a whole. Although PTSD is often overlooked, diagnosis is relatively straightforward once a triggering stressor event and the triad of persistent symptoms-reexperiencing the traumatic event, avoiding stimuli associated with the trauma, and hyperarousal have been identified. However, comorbid conditions of anxiety and depression frequently hamper accurate diagnosis. Treatment for PTSD includes psychotherapy and pharmacotherapy. The latter includes selective serotonin reuptake inhibitors (SSRIs), tricyclic antidepressants, and monoamine oxidase inhibitors. Only SSRIs have been proven effective and safe in long-term randomized controlled trials. Current guidelines from the Expert Consensus Panel for PTSD recommend treatment of chronic PTSD for a minimum of 12-24 months.

Voxel-based analysis of MRI reveals anterior cingulate gray-matter volume reduction in posttraumatic stress disorder due to terrorism

MRI studies using the manual tracing method have shown a smaller-than-normal hippocampal volume in patients with posttraumatic stress disorder (PTSD). However, these studies have yielded inconsistent results, and brain structures other than the hippocampus have not been well investigated. A recently developed, fully automated method called voxel-based morphometry enables an exploration of structural changes throughout the brain by applying statistical parametric mapping to high-resolution MRI. Here we first used this technology in patients with PTSD. Participants were 9 victims of the Tokyo subway sarin attack with PTSD and 16 matched victims of the same traumatic event without PTSD. The voxel-based morphometry showed a significant gray-matter volume reduction in the left anterior cingulate cortex (ACC) in trauma survivors with PTSD compared with those without PTSD. The severity of the disorder was negatively correlated with the gray-matter volume of the left ACC in PTSD subjects. There were no significant differences in other gray-matter regions or any of the white-matter regions between two groups. The present study demonstrates evidence for structural abnormalities of ACC in patients with PTSD. Together with previous functional neuroimaging studies showing a dysfunction of this region, the present findings provide further support for the important role of ACC, which is pivotally involved in attention, emotional regulation, and conditioned fear, in the pathology of PTSD.

Biologic findings of post-traumatic stress disorder and child maltreatment

Child maltreatment is a serious problem in US society, affecting approximately three million children. Children and adolescents exposed to child abuse and neglect experience high rates of post-traumatic stress disorder (PTSD). In addition, they are at risk for comorbid mental illness. Biologic stress systems affected in trauma and in PTSD are complex. Findings in cognitive testing, neuroimaging, and affected pathways shed light on the consequences of child maltreatment. What is known about treatment and outcomes for children with history of maltreatment and maltreatment-related PTSD indicates the need for prevention, intervention, and treatment of children exposed to abuse and neglect. The following is a brief review of the most recent neurobiologic findings in child maltreatment and related PTSD.

Recall of emotional states in posttraumatic stress disorder: an fMRI investigation

BACKGROUND

The goal of this study was to examine the neuronal circuitry underlying different emotional states (neutral, sad, anxious, and traumatic) in posttraumatic stress disorder (PTSD) in traumatized subjects versus traumatized subjects without PTSD.

METHODS

Traumatized subjects with (n = 10) and without (n = 10) PTSD were studied using the script-driven symptom provocation paradigm adapted to functional magnetic resonance imaging (fMRI) at a 4 Tesla field strength.

RESULTS

Compared to the trauma-exposed comparison group, PTSD subjects showed significantly less activation of the thalamus and the anterior cingulate gyrus (area 32) in all three emotional states (sad, anxious, and traumatic).

CONCLUSION

These findings suggest thalamic and anterior cingulate dysfunction in the recollection of traumatic as well as other negative events. Thalamic and anterior cingulate dysfunction may underlie emotion dysregulation often observed clinically in PTSD.

Quetiapine treatment in patients with posttraumatic stress disorder: an open trial of adjunctive therapy

In this 6-week, open-label trial, combat veterans meeting DSM-IV criteria for posttraumatic stress disorder (PTSD) were treated with the atypical antipsychotic quetiapine. The starting dose was 25 mg at bedtime with subsequent titration based on tolerability and clinical response. Primary outcome was measured using the Clinician Administered PTSD Scale (CAPS). Secondary assessments of efficacy included the Positive and Negative Symptom Scale (PANSS), the Hamilton Rating Scale for Depression, and the Clinical Global Impression Scale. Safety and tolerability evaluations included neurologic ratings, vital signs, and assessment of treatment-emergent side effects. Eighteen of 20 patients enrolled in the study completed 6 weeks of open-label treatment. The dose range of quetiapine was 25 to 300 mg daily, with an average of 100+/-70 mg/d. There was significant improvement in CAPS scores, from 89.8+/-15.7 to 67.5+/-21.0 (t=4.863, df=18, <0.005), and composite PANSS ratings from baseline to endpoint. General psychopathology (PANSS) and depressive symptoms (HRSD) were also reduced at the 6-week end point. There were no serious adverse events and no clinically significant changes in vital signs or neurologic ratings. This preliminary open trial suggests that quetiapine is well tolerated and may have efficacy in reducing PTSD symptoms in patients who have not had an adequate response other medications. Studies utilizing a randomized, controlled trial design and larger sample sizes are needed to better define the potential role of quetiapine and other atypical antipsychotics in the treatment of PTSD.

Brain structures in pediatric maltreatment-related posttraumatic stress disorder: a sociodemographically matched study

BACKGROUND

Previous investigations suggest that maltreated children evidence alterations of chemical mediators of stress and adverse brain development. Previous anatomical magnetic resonance imaging (MRI) brain studies have not controlled for socioeconomic status.

METHODS

In this study, 28 psychotropic naïve children and adolescents with maltreatment-related posttraumatic stress disorder (PTSD) and 66 sociodemographically similar healthy control subjects underwent comprehensive clinical assessments and anatomical MRI brain scans.

RESULTS

Compared with control subjects, subjects with PTSD had smaller intracranial, cerebral, and prefrontal cortex, prefrontal cortical white matter, and right temporal lobe volumes and areas of the corpus callosum and its subregions (2, 4, 5, 6, and 7), and larger frontal lobe cerebrospinal fluid (CSF) volumes than control subjects. The total midsagittal area of corpus callosum and middle and posterior regions remained smaller in subjects with PTSD, whereas right, left, and total lateral ventricles and frontal lobe CSF were proportionally larger than in control subjects, after adjustment for cerebral volume. Brain volumes positively correlated with age of onset of PTSD trauma and negatively correlated with duration of abuse. Significant gender x group effect demonstrated greater lateral ventricular volume increases in maltreated male subjects with PTSD than maltreated female subjects with PTSD. No hippocampal differences were seen.

CONCLUSIONS

These data provide further evidence to suggest that maltreatment-related PTSD is associated with adverse brain development. These data also suggest that male children may be more vulnerable to these effects.

Post-traumatic stress disorder in women: current concepts and treatments

In the US, 13% of women develop post-traumatic stress disorder (PTSD) during their lifetime. An accurate diagnosis of PTSD requires screening for trauma and symptoms of PTSD. Current research in the neurobiologic and psychologic responses to traumatic stress supports the use of pharmacologic and psychosocial interventions. Selective serotonin reuptake inhibitors are the current first-line pharmacotherapy. Efficacious psychosocial interventions include exposure therapy and cognitive processing therapy.

Neuroimaging studies in post-traumatic stress disorder

The past decade has seen a rapid advance in understanding of the neural circuits of post-traumatic stress disorder (PTSD), which has largely been due to the application of neuroimaging to the study of this disorder. Based on studies in animals of the effects of stress on the brain, dysfunction of the medial prefrontal cortex, hippocampus, and amygdala have been hypothesized to underlie symptoms of PTSD. Neuroimaging studies in PTSD have been consistent with these hypotheses, with the most replicated findings showing decreased medial prefrontal cortical function in PTSD. Other replicated findings include decreased inferior frontal gyrus function, decreased hippocampal function, increased posterior cingulate function, and, in some behavioral paradigms, increased amygdala function. Several studies have now shown changes in structure (smaller volume) of the hippocampus in PTSD. These studies are beginning to map out a neural circuitry of PTSD that may have future implications for diagnosis and treatment.

Dysregulation of the right brain: a fundamental mechanism of traumatic attachment and the psychopathogenesis of posttraumatic stress disorder

OBJECTIVE

This review integrates recent advances in attachment theory, affective neuroscience, developmental stress research, and infant psychiatry in order to delineate the developmental precursors of posttraumatic stress disorder.

METHOD

Existing attachment, stress physiology, trauma, and neuroscience literatures were collected using Index Medicus/Medline and Psychological Abstracts. This converging interdisciplinary data was used as a theoretical base for modelling the effects of early relational trauma on the developing central and autonomic nervous system activities that drive attachment functions.

RESULTS

Current trends that integrate neuropsychiatry, infant psychiatry, and clinical psychiatry are generating more powerful models of the early genesis of a predisposition to psychiatric disorders, including PTSD. Data are presented which suggest that traumatic attachments, expressed in episodes of hyperarousal and dissociation, are imprinted into the developing limbic and autonomic nervous systems of the early maturing right brain. These enduring structural changes lead to the inefficient stress coping mechanisms that lie at the core of infant, child, and adult posttraumatic stress disorders.

CONCLUSIONS

Disorganised-disoriented insecure attachment, a pattern common in infants abused in the first 2 years of life, is psychologically manifest as an inability to generate a coherent strategy for coping with relational stress. Early abuse negatively impacts the developmental trajectory of the right brain, dominant for attachment, affect regulation, and stress modulation, thereby setting a template for the coping deficits of both mind and body that characterise PTSD symptomatology. These data suggest that early intervention programs can significantly alter the intergenerational transmission of posttraumatic stress disorders.

Functional anatomical study of psychogenic amnesia

Psychogenic amnesia is characterized by an inability to recall information already stored in the patient's memory. It is usually related to a stressful or traumatic event that cannot be explained by manifest brain damage. To examine the underlying functional disturbance of brain areas in this condition, we performed a positron emission tomography (PET) activation study on a psychogenic amnesic patient and on 12 normal control subjects. A task requiring explicit retrograde memory of faces was compared with a control task. To assess functional modifications associated with the processes of recovery, a second PET study was performed on the patient 12 months after onset. During the task, activation of the right anterior medial temporal region including the amygdala was increased in the psychogenic amnesic patient. Activation of the bilateral hippocampal regions increased only in the control subjects. During recovery, the right anterior medial temporal region became less active while the right hippocampal region became more active. Activation levels also differed in the anterior cingulate cortex, prefrontal cortex and some other cortical regions between control subjects and the patient. These findings suggest that the changes in these limbic and limbic-cortical functions are related to symptoms of the psychogenic amnesia.

A pilot study of amygdala volumes in pediatric generalized anxiety disorder

BACKGROUND

The neurodevelopment of childhood anxiety disorders is not well understood. Basic research has implicated the amygdala and circuits related to these nuclei as being central to several aspects of fear and fear-related behaviors in animals.

METHODS

Magnetic resonance imaging was used to measure amygdala volumes and comparison brain regions in 12 child and adolescent subjects with generalized anxiety disorder and 24 comparison subjects. Groups were matched on age, sex, height, and handedness and were also similar on measures of weight, socioeconomic status, and full scale IQ.

RESULTS

Right and total amygdala volumes were significantly larger in generalized anxiety disorder subjects. Intracranial, cerebral, cerebral gray and white matter, temporal lobe, hippocampal, and basal ganglia volumes and measures of the midsagittal area of the corpus callosum did not differ between groups.

CONCLUSIONS

Although these data are preliminary and from a small sample, the results are consistent with a line of thinking that alterations in the structure and function of the amygdala may be associated with pediatric generalized anxiety disorder.