Neuroimaging studies in post-traumatic stress disorder

Post-traumatic stress is associated with verbal learning, memory, and psychomotor speed in HIV-infected and HIV-uninfected women

The prevalence of post-traumatic stress disorder (PTSD) is higher among HIV-infected (HIV+) women compared with HIV-uninfected (HIV-) women, and deficits in episodic memory are a common feature of both PTSD and HIV infection. We investigated the association between a probable PTSD diagnosis using the PTSD Checklist-Civilian (PCL-C) version and verbal learning and memory using the Hopkins Verbal Learning Test in 1004 HIV+ and 496 at-risk HIV- women. HIV infection was not associated with a probable PTSD diagnosis (17% HIV+, 16% HIV-; p = 0.49) but was associated with lower verbal learning (p < 0.01) and memory scores (p < 0.01). Irrespective of HIV status, a probable PTSD diagnosis was associated with poorer performance in verbal learning (p < 0.01) and memory (p < 0.01) and psychomotor speed (p < 0.001). The particular pattern of cognitive correlates of probable PTSD varied depending on exposure to sexual abuse and/or violence, with exposure to either being associated with a greater number of cognitive domains and a worse cognitive profile. A statistical interaction between HIV serostatus and PTSD was observed on the fine motor skills domain (p = 0.03). Among women with probable PTSD, HIV- women performed worse than HIV+ women on fine motor skills (p = 0.01), but among women without probable PTSD, there was no significant difference in performance between the groups (p = 0.59). These findings underscore the importance of considering mental health factors as correlates to cognitive deficits in women with HIV.

Amygdala Volume in Offspring from Multiplex for Alcohol Dependence Families: The Moderating Influence of Childhood Environment and 5-HTTLPR Variation

BACKGROUND

The increased susceptibility for developing alcohol dependence seen in offspring from families with alcohol dependence may be related to structural and functional differences in brain circuits that influence emotional processing. Early childhood environment, genetic variation in the serotonin transporter-linked polymorphic region (5-HTTLPR) of the SLCA4 gene and allelic variation in the Brain Derived Neurotrophic Factor (BDNF) gene have each been reported to be related to volumetric differences in the temporal lobe especially the amygdala.

METHODS

Magnetic resonance imaging was used to obtain amygdala volumes for 129 adolescent/young adult individuals who were either High-Risk (HR) offspring from families with multiple cases of alcohol dependence (N=71) or Low-Risk (LR) controls (N=58). Childhood family environment was measured prospectively using age-appropriate versions of the Family Environment Scale during a longitudinal follow-up study. The subjects were genotyped for Brain-Derived Neurotrophic Factor (BDNF) Val66Met and the serotonin transporter polymorphism (5-HTTLPR). Two family environment scale scores (Cohesion and Conflict), genotypic variation, and their interaction were tested for their association with amygdala volumes. Personal and prenatal exposure to alcohol and drugs were considered in statistical analyses in order to more accurately determine the effects of familial risk group differences.

RESULTS

Amygdala volume was reduced in offspring from families with multiple alcohol dependent members in comparison to offspring from control families. High-Risk offspring who were carriers of the S variant of the 5-HTTLPR polymorphism had reduced amygdala volume in comparison to those with an LL genotype. Larger amygdala volume was associated with greater family cohesion but only in Low-Risk control offspring.

CONCLUSIONS

Familial risk for alcohol dependence is an important predictor of amygdala volume even when removing cases with significant personal exposure and covarying for prenatal exposure effects. The present study provides new evidence that amygdala volume is modified by 5-HTTLPR variation in High-Risk families.

A gedanken experiment to find a neuroanatomical model for post-traumatic stress disorder

Post-traumatic stress disorder is a persistent stress syndrome in which abnormal brain physiology persists long after cessation of the acute psychological event that causes it. Normal physiological homeostasis depends on equilibria. The basic unit of equilibrium is the negative feedback loop (NFL) and the simplest way to disrupt homeostasis would be to break an NFL. The resulting model requires two nuclei in the brain reciprocally-connected in an NFL, one of which, in response to the perception of overwhelming threats or demands, generates rapid pacemaker firing which leads to excitotoxic cell death in the other. The injured nucleus must also be able to undergo neurogenesis, which would explain clinical recovery. The relevant site of neurogenesis is the hippocampus, which is reciprocally connected with the dorsal raphe nucleus (DRN), a serotonergic pacemaker nucleus which has been shown to light up on PET scan (i.e. undergo burst firing) in response to stress. The model postulates that the DRN delivers an excitotoxic blow to the hippocampus. Then, via a second pathway, it promotes neurogenesis. The model incorporates potential sites of action for several psychoactive drugs, including anti-depressants and lithium, which promote neurogenesis; and valproate and atypical anti-psychotics, which block excitotoxicity. The theory has the advantage of being formulated in terms of how the brain actually works, i.e. through the interaction between pacemakers and processed sensory input from the outside world. It also directs pharmacological thinking to the role played by pacemakers and pacemaker currents.

A terrified-sound stress induced proteomic changes in adult male rat hippocampus

In this study, we investigated the biochemical mechanisms in the adult rat hippocampus underlying the relationship between a terrified-sound induced psychological stress and spatial learning. Adult male rats were exposed to a terrified-sound stress, and the Morris water maze (MWM) has been used to evaluate changes in spatial learning and memory. The protein expression profile of the hippocampus was examined using two-dimensional gel electrophoresis (2DE), matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, and bioinformatics analysis. The data from the MWM tests suggested that a terrified-sound stress improved spatial learning. The proteomic analysis revealed that the expression of 52 proteins was down-regulated, while that of 35 proteins were up-regulated, in the hippocampus of the stressed rats. We identified and validated six of the most significant differentially expressed proteins that demonstrated the greatest stress-induced changes. Our study provides the first evidence that a terrified-sound stress improves spatial learning in rats, and that the enhanced spatial learning coincides with changes in protein expression in rat hippocampus.

Event-related potentials to auditory stimuli in monozygotic twins discordant for combat: association with PTSD

Studies have demonstrated ERP abnormalities related to concentration difficulties in post-traumatic stress disorder (PTSD). We used an identical-twin, case-control design to investigate whether these abnormalities reflect pre-trauma vulnerability or the acquired consequence of PTSD. Vietnam combat veterans and their non-combat-exposed, identical twins completed a three-tone oddball task. Veterans with PTSD had delayed target N2 latencies compared to veterans without PTSD. In a small nonmedicated, nonsmoking subsample, veterans with PTSD also had significantly diminished target P3b amplitudes. A mixed-model, random-effects analysis on the nonmedicated, nonsmoking subsample that included the combat-unexposed co-twins showed a significant Diagnosis x Combat Exposure interaction for target P3b amplitude. Results replicate increased N2 latency and diminished P3b amplitude in PTSD and suggest that diminished P3b amplitude is an acquired condition in PTSD.

Functional activation and neural networks in women with posttraumatic stress disorder related to intimate partner violence

BACKGROUND

Intimate partner violence (IPV) is one of the most common causes of posttraumatic stress disorder (PTSD) in women. Victims of IPV are often preoccupied by the anticipation of impending harm. This investigation tested the hypothesis that IPV-related PTSD individuals show exaggerated insula reactivity to the anticipation of aversive stimuli.

METHODS

Fifteen women with a history of IPV and consequent PTSD (IPV-PTSD) and 15 non-traumatized control (NTC) women performed a task involving cued anticipation to images of positive and negative events during functional magnetic resonance imaging.

RESULTS

Both groups showed increased activation of bilateral anterior insula during anticipation of negative images minus anticipation of positive images. Activation in right anterior/middle insula was significantly greater in the IPV-PTSD relative to the NTC group. Functional connectivity analysis revealed that changes in activation in right middle insula and bilateral anterior insula were more strongly associated with amygdala activation changes in NTC than in IPV-PTSD subjects.

CONCLUSIONS

This study revealed increased activation in the anterior/middle insula during negative anticipation in women with IPV-related PTSD. These findings in women with IPV could be a consequence of the IPV exposure, reflect pre-existing differences in insular function, or be due to the development of PTSD. Thus, future longitudinal studies need to examine these possibilities.

Reduced mismatch negativity in posttraumatic stress disorder: a compensatory mechanism for chronic hyperarousal?

Mismatch Negativity (MMN) is yet poorly understood in the context of Posttraumatic Stress Disorder (PTSD, e.g. [Morgan 3rd, C.A., Grillon, C., 1999. Abnormal mismatch negativity in women with sexual assault-related posttraumatic stress disorder. Biol. Psychiatry 45, 827-832.]). PTSD symptoms like hyperarousal, emotional pressure and avoidance may interfere with pre-attentive sensory processing. We tested this in an optimized MMN design [Näätänen, R., Pakarinen, S., Rinne, T., Takegata, R. (2004) The mismatch negativity (MMN): towards the optimal paradigm. Clin. Neurophysiol. 115: 140-144.] with PTSD victims and a control group without PTSD. A group of PTSD subjects was compared with gender and age-matched, healthy comparison subjects without PTSD. A "memory trace" was elicited by frequently presented "standard" auditory stimuli (50% occurrence) of 1 kHz, 75 ms duration, intermittently with 8 rare "deviants", which differed in frequency (higher/lower), intensity (louder/softer), duration (shorter), direction (left/right) or by the presence of a gap in the sound. During presentation of tones a silent film was shown. Psychometric data were collected by SCID, BSI, Attentiveness Inventory, Edinburgh Handedness Questionnaire, and the PTSD Screening Scale by Breslau et al. [Breslau, N., Peterson, E.L., Kessler, R.C., Schultz, L.R. (1999) Short screening scale for DSM-IV posttraumatic stress disorder. Am. J. Psychiatry 156: 908-911.]. Group comparisons of the MMN were performed for left/right-frontal/temporal, and for midline electrode sites. A good differentiation of both groups was found in psychometric and electrophysiological data. The PTSD group revealed on most BSI scales enhanced values of psychic aberration. The amplitude of the MMN was significantly reduced in the PTSD compared to non-PTSD subjects. MMN was significantly correlated with the total PTSD score. The data suggest a reduction in pre-attentive auditory sensory memory in PTSD due to specific symptom variables such as hyperarousal, sleeplessness, impaired concentration and a general enhanced excitation of the nervous system. This protective inhibition is thought to be a fine-tuning process in PTSD in order to prevent arousal overload.

The genetic background to PTSD

Although extensive research has already been done on the genetic bases of psychiatric disorders, little is known about polygenetic influences in posttraumatic stress disorder (PTSD). This article reviews molecular genetic studies relating to PTSD that were found in a literature search in Medline, Embase and Web of Science. Association studies have investigated 8 major genotypes in connection with PTSD. They have tested hypotheses involving key candidate genes in the serotonin (5-HTT), dopamine (DRD2, DAT), glucocorticoid (GR), GABA (GABRB), apolipoprotein systems (APOE2), brain-derived neurotrophic factor (BDNF) and neuropeptide Y (NPY). The studies have produced inconsistent results, many of which may be attributable to methodological shortcomings and insufficient statistical power. The complex aetiology of PTSD, for which experiencing a traumatic event forms a necessary condition, makes it difficult to identify specific genes that substantially contribute to the disorder. Gene-finding strategies are difficult to apply. Interactions between different genes and between them and the environment probably make certain people vulnerable to developing PTSD. Gene-environmental studies are needed that focus more narrowly on specific, distinct endophenotypes and on influences from environmental factors.

Intimate partner violence, PTSD, and adverse health outcomes

The high prevalence of adverse health outcomes related to intimate partner violence (IPV) is well documented. Yet we know little about the pathways that lead to adverse health outcomes. Research concerning the psychological, biological, neurological, behavioral, and physiological alterations following exposure to IPV--many of which are associated with posttraumatic stress disorder (PTSD)--represents a promising area of empirical discovery. New technologies and interdisciplinary collaborative efforts are required to integrate diverse methodologies and to apply new findings to improving the health and well being of those affected by IPV. This article focuses on victimization by IPV and addresses the most important research findings in the last 20 years (health and mental health burden of IPV), the most important research issue for the next decade (pathways between IPV and adverse health outcomes), and the most promising methodological innovation for the study of IPV (integrated, interdisciplinary, biobehavioral methodology).

The Relationship Between Hippocampal Volume and Declarative Memory in a Population of Combat Veterans With and Without PTSD

Both reduced hippocampal volume and cognitive alterations have been found in posttraumatic stress disorder (PTSD). The purpose of this article was to examine the relationship between hippocampal volume, combat exposure, symptom severity, and memory performance in a sample of combat veterans with and without a history of PTSD. Subjects were 33 male veteran volunteers (16 PTSD+, 17 PTSD-) who underwent an MRI and neuropsychological testing with the California Verbal Learning Test (CVLT), a measure of declarative memory. Relationships between hippocampal volume (i.e., right + left hippocampal volume/whole brain volume) and performance on the CVLT were determined using partial correlational analysis controlled for age and Wechsler Adult Intelligence Scale, Third Edition (WAIS-III) vocabulary scores. Percent hippocampal volume for the entire sample was positively associated with several aspects of memory performance as reflected by the CVLT. In the PTSD+ group, CVLT performance was negatively correlated with lifetime, but not current CAPS symptoms. CVLT performance appears to be strongly correlated with hippocampal volume in a group of trauma survivors with and without PTSD. Insofar as CVLT performance in the PTSD group was negatively associated with worst episode, but not to current PTSD symptoms, memory performance in combat veterans may reflect some aspect of risk related to the magnitude of the psychological response to trauma, rather than current symptoms that may be interfering with cognitive performance. It will be of interest to study cognitive abilities that may relate to the likelihood of specific PTSD symptoms and to track changes in CVLT performance and hippocampal volume over time in persons with and without a history of trauma exposure.

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.

Early life trauma decreases glucocorticoid receptors in rat dentate gyrus upon adult re-stress: reversal by escitalopram

Early exposure to adverse experiences may lead to specific changes in hippocampal glucocorticoid function resulting in abnormalities within the hypothalamic-adrenal axis. Given interactions between the neuroendocrine and central serotonergic systems, we hypothesized that exposure to early trauma would lead to abnormal hypothalamic-adrenal axis activity that would be normalized by pretreatment with a selective serotonin re-uptake inhibitor. Hypothalamic-adrenal axis function was assessed by determining basal corticosterone levels and hippocampal glucocorticoid receptor immunoreactivity. Rats were subjected to a triple stressor on postnatal day 28, and again to a single swim re-stress session on postnatal day 35 and postnatal day 60. On postnatal day 61 i.e. 24 h after the last re-stress, trunk blood was collected for serum corticosterone determinations and hippocampal tissue was collected for immunohistochemistry of glucocorticoid receptors. Escitalopram (5mg/kg) or saline vehicle was administered from postnatal day 47-postnatal day 60 via osmotic mini-pumps. Animals exposed to early life trauma showed an increase in basal corticosterone levels, and a significant decrease in the ratio of glucocorticoid receptor positive cells to total cells in the hilus, granule cell layer and the dentate gyrus. Both the increase in basal corticosterone and decrease in glucocorticoid receptor immunoreactivity were reversed by escitalopram pretreatment. These data confirm alterations in hypothalamic-adrenalaxis function that may stem from decreases in glucocorticoid receptor levels, in response to early adverse experiences, and demonstrate that these alterations are reversed by serotonin re-uptake inhibitor pretreatment.

The pathogenesis of clinical depression: stressor- and cytokine-induced alterations of neuroplasticity

Stressful events promote neurochemical changes that may be involved in the provocation of depressive disorder. In addition to neuroendocrine substrates (e.g. corticotropin releasing hormone, and corticoids) and central neurotransmitters (serotonin and GABA), alterations of neuronal plasticity or even neuronal survival may play a role in depression. Indeed, depression and chronic stressor exposure typically reduce levels of growth factors, including brain-derived neurotrophic factor and anti-apoptotic factors (e.g. bcl-2), as well as impair processes of neuronal branching and neurogenesis. Although such effects may result from elevated corticoids, they may also stem from activation of the inflammatory immune system, particularly the immune signaling cytokines. In fact, several proinflammatory cytokines, such as interleukin-1, tumor necrosis factor-alpha and interferon-gamma, influence neuronal functioning through processes involving apoptosis, excitotoxicity, oxidative stress and metabolic derangement. Support for the involvement of cytokines in depression comes from studies showing their elevation in severe depressive illness and following stressor exposure, and that cytokine immunotherapy (e.g. interferon-alpha) elicited depressive symptoms that were amenable to antidepressant treatment. It is suggested that stressors and cytokines share a common ability to impair neuronal plasticity and at the same time altering neurotransmission, ultimately contributing to depression. Thus, depressive illness may be considered a disorder of neuroplasticity as well as one of neurochemical imbalances, and cytokines may act as mediators of both aspects of this illness.

Relationship between cortisol and age-related memory impairments in Holocaust survivors with PTSD

RATIONALE

Holocaust survivors with PTSD appear to show an accelerated aging effect as evidenced by their performance on tests of explicit memory, and also show more exaggerated patterns on age-related alterations in cortisol release over the diurnal cycle than Holocaust survivors without PTSD and nonexposed subjects. To investigate the implications of age-related HPA axis alterations on cognition, we examined correlations between parameters reflecting circadian cortisol release and implicit and explicit memory performance.

METHODS

Nineteen Holocaust survivors with PTSD (7 men, 12 women), 16 Holocaust survivors without PTSD (7 men, 9 women), and 28 non-exposed healthy comparison subjects (13 men, 15 women) collected salivary samples at six times over the diurnal cycle, and were tested with Paired Associates and Word Stem Completion Tests.

RESULTS

Negative correlations were observed between several measures of salivary cortisol concentrations and explicit memory in Holocaust survivors with PTSD after adjusting for IQ, years of education and current age reflecting poorer performance in association with higher cortisol levels. This relationship was absent in Holocaust survivors without PTSD and in demographically-comparable subjects who were not exposed to the Holocaust or other extremely traumatic events.

CONCLUSION

The significantly different relationship between cortisol and memory performance in these groups suggests that the neuropsychological impairments observed in Holocaust survivors with PTSD may reflect an interaction of PTSD and aging effects.

Auditory inhibitory gating in the amygdala: Single-unit analysis in the behaving rat

Inhibitory sensory gating has been proposed to be a fundamental physiological process that filters neural input. Its temporal properties could allow for a rapid influence on vigilance and attention processes. Inhibitory mechanisms are reflected by reductions in neural responsiveness to repeated and well-predicted stimuli; for auditory gating, this translates into an inhibition of the neural activation to subsequent tone stimuli embedded within sequential and identical tone presentations. Here we expand previous neurophysiological data on inhibitory gating by examining gating in the amygdala using single-unit recording in freely moving animals. Previous data have shown the amygdala to be important in mediating rapid auditory sensory processing involved in emotional conditioning. We measured inhibitory gating with two matching auditory tones presented in a repetitive fashion (10 ms tones, ISI = 500 ms and 10 s between pairs) for 1 h (360 pairs). The majority of the tone responsive units showed inhibitory gating (78/95 units) located in both the medial and lateral subnuclei of the amygdala. Different types of tone responses were gated, including both shorter- and longer-duration excitatory tone responses as well as inhibitory tone responses. Different degrees of gating were found ranging from 100% inhibition (complete gating category) to 25% inhibition (graded gating category). The degree of gating varied over short-term and long-term time intervals. These findings demonstrate the existence of inhibitory gating in the amygdala and provide a detailed description of the basic properties of this rapid neural inhibition that could play an important role in filtering stimulus input.

The concept of post-traumatic mood disorder

Post-traumatic stress disorder (PTSD) is frequently comorbid with depression. A number of studies have been conducted to compare individuals suffering from comorbid PTSD and depression with individuals suffering from PTSD alone or depression alone. Comorbidity of PTSD and depression is associated with more severe symptoms as well as higher levels of disability compared to individuals with PTSD alone. A severity of overall symptoms is three to fivefold greater in subjects with comorbid PTSD and depression compared to those with PTSD alone. The comorbid group is five times more likely to manifest functional impairment compared to those diagnosed with PTSD alone. Patients with comorbid PTSD and depression have higher depression, impulsivity, and hostility scores and are significantly more likely to make a suicide attempt compared to subjects with depression alone. Depressed subjects with comorbid PTSD tend towards earlier age of first hospitalization and a higher number of hospitalizations compared to depressed individuals without comorbid PTSD. Lower affinity of alpha-2 adrenoreceptors and higher plasma tyrosine availability to the brain are associated with comorbid PTSD and depression, but not with PTSD alone. Individuals with comorbid PTSD and depression do not exhibit the classic rapid eye movement sleep architectural modifications associated with depression, despite the fact that several other psychophysiological indices of dysphoria are detectable in their sleep. In fenfluramine challenge studies, depressed patients with comorbid PTSD have lower plasma cortisol compared to depressed patients without comorbid PTSD. Cortisol levels increase with age and the number of previous major depressive episodes is a predictor of the cortisol response to fenfluramine administration in depressed patients without PTSD, but not in depressed patients with comorbid PTSD. Depressed subjects with comorbid PTSD have higher cerebrospinal fluid homovanillic acid levels compared with depressed subjects without comorbid PTSD. Thus, studies suggest that patients suffering from comorbid PTSD and depression differ clinically and biologically from individuals with PTSD alone or depression alone. It is possible that some or all individuals diagnosed with comorbid PTSD and depression have a separate psychobiological condition that can be termed "post-traumatic mood disorder". Future clinical and neurobiological studies may not only advance our understanding of the role of environmental and genetic factors in the etiology and pathogenesis of stress-related disorders, but also be useful in refining conceptions of stress-related disorders themselves and possible approaches to the treatment of these conditions.

Global-local visual processing in posttraumatic stress disorder

The purpose of this study was to examine a behavioral index of hemispheric asymmetry (i.e., visual hierarchical attention) in posttraumatic stress disorder (PTSD), a disorder characterized by anxiety and other emotional symptoms. A reaction time based, computerized, global-local visual paradigm was administered to 26 PTSD-diagnosed and 22 psychopathology-free right-handed, male Vietnam War zone veterans. Results indicated that PTSD-diagnosed veterans displayed slower reaction times to all targets than the no-mental disorders comparison sample. However, findings also revealed a Group x Target location interaction in which the PTSD group was slower than the no-disorders comparison sample to respond to local, but not global, targets. Moreover, relative global bias was greater among PTSD-diagnosed veterans than their no-diagnosis counterparts. Findings provide partial support for the hypothesis that PTSD may be associated with a functional cerebral asymmetry favoring the right hemisphere.

Clinical correlates of neurological change in posttraumatic stress disorder: an overview of critical systems

Knowledge about the biological basis of psychological trauma is changing at an exponential rate. A PsychlNFO search on the search terms "locus coeruleus" and "PTSD" revealed one peer-reviewed journal article between 1982 and 1992 and 51 in the subsequent decade. A similar search revealed zero articles on "hippocampus" and "PTSD" between 1982 and 1992 and 170 in the past decade. As clinicians, it is important to become increasingly familiar with this growing literature to use that knowledge to treat and educate patients. Imagine the relief that can be provided to survivors of trauma if clinicians can tell them that they have a good idea about what causes their symptoms and even clearer ideas about how to treat them.One ancillary but invaluable outcome to this work is the fact that understanding the neurological underpinnings of PTSD will go a long way to establishing a necessary equilibrium in nature and nurture's role in the etiology and maintenance of the disorder. In its early conceptualization, PTSD was thought by many to be an ordinary reaction to an extraordinary event, thus placing responsibility for the disorder firmly in the hands of environmental factors. A subsequent emphasis on vulnerability and resiliency factors in the disorder, however, gave the impression that genetic and potentially hard-wired neurological factors were dominant in the expression of the disorder. Appreciating the balance between nature and nurture in the development of stress disorders like PTSD will allow clinicians and patients alike to appreciate the role of personal responsibility in the process of recovery. A parallel, albeit more mature process, has occurred in the area of schizophrenia in the past four decades. Early conceptualizations of schizophrenia placed a heavy burden on parenting and behavioral factors, leaving the patients angry at their parents and parents with unnecessary guilt. The later dominance of genetic and biological theories in the disorder allayed parents of their guilt, but left both parents and patients wondering what might be done in the face of such an affliction. Modern theories of schizophrenia seem to have achieved an appropriate balance that recognizes biological vulnerabilities, but also emphasizes familial and patient responsibilities in recovery and care. In PTSD, a similar equilibrium needs to be found, and understanding the neurobiology of the disorder will go far in achieving that goal. When it is understood how trauma affects the brain and how treatment produces neurobiological changes that may remediate trauma-related effects, the patient will be in a better position to make choices about what can and cannot be done in the process of recovery. Giving patients this critical internal locus of control will provide therapeutic benefits such as confidence,self-esteem, and hope that are likely to enhance changes that occur with intervention.

Posttraumatic stress disorder: psychopathology, medical management, and dental implications

PTSD is a chronic mental illness that may arise after an individual experiences or witnesses a life-threatening event. Symptoms consist of persistent reexperiencing of the event, avoidance of reminders of the event, a numbing of positive emotions, and social withdrawal. A depressed mood and excessive use of alcohol and tobacco may accompany the disorder. PTSD afflicts approximately 5% of men and 11% of women. Dental disease may be extensive because of neglect of oral hygiene compounded by cigarette smoking. Dental treatment includes preventive education, oral cancer screening, and prescribing saliva substitutes or stimulants and anticaries agents to combat medication-induced xerostomia. Precautions must be taken when prescribing or administering certain analgesics, antibiotics, or sedative agents that may adversely interact with the psychiatric medications or when performing surgery because of the long-term effects of alcohol abuse.

Mineralocorticoid Receptor-Mediated Inhibition of the Hypothalamic-Pituitary-Adrenal Axis in Aged Humans

In aged humans, diminished mineralocorticoid receptor (MR)-mediated feedback in the brain could contribute to impaired feedback regulation of the hypothalamic-pituitary-adrenal (HPA) axis, but no study specifically compared young and old individuals with regard to MR function. We examined 10 healthy young (mean age +/- SD [standard deviation] 26.1 +/- 2.9 years) and 10 elderly men (68.3 +/- 4.7 years) at the nadir of cortisol levels (2:00 pm-9:00 pm) when HPA activity is mainly controlled by the MR. After pretreatment with 3 g metyrapone to minimize the impact of basal endogenous cortisol secretion, participants received orally, in randomized order on two separate occasions, either 0.5 mg of the MR agonist fludrocortisone or placebo. Fludrocortisone significantly decreased maximum adrenocorticotropic hormone (ACTH) and cortisol concentrations in both groups. ACTH and cortisol values after fludrocortisone were significantly higher in older men compared with young men. Our results implicate that a decrease in MR-mediated negative feedback contributes to the diminished feedback activity in older humans.

Activation of the prefrontal cortex to trauma-related stimuli measured by near-infrared spectroscopy in posttraumatic stress disorder due to terrorism

To develop a noninvasive method for psychophysiological assessment of posttraumatic stress disorder (PTSD), 34 victims of the Tokyo Subway Sarin Attack in 1995 including 8 diagnosed as PTSD and 12 controls were examined by a multichannel near-infrared spectroscopy (NIRS) system. Hemodynamic response in the prefrontal cortex was monitored during the presentation of trauma-related and control stimuli by video images. Skin conductance response (SCR) was also examined. Oxygenated hemoglobin significantly increased during the trauma-related image in the victims with or without PTSD. Deoxygenated hemoglobin significantly decreased only in victims with PTSD. No significant alteration was found in controls. Significantly enhanced SCR was also observed in the victims with PTSD during trauma-related stimuli. The findings suggest that measurement of cerebral hemodynamic response by NIRS is useful for psychophysiological assessment of PTSD.

Anxiety disorders: treatment considerations

Anxiety disorders are among the most prevalent and disabling psychiatric disorders. Today patients have a plethora of treatment options to manage these potentially disabling and costly psychiatric disorders. Anxiety disorders represent a large portion of primary care visits and diverse practice settings. Nurses are in key positions to identify symptoms of various anxiety disorders, initiate appropriate treatment, or refer patients for treatment. Families play a key role in successful treatment planning and must be an integral part of the health care team. Major nursing interventions must focus on making an accurate diagnosis, initiating appropriate treatment, and facilitating a higher level of functioning and quality of life.